fix(escrow): lock min-ada for the largest future datum so long-capability Submits settle

The escrow locks payment + both bonds and the validator requires exact
value preservation (value_equal) on Claim and Submit. Submit grows the
inline datum ~43 bytes (submitted_at None->Some, result_receipt_hash
None->Some 32 bytes). When capability_id is long enough, the
Submitted-state output's min-ada exceeds the locked total; lucid bumps
the continuing output, value_equal fails, and the validator errors with
no traces (opaque evaluateTransaction 3010/3012). Measured on mainnet at
utxoCostPerByte 4310: a 20-byte chat capability clears a 2.2M lock by
49,310, a 33-byte OCR capability is over by 11,030 - so short-capability
escrows settle and long ones never can, and because Claim's datum is
smaller it always passes, making a Submit-only failure look chain-side.

escrowLockFloor() computes min-ada for the Submitted state plus a margin
and locks max(economic total, that floor) in the post builders. Buyer-
side only, no contract or supplier changes; lucid never bumps once the
lock is sufficient, and the surplus returns through the >= terminal
distribution. postOcrEscrow's identical change ships with the OCR
feature branch. New unit test covers the floor across capability lengths.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.gitignore

@@ -11,9 +11,21 @@ coverage
 !.env.*.example
 
 # Local data / caches (matches at any depth — covers
-# deploy/simulation/data/, indexer/data/, etc.)
+# deploy/simulation/data/, indexer/data/, wallet-monitor/data/, etc.)
 data/
 *.log
+
+# wallet-monitor: the real wallet list holds production mainnet addresses —
+# keep it out of git; only wallets.example.json is committed.
+wallet-monitor/wallets.json
+
+# Generated wallet key dumps (e.g. tx:gen-keypair output, supplier/.deepseek-wallet.json)
+# — these contain privateKeyHex. Never commit.
+*-wallet.json
+
+# Operator local file backups (e.g. docker-compose.buyer.yml.bak-20260609)
+*.bak
+*.bak-*
 .vitest-cache
 .DS_Store
 

README.md

@@ -1,3 +1,36 @@
-## Local Agents Marketplace
+# Local Agents Marketplace
 
-Local Agents Marketplace MVP. See `docs/ARCHITECTURE.md` for the architecture spec. Monorepo managed with pnpm workspaces. Work-in-progress; not production-ready.
+Bonded-escrow coordination for AI agent work on **Vector**, the Apex Fusion eUTXO L2.
+
+Buyers commission work. Suppliers claim it. Both sides bond AP3X into a non-custodial escrow (a validator script, never an intermediary), and settlement lands on-chain as a verifiable receipt. Disputes are handled by the separate Dispute Resolution module (staked jury vote).
+
+**Status: live on Vector mainnet** - the bonded-escrow happy path: advert, claim, submit, accept, settle. The contracts have been through the internal audit pipeline (methodology published in [vector-ai-agents](https://github.com/Apex-Fusion/vector-ai-agents)); they have not yet undergone independent third-party audit.
+
+## Flow
+
+1. **Advert** - a buyer posts a job with escrow bonded
+2. **Claim** - a supplier claims it, bonding their side
+3. **Submit** - work is delivered
+4. **Accept** - the buyer accepts the work
+5. **Settle** - the escrow releases; the settlement is a signed on-chain receipt
+
+## Repository layout
+
+| Path | What |
+|---|---|
+| `contracts/advert`, `contracts/escrow`, `contracts/marketplace` | Aiken validators |
+| `docs/ARCHITECTURE.md` | Architecture spec |
+| `docs/buyer/`, `docs/supplier/` | Role guides |
+| `deploy/` | Deployment and simulation tooling |
+
+Monorepo managed with pnpm workspaces.
+
+## Getting started
+
+Developer docs: [Vector AI documentation](https://apex-fusion.github.io/vector-ai-documentation/). For the contract-level picture, start with [`docs/ARCHITECTURE.md`](docs/ARCHITECTURE.md).
+
+## Related
+
+- [mcp-server](https://github.com/Apex-Fusion/mcp-server) - hosted MCP server for Vector (testnet and mainnet)
+- [agent-sdk-py](https://github.com/Apex-Fusion/agent-sdk-py) / [agent-sdk-ts](https://github.com/Apex-Fusion/agent-sdk-ts) - Python and TypeScript SDKs
+- [vector-agent-modules](https://github.com/Apex-Fusion/vector-agent-modules) - dispute resolution, reputation staking, self-improvement

buyer/package.json

@@ -3,6 +3,9 @@
   "version": "0.0.0",
   "private": true,
   "type": "module",
+  "exports": {
+    "./sdk": "./src/sdk/index.ts"
+  },
   "scripts": {
     "typecheck": "tsc --noEmit",
     "build:ui": "vite build --config vite.config.ts",

buyer/scripts/monitor-wallets.ts

@@ -83,6 +83,48 @@ const OPERATOR_SOURCES: OperatorSource[] = [
     keyVar: "SUPPLIER_PRIV_KEY_HEX",
     role: "supplier",
   },
+  {
+    label: "supplier-kimi-2@vector-marketplace",
+    host: "root@91.98.147.172",
+    envPath: "/root/agents-marketplace/supplier/.env.kimi-2",
+    keyVar: "SUPPLIER_PRIV_KEY_HEX",
+    role: "supplier",
+  },
+  {
+    label: "supplier-kimi-3@vector-marketplace",
+    host: "root@91.98.147.172",
+    envPath: "/root/agents-marketplace/supplier/.env.kimi-3",
+    keyVar: "SUPPLIER_PRIV_KEY_HEX",
+    role: "supplier",
+  },
+  {
+    label: "supplier-kimi-4@vector-marketplace",
+    host: "root@91.98.147.172",
+    envPath: "/root/agents-marketplace/supplier/.env.kimi-4",
+    keyVar: "SUPPLIER_PRIV_KEY_HEX",
+    role: "supplier",
+  },
+  {
+    label: "supplier-deepseek-flash-1@vector-marketplace",
+    host: "root@91.98.147.172",
+    envPath: "/root/agents-marketplace/supplier/.env.deepseek-flash-1",
+    keyVar: "SUPPLIER_PRIV_KEY_HEX",
+    role: "supplier",
+  },
+  {
+    label: "supplier-deepseek-flash-2@vector-marketplace",
+    host: "root@91.98.147.172",
+    envPath: "/root/agents-marketplace/supplier/.env.deepseek-flash-2",
+    keyVar: "SUPPLIER_PRIV_KEY_HEX",
+    role: "supplier",
+  },
+  {
+    label: "supplier-deepseek-flash-3@vector-marketplace",
+    host: "root@91.98.147.172",
+    envPath: "/root/agents-marketplace/supplier/.env.deepseek-flash-3",
+    keyVar: "SUPPLIER_PRIV_KEY_HEX",
+    role: "supplier",
+  },
   {
     label: "buyer@open-webui",
     host: "open-webui",

buyer/src/config.ts

@@ -36,6 +36,12 @@
  *                         Defaults to "./data/archive" relative to cwd.
  *                         When unset, archive is disabled (responses are
  *                         not persisted; /v1/responses* return 503).
+ *   GATEWAY_PUBLIC_URL  — Public base URL of the OpenAI-compatible gateway
+ *                         (e.g. https://api.marketplace.vector.apexfusion.org).
+ *                         Injected into the SPA boot block so the "Generate
+ *                         API key" page knows where to POST /signup. When
+ *                         unset, the SPA falls back to deriving "api." +
+ *                         current host.
  */
 
 const HEX64_RE = /^[0-9a-fA-F]{64}$/;
@@ -56,6 +62,7 @@ export interface BuyerConfig {
   password: string;
   sessionSecret: string;
   cookieSecure: boolean;
+  gatewayPublicUrl: string;
 }
 
 function requireField(env: Record<string, string | undefined>, name: string): string {
@@ -141,6 +148,11 @@ export function loadConfig(env: Record<string, string | undefined>): BuyerConfig
     cookieSecure = cookieSecureStr === "1";
   }
 
+  // GATEWAY_PUBLIC_URL — optional. Public base URL of the gateway, surfaced to
+  // the SPA via the boot block (no trailing slash). Empty string means the SPA
+  // derives the URL from its own host ("api." + location.host).
+  const gatewayPublicUrl = (env.GATEWAY_PUBLIC_URL ?? "").trim().replace(/\/+$/, "");
+
   return {
     privKeyHex,
     indexerUrl,
@@ -155,5 +167,6 @@ export function loadConfig(env: Record<string, string | undefined>): BuyerConfig
     password,
     sessionSecret,
     cookieSecure,
+    gatewayPublicUrl,
   };
 }

buyer/src/index.ts

@@ -133,6 +133,7 @@ export async function runMain(env: Record<string, string | undefined>): Promise<
     password: config.password,
     sessionSecret: config.sessionSecret,
     cookieSecure: config.cookieSecure,
+    gatewayPublicUrl: config.gatewayPublicUrl,
     jobStore,
     pdfCaps,
   });

buyer/src/sdk/Marketplace.ts

@@ -80,7 +80,6 @@ import {
   TxConstructionError,
 } from "@marketplace/shared/tx";
 import { decodeAdvertDatum, decodeEscrowDatum, canonicalize } from "@marketplace/shared/cbor";
-import { verifyReceipt } from "@marketplace/shared/receipt";
 import type { AdvertDatum } from "@marketplace/shared/cbor";
 import type {
   SupplierView,
@@ -91,6 +90,7 @@ import type {
   SubmitTtsResult,
   StartChatOptions,
   StartChatResult,
+  ChatSettleMode,
   EndChatOptions,
   EndChatResult,
   AcceptResultOptions,
@@ -823,6 +823,30 @@ export class Marketplace extends EventEmitterBase {
     }
     const advertDatum = decodeAdvertDatum(advertUtxo.datumHex);
 
+    const supplierHttp = new HttpClient({ baseUrl: advertDatum.endpoint_url, fetch: this.fetchImpl });
+
+    // Pre-flight: refuse to lock any funds if the supplier is already serving
+    // another chat. The supplier is single-slot, so a second concurrent escrow
+    // would only 409 at Claim and be left stranded Open with funds locked.
+    // Checking /status first keeps the buyer's funds unlocked. Best-effort: if
+    // /status is unreachable we proceed, and the supplier's Claim still guards
+    // the slot.
+    try {
+      const statusRes = await supplierHttp.getJson("/status");
+      const liveStatus = statusRes.body && typeof statusRes.body === "object"
+        ? (statusRes.body as { status?: string }).status
+        : undefined;
+      if (liveStatus === "working") {
+        throw new SupplierError("supplier_busy", {
+          status: 409,
+          message: "supplier is busy with another chat session",
+        });
+      }
+    } catch (err) {
+      if (err instanceof SupplierError) throw err;
+      /* /status unreachable — proceed; Claim still enforces the single slot */
+    }
+
     const sessionNonce = randomNonce();
     let escrowResult;
     try {
@@ -851,7 +875,6 @@ export class Marketplace extends EventEmitterBase {
       /* mock providers / tests */
     }
 
-    const supplierHttp = new HttpClient({ baseUrl: advertDatum.endpoint_url, fetch: this.fetchImpl });
     let startRes;
     try {
       startRes = await supplierHttp.postJson(
@@ -877,7 +900,13 @@ export class Marketplace extends EventEmitterBase {
     }
 
     this.emitProgress({ type: "chat_started", escrow_ref: escrowRefStr });
-    return { escrowRef: escrowOutputRef, sessionNonce, supplierBaseUrl: advertDatum.endpoint_url };
+    // Ticket-mode suppliers answer {status:"ticket"} (no Claim); anything else
+    // — "claimed" or an older supplier without the field — is full settlement.
+    const startStatus = startRes.body && typeof startRes.body === "object"
+      ? (startRes.body as { status?: string }).status
+      : undefined;
+    const settleMode: ChatSettleMode = startStatus === "ticket" ? "ticket" : "full";
+    return { escrowRef: escrowOutputRef, sessionNonce, supplierBaseUrl: advertDatum.endpoint_url, settleMode };
   }
 
   /**
@@ -886,22 +915,15 @@ export class Marketplace extends EventEmitterBase {
    * Submitted escrow — which is when the user is actually charged.
    */
   async endChat(opts: EndChatOptions): Promise<EndChatResult> {
-    const { escrowRef, sessionNonce, transcript } = opts;
+    const { escrowRef, sessionNonce, transcript, supplierBaseUrl } = opts;
     const escrowRefStr = refToString(escrowRef);
 
-    // Resolve escrow → advert for endpoint_url, supplier_pkh, model, pub key.
-    const escrowUtxo = await this.chain.queryUtxo(escrowRef);
-    if (!escrowUtxo || !escrowUtxo.datumHex) {
-      throw new TxConstructionError("escrow ref not on chain", `no escrow UTxO at ${escrowRefStr}`);
-    }
-    const escrowDatum = decodeEscrowDatum(escrowUtxo.datumHex);
-    const advertUtxo = await this.chain.queryUtxo(escrowDatum.advert_ref);
-    if (!advertUtxo || !advertUtxo.datumHex) {
-      throw new TxConstructionError("advert ref not on chain", "advert UTxO for this escrow is missing");
-    }
-    const advertDatum = decodeAdvertDatum(advertUtxo.datumHex);
-
-    const supplierHttp = new HttpClient({ baseUrl: advertDatum.endpoint_url, fetch: this.fetchImpl });
+    // The original Open escrow UTxO has ALREADY been spent by the supplier's
+    // Claim (Open→Claimed) by the time End runs, so we must NOT queryUtxo it
+    // (that was the cause of the "escrow ref not on chain" 502). Use the
+    // supplier endpoint the buyer-app cached from startChat, and resolve
+    // supplier identity (pkh, model) from /capability for verification.
+    const supplierHttp = new HttpClient({ baseUrl: supplierBaseUrl, fetch: this.fetchImpl });
     let endRes;
     try {
       endRes = await supplierHttp.postJson("/v1/chat/end", {}, { headers: { "X-Escrow-Ref": escrowRefStr } });
@@ -922,18 +944,43 @@ export class Marketplace extends EventEmitterBase {
       });
     }
     const endBody = endRes.body as {
+      status?: string;
+      settle_mode?: string;
       receipt?: import("@marketplace/shared/receipt").Receipt;
       receipt_signature?: string;
       submitted_ref?: string;
     };
+    // Ticket sessions produce no receipt and nothing to Accept — the Open
+    // escrow returns via reclaim after deliver_by. Trusting the supplier's
+    // response is incentive-safe: lying in either direction only forfeits the
+    // supplier's own payout (the buyer's sweeper reclaims unsettled escrows).
+    if (endBody.settle_mode === "ticket") {
+      this.emitProgress({ type: "chat_ended", escrow_ref: escrowRefStr });
+      return { settleMode: "ticket", escrowRef };
+    }
     if (!endBody.receipt || !endBody.receipt_signature) {
       throw new SupplierError("malformed_response", { message: "supplier end response missing receipt" });
     }
     const receipt = endBody.receipt;
     const receiptSignature = endBody.receipt_signature;
 
+    // ── Resolve supplier identity from /capability for verification ───────
+    let capSupplierPkh = "";
+    let capModel = "";
+    try {
+      const capRes = await supplierHttp.getJson("/capability");
+      if (capRes.body && typeof capRes.body === "object") {
+        capSupplierPkh = (capRes.body as { supplier_pkh?: string }).supplier_pkh ?? "";
+        capModel = (capRes.body as { model?: string }).model ?? "";
+      }
+    } catch {
+      /* best-effort; the escrow_ref + prompt_hash + signature checks below,
+         plus the on-chain Accept (which routes funds per the Submitted datum),
+         still hold even if /capability is briefly unavailable */
+    }
+
     // ── Verify receipt ───────────────────────────────────────────────────
-    if (receipt.supplier_pkh !== escrowDatum.supplier_pkh) {
+    if (capSupplierPkh && receipt.supplier_pkh !== capSupplierPkh) {
       throw new ReceiptVerificationError("wrong_supplier");
     }
     if (receipt.escrow_ref !== escrowRefStr) {
@@ -943,7 +990,7 @@ export class Marketplace extends EventEmitterBase {
     if (receipt.prompt_hash !== chatSessionPromptHash({ session_nonce: sessionNonce })) {
       throw new ReceiptVerificationError("prompt_hash_mismatch");
     }
-    if (receipt.model !== advertDatum.model) {
+    if (capModel && receipt.model !== capModel) {
       throw new ReceiptVerificationError("request_spec_hash_mismatch");
     }
     if (typeof receiptSignature !== "string" || !SIG_RE.test(receiptSignature) || receiptSignature === ZERO_SIGNATURE) {
@@ -961,21 +1008,13 @@ export class Marketplace extends EventEmitterBase {
         );
       }
     }
-    // Cryptographic verification via the supplier's published pub key (best-effort).
-    try {
-      const capRes = await supplierHttp.getJson("/capability");
-      const pubKeyHex = capRes.body && typeof capRes.body === "object"
-        ? (capRes.body as { pub_key_hex?: string }).pub_key_hex
-        : undefined;
-      if (typeof pubKeyHex === "string" && /^[0-9a-fA-F]{64}$/.test(pubKeyHex)) {
-        if (!verifyReceipt({ receipt, signature: receiptSignature }, pubKeyHex)) {
-          throw new ReceiptVerificationError("invalid_signature");
-        }
-      }
-    } catch (err) {
-      if (err instanceof ReceiptVerificationError) throw err;
-      /* /capability unreachable — structural verification stands */
-    }
+    // NOTE: cryptographic Ed25519 verifyReceipt is intentionally NOT called
+    // here. It lives in @marketplace/shared/receipt/sign.ts, whose top-level
+    // `import { createHash } from "crypto"` cannot be bundled into the browser
+    // SPA (Vite externalizes `crypto`). The one-off submitPrompt/submitTts
+    // paths take the same structural-only stance (see the M1-E/M1-F note at the
+    // top of this file). The structural checks above + the on-chain
+    // result_receipt_hash commitment are the v1 verification surface.
 
     this.emitProgress({ type: "receipt_verified", escrow_ref: escrowRefStr });
 
@@ -1000,7 +1039,7 @@ export class Marketplace extends EventEmitterBase {
     this.emitProgress({ type: "accept_submitted", escrow_ref: refToString(acceptedRef) });
     this.emitProgress({ type: "chat_ended", escrow_ref: escrowRefStr });
 
-    return { receipt, receiptSignature, escrowRef, acceptedRef };
+    return { settleMode: "full", receipt, receiptSignature, escrowRef, acceptedRef };
   }
 
   // ─── acceptResult / reclaim ───────────────────────────────────────────

buyer/src/sdk/index.ts

@@ -16,6 +16,9 @@ export type {
   AcceptResultOptions,
   ReclaimOptions,
   GetTaskHistoryOptions,
+  ChatSettleMode,
+  StartChatResult,
+  EndChatResult,
 } from "./types.js";
 export { ReceiptVerificationError, IndexerError, SupplierError } from "./types.js";
 export type { TaskHistoryStore } from "./history.js";

buyer/src/sdk/types.ts

@@ -197,6 +197,11 @@ export interface StartChatOptions {
   advertRef: OutputReference;
   payment_lovelace: bigint;
 }
+/** Chain settlement mode a chat session runs under (reported by the supplier
+ * at /v1/chat/start): "full" = Claim/Submit/Accept lifecycle; "ticket" = the
+ * buyer's escrow post is the only chain op (reclaimed after deliver_by). */
+export type ChatSettleMode = "full" | "ticket";
+
 export interface StartChatResult {
   escrowRef: OutputReference;
   /** Random nonce committed into the escrow's session-init prompt_hash. The
@@ -204,6 +209,8 @@ export interface StartChatResult {
   sessionNonce: string;
   /** Supplier endpoint_url, cached by the buyer-app for message routing. */
   supplierBaseUrl: string;
+  /** How the supplier settles this session ("full" when it Claimed). */
+  settleMode: ChatSettleMode;
 }
 
 /**
@@ -213,16 +220,28 @@ export interface StartChatResult {
 export interface EndChatOptions {
   escrowRef: OutputReference;
   sessionNonce: string;
+  /** Supplier endpoint_url cached by the buyer-app from startChat. Required
+   * because the Open escrow UTxO is already spent (Claimed) by End time, so we
+   * resolve the supplier via its cached URL + /capability rather than chain. */
+  supplierBaseUrl: string;
   /** The browser's local transcript mirror, used to verify response_hash. */
   transcript?: import("@marketplace/shared/tx").ChatMessage[];
 }
-export interface EndChatResult {
-  receipt: Receipt;
-  receiptSignature: string;
-  escrowRef: OutputReference;
-  /** The Submitted escrow UTxO that was Accepted. */
-  acceptedRef: OutputReference;
-}
+export type EndChatResult =
+  | {
+      settleMode: "full";
+      receipt: Receipt;
+      receiptSignature: string;
+      escrowRef: OutputReference;
+      /** The Submitted escrow UTxO that was Accepted. */
+      acceptedRef: OutputReference;
+    }
+  | {
+      /** Ticket session: nothing was Submitted/Accepted — no receipt exists.
+       * The Open escrow returns to the buyer via reclaim after deliver_by. */
+      settleMode: "ticket";
+      escrowRef: OutputReference;
+    };
 
 /**
  * AcceptResultOptions — arguments to Marketplace.acceptResult().

buyer/src/server.ts

@@ -109,6 +109,11 @@ export interface AppDeps {
    * brute-force rate-limit window. Defaults to Date.now. Tests use a fake
    * clock to drive expiry and rolling-renewal assertions deterministically. */
   nowMs?: () => number;
+  /** Public base URL of the OpenAI-compatible gateway, injected into the SPA
+   * boot block so the "Generate API key" page can POST cross-origin to
+   * `${gatewayUrl}/signup`. Public, non-secret value. When empty/omitted the
+   * SPA derives "api." + its own host. */
+  gatewayPublicUrl?: string;
   /** PDF book summarizer job registry. When provided, the /v1/pdf-* routes
    * are live; when omitted they respond 503 (feature disabled). Built in
    * runMain from the same marketplace/chain/wallet/archive deps. */
@@ -379,6 +384,37 @@ export function createApp(deps: AppDeps): Express {
     }
   });
 
+  // ── GET /v1/wallet/balance — live buyer-wallet balance from Ogmios.
+  // Sums lovelace across all UTxOs at the buyer's address. The Wallet page
+  // renders this as AP3X (lovelace / 1e6).
+  app.get("/v1/wallet/balance", async (_req: Request, res: Response) => {
+    if (!resolved) {
+      return jsonError(
+        res,
+        503,
+        "service_unavailable",
+        "buyer-app booted without chain deps; /v1/wallet/balance disabled",
+      );
+    }
+    try {
+      const utxos = await resolved.chain.queryUtxosByAddress(resolved.walletKey.address);
+      let lovelace = 0n;
+      for (const u of utxos) lovelace += u.lovelace;
+      return res.status(200).json({
+        address: resolved.walletKey.address,
+        lovelace: lovelace.toString(),
+        utxo_count: utxos.length,
+      });
+    } catch (err) {
+      return jsonError(
+        res,
+        502,
+        "chain_unreachable",
+        err instanceof Error ? err.message : String(err),
+      );
+    }
+  });
+
   // ── /v1/indexer/* — generic GET passthrough to the internal indexer.
   // The SPA's SDK is configured with `indexerUrl = ${origin}/v1/indexer`,
   // so calls like `/suppliers`, `/escrows?buyer=…`, `/capabilities` land
@@ -649,9 +685,11 @@ export function createApp(deps: AppDeps): Express {
   const DEMO_CHAT_MODEL = "moonshotai/kimi-k2.6";
 
   function isChatMessageArray(v: unknown): v is ChatMessage[] {
+    // The free chat demo stays text-only: the `tool` role (added to
+    // ChatMessage for the gateway demo endpoint) is not accepted here.
     return Array.isArray(v) && v.length > 0 && v.every(
       (m) => m && typeof m === "object"
-        && (["system", "user", "assistant"] as const).includes((m as ChatMessage).role)
+        && ["system", "user", "assistant"].includes((m as ChatMessage).role)
         && typeof (m as ChatMessage).content === "string",
     );
   }
@@ -881,11 +919,29 @@ export function createApp(deps: AppDeps): Express {
     const transcript = Array.isArray(body.transcript)
       ? (body.transcript as ChatMessage[])
       : undefined;
+    const state = chatRouteState.get(rawRef);
+    if (!state) {
+      return jsonError(res, 404, "chat_session_not_found",
+        "no active chat session for this escrow (the buyer-app may have restarted); please start a new chat");
+    }
     const m = ESCROW_REF_RE.exec(rawRef)!;
     const escrowRef = { txHash: m[1], index: Number(m[2]) };
     try {
-      const result = await deps.marketplace.endChat({ escrowRef, sessionNonce, transcript });
+      const result = await deps.marketplace.endChat({
+        escrowRef,
+        sessionNonce,
+        transcript,
+        supplierBaseUrl: state.supplierBaseUrl,
+      });
       chatRouteState.delete(rawRef);
+      if (result.settleMode === "ticket") {
+        // Ticket session: no receipt/Accept — funds return via reclaim.
+        return res.status(200).json({
+          status: "ended",
+          escrow_ref: rawRef,
+          settle_mode: "ticket",
+        });
+      }
       return res.status(200).json({
         status: "accepted",
         escrow_ref: rawRef,
@@ -1269,6 +1325,9 @@ export function createApp(deps: AppDeps): Express {
               pubKeyHash: resolved.walletKey.pubKeyHash,
               address: displayAddress,
             },
+            // Public gateway base URL for the "Generate API key" page. Empty
+            // string when unconfigured — the SPA then derives "api." + host.
+            gatewayUrl: deps.gatewayPublicUrl ?? "",
           })};</script>`
         : "";
       const indexWithBoot = cachedTemplate.replace(

buyer/src/ui/App.tsx

@@ -6,6 +6,7 @@
  *   /tasks    → <TaskHistory />
  *   /pending  → <PendingReceipts />     UX-1: buyer-side Accept button
  *   /wallet   → <Wallet />
+ *   /api-keys → <ApiKeys />             self-serve gateway API key generation
  */
 
 import { Routes, Route, Link } from "react-router-dom";
@@ -14,6 +15,7 @@ import TaskHistory from "./pages/TaskHistory.js";
 import Wallet from "./pages/Wallet.js";
 import PendingReceipts from "./pages/PendingReceipts.js";
 import BookSummarizer from "./pages/BookSummarizer.js";
+import ApiKeys from "./pages/ApiKeys.js";
 import { RequireAuth, useAuth } from "./state/AuthContext.js";
 
 function SignOutButton() {
@@ -35,10 +37,13 @@ export default function App() {
       <div className="min-h-screen bg-gray-50 text-gray-900">
         <nav className="bg-white border-b border-gray-200 px-6 py-3 flex items-center gap-6">
           <Link to="/" className="font-medium hover:underline">Dashboard</Link>
-          <Link to="/book" className="font-medium hover:underline">Book Summarizer</Link>
+          {/* Book Summarizer tab hidden for now — the /book route and all PDF
+              summarize code remain intact; restore by re-adding this link:
+          <Link to="/book" className="font-medium hover:underline">Book Summarizer</Link> */}
           <Link to="/tasks" className="font-medium hover:underline">Tasks</Link>
           <Link to="/pending" className="font-medium hover:underline">Pending</Link>
           <Link to="/wallet" className="font-medium hover:underline">Wallet</Link>
+          <Link to="/api-keys" className="font-medium hover:underline">API Keys</Link>
           <SignOutButton />
         </nav>
         <main className="p-6">
@@ -48,6 +53,7 @@ export default function App() {
             <Route path="/tasks" element={<TaskHistory />} />
             <Route path="/pending" element={<PendingReceipts />} />
             <Route path="/wallet" element={<Wallet />} />
+            <Route path="/api-keys" element={<ApiKeys />} />
           </Routes>
         </main>
       </div>

buyer/src/ui/components/ChatForm.tsx

@@ -21,7 +21,7 @@
  *   data: {"type":"error","message":"…"}\n\n
  */
 
-import { useRef, useState } from "react";
+import { useEffect, useRef, useState } from "react";
 import type { OutputReference } from "@marketplace/shared/chain";
 
 export interface ChatFormProps {
@@ -102,8 +102,28 @@ async function streamChat(
   }
 }
 
+/** Animated "Thinking …" placeholder shown while waiting for the model's
+ * first token (the assistant bubble exists but no content has streamed yet). */
+function ThinkingDots(): JSX.Element {
+  return (
+    <span className="inline-flex items-center gap-1 text-gray-500" data-testid="chat-thinking">
+      Thinking
+      <span className="inline-flex items-end gap-0.5 pb-0.5">
+        {[0, 150, 300].map((d) => (
+          <span
+            key={d}
+            className="h-1.5 w-1.5 animate-bounce rounded-full bg-gray-400"
+            style={{ animationDelay: `${d}ms` }}
+          />
+        ))}
+      </span>
+    </span>
+  );
+}
+
 export default function ChatForm({ advertRef, payment_lovelace }: ChatFormProps = {}): JSX.Element {
   const isPaid = advertRef !== undefined && payment_lovelace !== undefined;
+  const advertRefStr = advertRef ? `${advertRef.txHash}#${advertRef.index}` : null;
 
   const [turns, setTurns] = useState<ChatTurn[]>([]);
   const [streaming, setStreaming] = useState<string | null>(null); // in-progress assistant text
@@ -116,11 +136,43 @@ export default function ChatForm({ advertRef, payment_lovelace }: ChatFormProps
   const [starting, setStarting] = useState(false);
   const [ending, setEnding] = useState(false);
   const [charged, setCharged] = useState<string | null>(null);
+  // Live supplier availability (paid mode): null = unknown/checking, true = free, false = busy/offline.
+  const [available, setAvailable] = useState<boolean | null>(null);
   const sessionRef = useRef<Session | null>(null);
   sessionRef.current = session;
 
   const active = isPaid ? session !== null && charged === null : true;
 
+  // Poll the supplier's status while the Start button is showing, so a second
+  // user can't start a chat while one is already active. The supplier is
+  // single-slot (status "working" between Claim and Submit); we disable Start
+  // until it's "free" again. (startChat also does an authoritative pre-flight
+  // /status check, so this is the UX layer over that guard.)
+  useEffect(() => {
+    if (!isPaid || !advertRefStr || session !== null || charged !== null) return;
+    let cancelled = false;
+    const check = async (): Promise<void> => {
+      try {
+        const r = await fetch("/v1/indexer/suppliers?capability_id=llm.chat.v1");
+        if (!r.ok) throw new Error(String(r.status));
+        const rows = (await r.json()) as Array<{ utxo_ref: string; status: string }>;
+        const row = rows.find((x) => x.utxo_ref === advertRefStr);
+        // Unknown (row missing / indexer hiccup) → null, which does NOT hard-block
+        // (the pre-flight check still guards funds); only an explicit non-free
+        // status disables the button.
+        if (!cancelled) setAvailable(row ? row.status === "free" : null);
+      } catch {
+        if (!cancelled) setAvailable(null);
+      }
+    };
+    void check();
+    const id = setInterval(check, 8000);
+    return () => {
+      cancelled = true;
+      clearInterval(id);
+    };
+  }, [isPaid, advertRefStr, session, charged]);
+
   async function startChat(): Promise<void> {
     if (!advertRef || payment_lovelace === undefined) return;
     setStarting(true);
@@ -215,7 +267,18 @@ export default function ChatForm({ advertRef, payment_lovelace }: ChatFormProps
         } catch { /* keep fallback */ }
         throw new Error(msg);
       }
-      setCharged(payment_lovelace !== undefined ? ap3x(payment_lovelace) : "0");
+      let endBody: { settle_mode?: string } = {};
+      try {
+        endBody = (await resp.json()) as { settle_mode?: string };
+      } catch { /* older buyer-app responses stay full-settle */ }
+      // Ticket sessions never charge — the escrow returns via reclaim.
+      setCharged(
+        endBody.settle_mode === "ticket"
+          ? "0 (ticket session — escrow reclaimed)"
+          : payment_lovelace !== undefined
+            ? ap3x(payment_lovelace)
+            : "0",
+      );
     } catch (err) {
       setError(err instanceof Error ? err.message : String(err));
     } finally {
@@ -226,15 +289,26 @@ export default function ChatForm({ advertRef, payment_lovelace }: ChatFormProps
   return (
     <div className="space-y-4 rounded border border-gray-200 bg-white p-4" data-testid="chat-form">
       {isPaid && session === null && (
-        <button
-          type="button"
-          onClick={startChat}
-          disabled={starting}
-          className="rounded bg-blue-600 px-4 py-2 text-sm font-medium text-white hover:bg-blue-700 disabled:bg-gray-400"
-          data-testid="chat-start"
-        >
-          {starting ? "Opening escrow…" : "Start chat"}
-        </button>
+        <div className="space-y-2">
+          <button
+            type="button"
+            onClick={startChat}
+            disabled={starting || available === false}
+            className="rounded bg-blue-600 px-4 py-2 text-sm font-medium text-white hover:bg-blue-700 disabled:bg-gray-400"
+            data-testid="chat-start"
+          >
+            {starting
+              ? "Opening escrow…"
+              : available === false
+                ? "Supplier busy"
+                : "Start chat"}
+          </button>
+          {available === false && (
+            <p className="text-sm text-amber-700" data-testid="chat-busy">
+              Another chat is in progress on this supplier. The button re-enables when it ends.
+            </p>
+          )}
+        </div>
       )}
 
       {(active || streaming !== null || turns.length > 0) && (
@@ -257,7 +331,7 @@ export default function ChatForm({ advertRef, payment_lovelace }: ChatFormProps
             {streaming !== null && (
               <div className="text-left">
                 <span className="inline-block max-w-[85%] whitespace-pre-wrap rounded bg-gray-100 px-3 py-2 text-sm text-gray-900">
-                  {streaming.length > 0 ? streaming : "…"}
+                  {streaming.length > 0 ? streaming : <ThinkingDots />}
                 </span>
               </div>
             )}

buyer/src/ui/components/JobEstimate.tsx

@@ -94,7 +94,7 @@ export default function JobEstimate({
           <dd className="text-right">{est.mapCalls}</dd>
           <dt>Reduce calls</dt>
           <dd className="text-right">{est.reduceCalls}</dd>
-          <dt className="font-medium">Total paid calls</dt>
+          <dt className="font-medium">Total escrowed calls</dt>
           <dd className="text-right font-medium">{est.totalCalls}</dd>
           <dt className="font-medium">Est. max cost</dt>
           <dd className="text-right font-medium">{est.totalAp3x} AP3X</dd>
@@ -126,7 +126,7 @@ export default function JobEstimate({
         disabled={blocked || starting}
         className="rounded bg-indigo-600 px-4 py-2 text-sm font-medium text-white hover:bg-indigo-700 disabled:bg-gray-400"
       >
-        {starting ? "Starting…" : `Proceed & pay (~${est.totalAp3x} AP3X)`}
+        {starting ? "Starting…" : `Proceed (locks ~${est.totalAp3x} AP3X in escrow)`}
       </button>
     </div>
   );

buyer/src/ui/components/PdfUploadForm.tsx

@@ -50,7 +50,7 @@ export default function PdfUploadForm({ onUploaded }: { onUploaded: (info: Uploa
   return (
     <form onSubmit={handleSubmit} className="space-y-4">
       <p className="text-sm text-gray-600">
-        Upload a text-based PDF book. The buyer will chunk it and pay marketplace
+        Upload a text-based PDF book. The buyer will chunk it and commission marketplace
         suppliers to summarize each chunk, then synthesize a full-book summary.
       </p>
       <input

buyer/src/ui/gateway.ts

@@ -0,0 +1,32 @@
+/**
+ * buyer/src/ui/gateway.ts — resolve the OpenAI-compatible gateway base URL the
+ * SPA should call for the "Generate API key" page.
+ *
+ * Resolution order:
+ *   1. window.__BUYER_BOOT__.gatewayUrl — injected by the buyer server from the
+ *      GATEWAY_PUBLIC_URL env (the configured value). Present on any page load
+ *      made while the buyer_session cookie is valid.
+ *   2. Derived "api." + current host — the deploy convention is exactly
+ *      api.<buyer-host> (marketplace.… → api.marketplace.…). This covers the
+ *      gap right after a fresh login, when the SPA flips auth state WITHOUT a
+ *      page reload so the boot block (which is only injected into
+ *      server-rendered HTML) hasn't been re-fetched yet.
+ *
+ * The result never has a trailing slash.
+ */
+
+interface BuyerBootMaybeGateway {
+  gatewayUrl?: string;
+}
+
+function stripTrailingSlashes(url: string): string {
+  return url.replace(/\/+$/, "");
+}
+
+export function resolveGatewayUrl(): string {
+  const boot = (window as unknown as { __BUYER_BOOT__?: BuyerBootMaybeGateway })
+    .__BUYER_BOOT__;
+  const configured = boot?.gatewayUrl?.trim();
+  if (configured) return stripTrailingSlashes(configured);
+  return `${window.location.protocol}//api.${window.location.host}`;
+}

buyer/src/ui/pages/ApiKeys.tsx

@@ -0,0 +1,205 @@
+/**
+ * buyer/src/ui/pages/ApiKeys.tsx — self-serve "Generate API key" page.
+ *
+ * Mints a custodial gateway API key by POSTing directly to the gateway's
+ * public /signup endpoint (cross-origin; the gateway CORS-allows this origin).
+ * The raw key is shown ONCE — it is never stored server-side in retrievable
+ * form, so it cannot be listed or recovered later. The page also surfaces the
+ * funding deposit address and a ready-to-paste usage snippet.
+ *
+ * Access is gated by the SPA's existing operator login (this page only renders
+ * inside <RequireAuth>). The gateway /signup itself stays public + IP
+ * rate-limited; per-user accounts are a later feature.
+ */
+
+import { useState } from "react";
+import { resolveGatewayUrl } from "../gateway.js";
+
+interface SignupResult {
+  api_key: string;
+  key_prefix: string;
+  deposit_address: string;
+}
+
+/** Pull a human-readable message out of whatever error shape the gateway
+ * returns (OpenAI `{error:{message}}`, plain `{error|message}`, or neither). */
+function errorMessage(body: unknown, status: number, statusText: string): string {
+  if (body && typeof body === "object") {
+    const b = body as Record<string, unknown>;
+    const err = b.error;
+    if (err && typeof err === "object" && typeof (err as Record<string, unknown>).message === "string") {
+      return (err as Record<string, string>).message;
+    }
+    if (typeof err === "string") return err;
+    if (typeof b.message === "string") return b.message;
+  }
+  return `${status} ${statusText}`.trim() || "request failed";
+}
+
+function CopyButton({ value, label }: { value: string; label?: string }) {
+  const [copied, setCopied] = useState(false);
+  return (
+    <button
+      type="button"
+      onClick={() => {
+        void navigator.clipboard
+          ?.writeText(value)
+          .then(() => {
+            setCopied(true);
+            setTimeout(() => setCopied(false), 1500);
+          })
+          .catch(() => {
+            /* clipboard blocked (insecure context / permissions) — no-op */
+          });
+      }}
+      className="rounded border border-gray-300 px-2 py-0.5 text-xs text-gray-600 hover:bg-gray-50"
+    >
+      {copied ? "Copied!" : (label ?? "Copy")}
+    </button>
+  );
+}
+
+export default function ApiKeys() {
+  const [label, setLabel] = useState("");
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [result, setResult] = useState<SignupResult | null>(null);
+
+  const gatewayUrl = resolveGatewayUrl();
+  const baseUrl = `${gatewayUrl}/openai/v1`;
+
+  async function generate() {
+    setLoading(true);
+    setError(null);
+    setResult(null);
+    try {
+      const res = await fetch(`${gatewayUrl}/signup`, {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(label.trim() ? { label: label.trim() } : {}),
+      });
+      const body = (await res.json().catch(() => null)) as unknown;
+      if (!res.ok) {
+        throw new Error(errorMessage(body, res.status, res.statusText));
+      }
+      const r = body as Partial<SignupResult> | null;
+      if (!r || typeof r.api_key !== "string" || typeof r.deposit_address !== "string") {
+        throw new Error("unexpected response from gateway");
+      }
+      setResult({
+        api_key: r.api_key,
+        key_prefix: r.key_prefix ?? r.api_key.slice(0, 12),
+        deposit_address: r.deposit_address,
+      });
+    } catch (e) {
+      setError(e instanceof Error ? e.message : "could not reach the gateway");
+    } finally {
+      setLoading(false);
+    }
+  }
+
+  const curlSnippet =
+    result === null
+      ? ""
+      : [
+          `curl ${baseUrl}/chat/completions \\`,
+          `  -H "Authorization: Bearer ${result.api_key}" \\`,
+          `  -H "Content-Type: application/json" \\`,
+          `  -d '{"model": "<model>", "messages": [{"role": "user", "content": "Hello"}]}'`,
+        ].join("\n");
+
+  return (
+    <div className="max-w-3xl space-y-6">
+      <div className="space-y-1">
+        <h1 className="text-2xl font-semibold">API Keys</h1>
+        <p className="text-sm text-gray-600">
+          Generate an OpenAI-compatible API key for the marketplace gateway. Each key has its own
+          gateway-managed wallet (the gateway holds this wallet's key) - fund its deposit address with AP3X, then point any OpenAI SDK at{" "}
+          <code className="font-mono text-xs">{baseUrl}</code>.
+        </p>
+      </div>
+
+      <div className="rounded-lg border border-gray-200 bg-white p-4 space-y-3">
+        <label className="block text-sm font-medium text-gray-700">
+          Label <span className="font-normal text-gray-400">(optional)</span>
+          <input
+            type="text"
+            value={label}
+            onChange={(e) => setLabel(e.target.value)}
+            placeholder="e.g. my-laptop"
+            maxLength={120}
+            disabled={loading}
+            className="mt-1 block w-full rounded border border-gray-300 px-3 py-2 text-sm focus:border-gray-400 focus:outline-none disabled:opacity-50"
+          />
+        </label>
+        <button
+          type="button"
+          onClick={() => void generate()}
+          disabled={loading}
+          className="rounded bg-gray-900 px-4 py-2 text-sm font-medium text-white hover:bg-gray-700 disabled:opacity-50"
+          data-testid="generate-api-key"
+        >
+          {loading ? "Generating…" : "Generate API key"}
+        </button>
+        {error !== null && (
+          <p className="text-sm text-red-600" data-testid="api-key-error">
+            {error}
+          </p>
+        )}
+      </div>
+
+      {result !== null && (
+        <div className="space-y-4 rounded-lg border border-amber-300 bg-amber-50 p-4" data-testid="api-key-result">
+          <div className="rounded border border-amber-400 bg-amber-100 px-3 py-2 text-sm text-amber-900">
+            Copy your API key now — it is shown <strong>only once</strong> and cannot be recovered. If you
+            lose it, generate a new one.
+          </div>
+
+          <div>
+            <div className="flex items-center justify-between">
+              <span className="text-sm font-medium text-gray-700">API key</span>
+              <CopyButton value={result.api_key} />
+            </div>
+            <code className="mt-1 block break-all rounded bg-white px-3 py-2 font-mono text-sm">
+              {result.api_key}
+            </code>
+          </div>
+
+          <div>
+            <div className="flex items-center justify-between">
+              <span className="text-sm font-medium text-gray-700">Deposit address (fund with AP3X)</span>
+              <CopyButton value={result.deposit_address} />
+            </div>
+            <code className="mt-1 block break-all rounded bg-white px-3 py-2 font-mono text-sm">
+              {result.deposit_address}
+            </code>
+          </div>
+
+          <div>
+            <div className="flex items-center justify-between">
+              <span className="text-sm font-medium text-gray-700">Base URL</span>
+              <CopyButton value={baseUrl} />
+            </div>
+            <code className="mt-1 block break-all rounded bg-white px-3 py-2 font-mono text-sm">
+              {baseUrl}
+            </code>
+          </div>
+
+          <div>
+            <div className="flex items-center justify-between">
+              <span className="text-sm font-medium text-gray-700">Quick start</span>
+              <CopyButton value={curlSnippet} />
+            </div>
+            <pre className="mt-1 overflow-x-auto rounded bg-gray-900 px-3 py-2 font-mono text-xs text-gray-100">
+              {curlSnippet}
+            </pre>
+            <p className="mt-1 text-xs text-gray-500">
+              Replace <code className="font-mono">&lt;model&gt;</code> with a model from{" "}
+              <code className="font-mono">{baseUrl}/models</code>.
+            </p>
+          </div>
+        </div>
+      )}
+    </div>
+  );
+}

buyer/src/ui/pages/BookSummarizer.tsx

@@ -152,7 +152,7 @@ export default function BookSummarizer() {
       <div>
         <h1 className="text-2xl font-semibold">Book Summarizer</h1>
         <p className="mt-1 text-sm text-gray-500">
-          Upload a PDF → pay suppliers to summarize each chunk → get a full-book summary.
+          Upload a PDF → commission suppliers to summarize each chunk → get a full-book summary.
           Jobs keep running if you navigate away; reopen them below.
         </p>
       </div>

buyer/src/ui/pages/PendingReceipts.tsx

@@ -1,6 +1,6 @@
 /**
  * buyer/src/ui/pages/PendingReceipts.tsx — list of currently-Submitted escrows
- * for this buyer, with an "Accept & Pay" action per row.
+ * for this buyer, with an "Accept & Settle" action per row.
  *
  * Data flow:
  *   GET /v1/pending-receipts → buyer-app server proxies indexer /escrows?buyer=<pkh>
@@ -190,7 +190,7 @@ export default function PendingReceipts() {
               <th className="px-2 py-2">Submitted</th>
               <th className="px-2 py-2">Supplier</th>
               <th className="px-2 py-2">Capability</th>
-              <th className="px-2 py-2">Payment</th>
+              <th className="px-2 py-2">Escrowed</th>
               <th className="px-2 py-2">Window left</th>
               <th className="px-2 py-2">Action</th>
             </tr>
@@ -254,7 +254,7 @@ export default function PendingReceipts() {
                               : "bg-indigo-600 text-white hover:bg-indigo-700")
                         }
                       >
-                        {isAccepting ? "accepting…" : expired ? "expired" : "Accept & Pay"}
+                        {isAccepting ? "accepting…" : expired ? "expired" : "Accept & Settle"}
                       </button>
                     )}
                   </td>

buyer/src/ui/pages/TaskHistory.tsx

@@ -304,7 +304,7 @@ function LifecycleCard({ lc }: { lc: Lifecycle }): JSX.Element {
           </>
         )}
         <span className="text-gray-500">·</span>
-        <span>{fmtAda(lc.payment_lovelace)} payment</span>
+        <span>{fmtAda(lc.payment_lovelace)} escrowed</span>
         <span className="text-gray-500">·</span>
         <span>{fmtAda(lc.buyer_bond_lovelace)} bond</span>
         <span className="text-gray-500">·</span>

buyer/src/ui/pages/Wallet.tsx

@@ -1,16 +1,89 @@
 /**
- * buyer/src/ui/pages/Wallet.tsx — wallet address + balance view.
+ * buyer/src/ui/pages/Wallet.tsx — wallet address + live balance view.
+ *
+ * Balance is fetched from /v1/wallet/balance, which sums the buyer wallet's
+ * UTxOs live from Ogmios, and rendered as AP3X (lovelace / 1e6).
  */
 
+import { useEffect, useState } from "react";
 import { useMarketplace } from "../state/MarketplaceContext.js";
 
+function formatAp3x(lovelace: string): string {
+  return (Number(lovelace) / 1e6).toLocaleString(undefined, {
+    minimumFractionDigits: 2,
+    maximumFractionDigits: 6,
+  });
+}
+
 export default function Wallet() {
   const marketplace = useMarketplace();
   const walletKey = marketplace.getWalletKey();
+
+  const [lovelace, setLovelace] = useState<string | null>(null);
+  const [utxoCount, setUtxoCount] = useState<number | null>(null);
+  const [error, setError] = useState<string | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [reloadKey, setReloadKey] = useState(0);
+
+  useEffect(() => {
+    let cancelled = false;
+    setLoading(true);
+    setError(null);
+    fetch("/v1/wallet/balance")
+      .then(async (r) => {
+        if (!r.ok) {
+          const j = (await r.json().catch(() => ({}))) as { message?: string; error?: string };
+          throw new Error(j.message ?? j.error ?? `${r.status} ${r.statusText}`);
+        }
+        return r.json() as Promise<{ lovelace: string; utxo_count: number }>;
+      })
+      .then((j) => {
+        if (!cancelled) {
+          setLovelace(j.lovelace);
+          setUtxoCount(j.utxo_count);
+        }
+      })
+      .catch((e: Error) => {
+        if (!cancelled) setError(e.message);
+      })
+      .finally(() => {
+        if (!cancelled) setLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [reloadKey]);
+
   return (
     <div className="space-y-4">
       <h1 className="text-2xl font-semibold">Wallet</h1>
       <dl className="space-y-2">
+        <div>
+          <dt className="text-sm text-gray-500">Balance</dt>
+          <dd className="flex items-baseline gap-3" data-testid="wallet-balance">
+            {loading ? (
+              <span className="text-gray-400">Loading…</span>
+            ) : error ? (
+              <span className="text-sm text-red-600">{error}</span>
+            ) : (
+              <>
+                <span className="text-2xl font-semibold">{formatAp3x(lovelace ?? "0")} AP3X</span>
+                {utxoCount !== null && (
+                  <span className="text-xs text-gray-400">({utxoCount} UTxO{utxoCount === 1 ? "" : "s"})</span>
+                )}
+              </>
+            )}
+            <button
+              type="button"
+              onClick={() => setReloadKey((k) => k + 1)}
+              disabled={loading}
+              className="ml-2 rounded border border-gray-300 px-2 py-0.5 text-xs text-gray-600 hover:bg-gray-50 disabled:opacity-50"
+              data-testid="wallet-balance-refresh"
+            >
+              Refresh
+            </button>
+          </dd>
+        </div>
         <div>
           <dt className="text-sm text-gray-500">Address</dt>
           <dd className="font-mono text-sm break-all">{walletKey.address}</dd>

deploy/mainnet/docker-compose.buyer.yml

@@ -21,10 +21,19 @@ services:
     environment:
       INDEXER_URL: http://marketplace-mainnet-indexer:8090
       BUYER_PORT: "8070"
+      # PiperTTS demo (Path B): direct-proxy target for /v1/synth-speech. Piper is
+      # private on marketplace-mainnet-net (no public host), so use internal DNS.
+      # Without this the demo TTS tile 503s ("booted without TTS_PIPER_BASE_URL").
+      TTS_PIPER_BASE_URL: http://marketplace-mainnet-tts-piper:8000
       # Pin the archive dir so it lands on the persistent volume below — keeps
       # the response archive + PDF job store (past summaries) across container
       # recreation/redeploys.
       ARCHIVE_DIR: /repo/data/archive
+      # Public base URL of the OpenAI gateway, surfaced to the SPA boot block so
+      # the "API Keys" page can POST cross-origin to ${gatewayUrl}/signup. The
+      # gateway must CORS-allow https://marketplace.vector.apexfusion.org (see
+      # GATEWAY_CORS_ORIGINS in docker-compose.gateway.yml).
+      GATEWAY_PUBLIC_URL: https://api.marketplace.vector.apexfusion.org
       # NETWORK_ID intentionally not pinned — see supplier compose comment.
     volumes:
       - buyer-mainnet-archive:/repo/data/archive

deploy/mainnet/docker-compose.gateway.yml

@@ -0,0 +1,90 @@
+# deploy/mainnet/docker-compose.gateway.yml — OpenAI-compatible Gateway — MAINNET
+#
+# Multi-tenant, custodial OpenAI gateway. Each API key is its own buyer wallet;
+# every request posts an on-chain escrow from that user's wallet. See docs/gateway.md.
+#
+# Secrets live in gateway/.env (NOT committed):
+#   GATEWAY_MASTER_KEY=<openssl rand -hex 32>   # losing this locks ALL user funds
+# Back up BOTH gateway/.env (the master key) AND the gateway-mainnet-data volume
+# (the gateway.db holds every user's encrypted wallet key + usage).
+
+name: marketplace-mainnet-gateway
+
+services:
+  gateway:
+    build:
+      context: ../..
+      dockerfile: gateway/Dockerfile
+    container_name: marketplace-mainnet-gateway
+    restart: unless-stopped
+    env_file:
+      - path: ../../gateway/.env
+        required: true
+    environment:
+      INDEXER_URL: http://marketplace-mainnet-indexer:8090
+      OGMIOS_URL: https://ogmios.vector.mainnet.apexfusion.org
+      LIVE_CHAIN: "1"
+      NETWORK_ID: "1"
+      GATEWAY_PORT: "8080"
+      GATEWAY_DB_DIR: /repo/data/gateway
+      # Mainnet chain genesis (slot↔wallclock). MUST match buyer/supplier or
+      # PostEscrow validity bounds land ~51 days off and Ogmios rejects (code 3118).
+      VECTOR_ZERO_TIME_MS: "1756485600000"
+      # On-chain reference-script UTxOs (escrow spending validator) used by
+      # Accept/Reclaim/Submit. Same values the buyer/suppliers use on mainnet.
+      ESCROW_REF_UTXO: c8d84c6d67ec67a1efe5e9c6c06d53020e05d1bb96d1c55ecb1eb7d5010c4d54#0
+      ADVERT_REF_UTXO: c8d84c6d67ec67a1efe5e9c6c06d53020e05d1bb96d1c55ecb1eb7d5010c4d54#1
+      # Browser Origins allowed to call the gateway cross-origin. The buyer
+      # frontend's "API Keys" page (served from marketplace.vector…) POSTs to
+      # /signup here. Comma-separated; empty disables CORS entirely.
+      GATEWAY_CORS_ORIGINS: https://marketplace.vector.apexfusion.org
+      # Ticket mode: the escrow post at session open is the only chain op;
+      # the sweeper reclaims Open escrows after deliver_by. Must match the
+      # kimi-chat suppliers' CHAT_SETTLE_MODE.
+      CHAT_SETTLE_MODE: ticket
+      # Demo janitor closes idle sessions BEFORE the suppliers' 15 min
+      # CHAT_IDLE_TIMEOUT_MS backstop.
+      DEMO_SESSION_IDLE_MS: "600000"
+    volumes:
+      - gateway-mainnet-data:/repo/data/gateway
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      # This host is NOT Cloudflare-proxied: traefik terminates TLS itself with
+      # a Let's Encrypt cert (resolver defined in /root/traefik/traefik.yml on
+      # the box). The :80 router only redirects; ACME HTTP-01 challenges are
+      # answered by traefik before the redirect applies.
+      - "traefik.http.routers.mp-gateway-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-gateway-mainnet.rule=Host(`api.marketplace.vector.apexfusion.org`)"
+      - "traefik.http.routers.mp-gateway-mainnet.middlewares=mp-gateway-mainnet-https"
+      - "traefik.http.middlewares.mp-gateway-mainnet-https.redirectscheme.scheme=https"
+      - "traefik.http.middlewares.mp-gateway-mainnet-https.redirectscheme.permanent=true"
+      - "traefik.http.routers.mp-gateway-mainnet-tls.entrypoints=websecure"
+      - "traefik.http.routers.mp-gateway-mainnet-tls.rule=Host(`api.marketplace.vector.apexfusion.org`)"
+      - "traefik.http.routers.mp-gateway-mainnet-tls.tls.certresolver=letsencrypt"
+      - "traefik.http.services.mp-gateway-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net
+
+volumes:
+  gateway-mainnet-data:

deploy/mainnet/docker-compose.supplier-deepseek-flash-1.yml

@@ -0,0 +1,65 @@
+# deploy/mainnet/docker-compose.supplier-deepseek-flash-1.yml — Supplier — MAINNET (OpenRouter / DeepSeek V4 Flash #1)
+#
+# Parallel-capacity supplier for deepseek/deepseek-v4-flash via OpenRouter's
+# OpenAI-compatible API. Same shape as the kimi replicas; distinct only in
+# instance name, container, env file, Traefik host/router, and advert model.
+# Shares the same OpenRouter API key as the kimi suppliers (accepted ceiling;
+# supplier has no 429/backoff). Advert caps: max_output_tokens=262144,
+# max_processing_ms=3600000; OPENAI_TIMEOUT_MS matched.
+#
+# Pre-flight:
+#   1. DNS (proxied): mp-suppliers-deepseek-flash-1.vector.apexfusion.org → host
+#   2. supplier/.env.deepseek-flash-1 on host (chmod 600): SUPPLIER_PRIV_KEY_HEX,
+#        OPENAI_API_KEY, OGMIOS_URL, NETWORK_ID=1, VECTOR_ZERO_TIME_MS,
+#        ESCROW_REF_UTXO, ADVERT_REF_UTXO, ADVERT_REF, LIVE_CHAIN=1
+#   3. Networks marketplace-mainnet-net + traefik-net already exist.
+
+name: marketplace-mainnet-supplier-deepseek-flash-1
+
+services:
+  supplier:
+    build:
+      context: ../..
+      dockerfile: supplier/Dockerfile
+    container_name: marketplace-mainnet-supplier-deepseek-flash-1
+    restart: unless-stopped
+    env_file:
+      - path: ../../supplier/.env.deepseek-flash-1
+        required: false
+    environment:
+      LLM_BACKEND: openai
+      # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
+      OPENAI_BASE_URL: https://openrouter.ai/api
+      # Matches the advert's max_processing_ms=3600000 (60 min).
+      OPENAI_TIMEOUT_MS: "3600000"
+      PORT: "8080"
+      LIVE_CHAIN: "1"
+      # NETWORK_ID and OGMIOS_URL come from supplier/.env.deepseek-flash-1.
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      - "traefik.http.routers.mp-suppliers-deepseek-flash-1-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-suppliers-deepseek-flash-1-mainnet.rule=Host(`mp-suppliers-deepseek-flash-1.vector.apexfusion.org`)"
+      - "traefik.http.services.mp-suppliers-deepseek-flash-1-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net

deploy/mainnet/docker-compose.supplier-deepseek-flash-2.yml

@@ -0,0 +1,65 @@
+# deploy/mainnet/docker-compose.supplier-deepseek-flash-2.yml — Supplier — MAINNET (OpenRouter / DeepSeek V4 Flash #2)
+#
+# Parallel-capacity supplier for deepseek/deepseek-v4-flash via OpenRouter's
+# OpenAI-compatible API. Same shape as the kimi replicas; distinct only in
+# instance name, container, env file, Traefik host/router, and advert model.
+# Shares the same OpenRouter API key as the kimi suppliers (accepted ceiling;
+# supplier has no 429/backoff). Advert caps: max_output_tokens=262144,
+# max_processing_ms=3600000; OPENAI_TIMEOUT_MS matched.
+#
+# Pre-flight:
+#   1. DNS (proxied): mp-suppliers-deepseek-flash-2.vector.apexfusion.org → host
+#   2. supplier/.env.deepseek-flash-2 on host (chmod 600): SUPPLIER_PRIV_KEY_HEX,
+#        OPENAI_API_KEY, OGMIOS_URL, NETWORK_ID=1, VECTOR_ZERO_TIME_MS,
+#        ESCROW_REF_UTXO, ADVERT_REF_UTXO, ADVERT_REF, LIVE_CHAIN=1
+#   3. Networks marketplace-mainnet-net + traefik-net already exist.
+
+name: marketplace-mainnet-supplier-deepseek-flash-2
+
+services:
+  supplier:
+    build:
+      context: ../..
+      dockerfile: supplier/Dockerfile
+    container_name: marketplace-mainnet-supplier-deepseek-flash-2
+    restart: unless-stopped
+    env_file:
+      - path: ../../supplier/.env.deepseek-flash-2
+        required: false
+    environment:
+      LLM_BACKEND: openai
+      # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
+      OPENAI_BASE_URL: https://openrouter.ai/api
+      # Matches the advert's max_processing_ms=3600000 (60 min).
+      OPENAI_TIMEOUT_MS: "3600000"
+      PORT: "8080"
+      LIVE_CHAIN: "1"
+      # NETWORK_ID and OGMIOS_URL come from supplier/.env.deepseek-flash-2.
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      - "traefik.http.routers.mp-suppliers-deepseek-flash-2-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-suppliers-deepseek-flash-2-mainnet.rule=Host(`mp-suppliers-deepseek-flash-2.vector.apexfusion.org`)"
+      - "traefik.http.services.mp-suppliers-deepseek-flash-2-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net

deploy/mainnet/docker-compose.supplier-deepseek-flash-3.yml

@@ -0,0 +1,65 @@
+# deploy/mainnet/docker-compose.supplier-deepseek-flash-3.yml — Supplier — MAINNET (OpenRouter / DeepSeek V4 Flash #3)
+#
+# Parallel-capacity supplier for deepseek/deepseek-v4-flash via OpenRouter's
+# OpenAI-compatible API. Same shape as the kimi replicas; distinct only in
+# instance name, container, env file, Traefik host/router, and advert model.
+# Shares the same OpenRouter API key as the kimi suppliers (accepted ceiling;
+# supplier has no 429/backoff). Advert caps: max_output_tokens=262144,
+# max_processing_ms=3600000; OPENAI_TIMEOUT_MS matched.
+#
+# Pre-flight:
+#   1. DNS (proxied): mp-suppliers-deepseek-flash-3.vector.apexfusion.org → host
+#   2. supplier/.env.deepseek-flash-3 on host (chmod 600): SUPPLIER_PRIV_KEY_HEX,
+#        OPENAI_API_KEY, OGMIOS_URL, NETWORK_ID=1, VECTOR_ZERO_TIME_MS,
+#        ESCROW_REF_UTXO, ADVERT_REF_UTXO, ADVERT_REF, LIVE_CHAIN=1
+#   3. Networks marketplace-mainnet-net + traefik-net already exist.
+
+name: marketplace-mainnet-supplier-deepseek-flash-3
+
+services:
+  supplier:
+    build:
+      context: ../..
+      dockerfile: supplier/Dockerfile
+    container_name: marketplace-mainnet-supplier-deepseek-flash-3
+    restart: unless-stopped
+    env_file:
+      - path: ../../supplier/.env.deepseek-flash-3
+        required: false
+    environment:
+      LLM_BACKEND: openai
+      # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
+      OPENAI_BASE_URL: https://openrouter.ai/api
+      # Matches the advert's max_processing_ms=3600000 (60 min).
+      OPENAI_TIMEOUT_MS: "3600000"
+      PORT: "8080"
+      LIVE_CHAIN: "1"
+      # NETWORK_ID and OGMIOS_URL come from supplier/.env.deepseek-flash-3.
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      - "traefik.http.routers.mp-suppliers-deepseek-flash-3-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-suppliers-deepseek-flash-3-mainnet.rule=Host(`mp-suppliers-deepseek-flash-3.vector.apexfusion.org`)"
+      - "traefik.http.services.mp-suppliers-deepseek-flash-3-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net

deploy/mainnet/docker-compose.supplier-ds-flash-chat-1.yml

@@ -0,0 +1,74 @@
+# deploy/mainnet/docker-compose.supplier-ds-flash-chat-1.yml — Supplier — MAINNET
+#   (OpenRouter / deepseek-v4-flash — MULTI-TURN CHAT capability `llm.chat.v1`, REPLICA 1)
+#
+# Chat-session sibling of the deepseek-flash one-off suppliers. Same OpenRouter
+# backend (deepseek/deepseek-v4-flash) but CAPABILITY_KIND=chat-session so it
+# mounts /v1/chat/{start,message,end}. Ticket settle mode (matches the mainnet
+# gateway): the buyer's Open escrow post is the only chain op; the supplier
+# never Claims/Submits; the gateway sweeper reclaims after deliver_by.
+#
+# Pre-flight:
+#   1. DNS A-record: mp-suppliers-ds-flash-chat-1.vector.apexfusion.org -> host IP
+#   2. New supplier wallet (gen-keypair), funded (advert post + fee float).
+#   3. Post a fresh llm.chat.v1 advert for this wallet:
+#        --capability-id llm.chat.v1 --model deepseek/deepseek-v4-flash
+#        --max-processing-ms 1800000 --price-lovelace 200000
+#   4. supplier/.env.ds-flash-chat-1 written on host (chmod 600) with at least:
+#        SUPPLIER_PRIV_KEY_HEX, OPENAI_API_KEY, OGMIOS_URL, NETWORK_ID=1,
+#        VECTOR_ZERO_TIME_MS, ESCROW_REF_UTXO, ADVERT_REF_UTXO, ADVERT_REF,
+#        LIVE_CHAIN=1, OPENAI_REASONING=off, OPENAI_MAX_TOKENS=131072
+
+name: marketplace-mainnet-supplier-ds-flash-chat-1
+
+services:
+  supplier:
+    build:
+      context: ../..
+      dockerfile: supplier/Dockerfile
+    container_name: marketplace-mainnet-supplier-ds-flash-chat-1
+    restart: unless-stopped
+    env_file:
+      - path: ../../supplier/.env.ds-flash-chat-1
+        required: false
+    environment:
+      # Multi-turn chat session capability (mounts /v1/chat/{start,message,end}).
+      CAPABILITY_KIND: chat-session
+      LLM_BACKEND: openai
+      # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
+      OPENAI_BASE_URL: https://openrouter.ai/api
+      OPENAI_TIMEOUT_MS: "300000"
+      CHAT_IDLE_TIMEOUT_MS: "900000"
+      CHAT_SETTLE_MODE: ticket
+      MAX_CHAT_SESSIONS: "8"
+      PORT: "8080"
+      # Enable LiveOgmiosProvider so wallet-health/consolidate can broadcast.
+      LIVE_CHAIN: "1"
+      # NETWORK_ID and OGMIOS_URL come from supplier/.env.ds-flash-chat-1.
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      - "traefik.http.routers.mp-suppliers-ds-flash-chat-1-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-suppliers-ds-flash-chat-1-mainnet.rule=Host(`mp-suppliers-ds-flash-chat-1.vector.apexfusion.org`)"
+      - "traefik.http.services.mp-suppliers-ds-flash-chat-1-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net

deploy/mainnet/docker-compose.supplier-ds-flash-chat-2.yml

@@ -0,0 +1,74 @@
+# deploy/mainnet/docker-compose.supplier-ds-flash-chat-2.yml — Supplier — MAINNET
+#   (OpenRouter / deepseek-v4-flash — MULTI-TURN CHAT capability `llm.chat.v1`, REPLICA 2)
+#
+# Chat-session sibling of the deepseek-flash one-off suppliers. Same OpenRouter
+# backend (deepseek/deepseek-v4-flash) but CAPABILITY_KIND=chat-session so it
+# mounts /v1/chat/{start,message,end}. Ticket settle mode (matches the mainnet
+# gateway): the buyer's Open escrow post is the only chain op; the supplier
+# never Claims/Submits; the gateway sweeper reclaims after deliver_by.
+#
+# Pre-flight:
+#   1. DNS A-record: mp-suppliers-ds-flash-chat-2.vector.apexfusion.org -> host IP
+#   2. New supplier wallet (gen-keypair), funded (advert post + fee float).
+#   3. Post a fresh llm.chat.v1 advert for this wallet:
+#        --capability-id llm.chat.v1 --model deepseek/deepseek-v4-flash
+#        --max-processing-ms 1800000 --price-lovelace 200000
+#   4. supplier/.env.ds-flash-chat-2 written on host (chmod 600) with at least:
+#        SUPPLIER_PRIV_KEY_HEX, OPENAI_API_KEY, OGMIOS_URL, NETWORK_ID=1,
+#        VECTOR_ZERO_TIME_MS, ESCROW_REF_UTXO, ADVERT_REF_UTXO, ADVERT_REF,
+#        LIVE_CHAIN=1, OPENAI_REASONING=off, OPENAI_MAX_TOKENS=131072
+
+name: marketplace-mainnet-supplier-ds-flash-chat-2
+
+services:
+  supplier:
+    build:
+      context: ../..
+      dockerfile: supplier/Dockerfile
+    container_name: marketplace-mainnet-supplier-ds-flash-chat-2
+    restart: unless-stopped
+    env_file:
+      - path: ../../supplier/.env.ds-flash-chat-2
+        required: false
+    environment:
+      # Multi-turn chat session capability (mounts /v1/chat/{start,message,end}).
+      CAPABILITY_KIND: chat-session
+      LLM_BACKEND: openai
+      # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
+      OPENAI_BASE_URL: https://openrouter.ai/api
+      OPENAI_TIMEOUT_MS: "300000"
+      CHAT_IDLE_TIMEOUT_MS: "900000"
+      CHAT_SETTLE_MODE: ticket
+      MAX_CHAT_SESSIONS: "8"
+      PORT: "8080"
+      # Enable LiveOgmiosProvider so wallet-health/consolidate can broadcast.
+      LIVE_CHAIN: "1"
+      # NETWORK_ID and OGMIOS_URL come from supplier/.env.ds-flash-chat-2.
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      - "traefik.http.routers.mp-suppliers-ds-flash-chat-2-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-suppliers-ds-flash-chat-2-mainnet.rule=Host(`mp-suppliers-ds-flash-chat-2.vector.apexfusion.org`)"
+      - "traefik.http.services.mp-suppliers-ds-flash-chat-2-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net

deploy/mainnet/docker-compose.supplier-ds-flash-chat-3.yml

@@ -0,0 +1,74 @@
+# deploy/mainnet/docker-compose.supplier-ds-flash-chat-3.yml — Supplier — MAINNET
+#   (OpenRouter / deepseek-v4-flash — MULTI-TURN CHAT capability `llm.chat.v1`, REPLICA 3)
+#
+# Chat-session sibling of the deepseek-flash one-off suppliers. Same OpenRouter
+# backend (deepseek/deepseek-v4-flash) but CAPABILITY_KIND=chat-session so it
+# mounts /v1/chat/{start,message,end}. Ticket settle mode (matches the mainnet
+# gateway): the buyer's Open escrow post is the only chain op; the supplier
+# never Claims/Submits; the gateway sweeper reclaims after deliver_by.
+#
+# Pre-flight:
+#   1. DNS A-record: mp-suppliers-ds-flash-chat-3.vector.apexfusion.org -> host IP
+#   2. New supplier wallet (gen-keypair), funded (advert post + fee float).
+#   3. Post a fresh llm.chat.v1 advert for this wallet:
+#        --capability-id llm.chat.v1 --model deepseek/deepseek-v4-flash
+#        --max-processing-ms 1800000 --price-lovelace 200000
+#   4. supplier/.env.ds-flash-chat-3 written on host (chmod 600) with at least:
+#        SUPPLIER_PRIV_KEY_HEX, OPENAI_API_KEY, OGMIOS_URL, NETWORK_ID=1,
+#        VECTOR_ZERO_TIME_MS, ESCROW_REF_UTXO, ADVERT_REF_UTXO, ADVERT_REF,
+#        LIVE_CHAIN=1, OPENAI_REASONING=off, OPENAI_MAX_TOKENS=131072
+
+name: marketplace-mainnet-supplier-ds-flash-chat-3
+
+services:
+  supplier:
+    build:
+      context: ../..
+      dockerfile: supplier/Dockerfile
+    container_name: marketplace-mainnet-supplier-ds-flash-chat-3
+    restart: unless-stopped
+    env_file:
+      - path: ../../supplier/.env.ds-flash-chat-3
+        required: false
+    environment:
+      # Multi-turn chat session capability (mounts /v1/chat/{start,message,end}).
+      CAPABILITY_KIND: chat-session
+      LLM_BACKEND: openai
+      # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
+      OPENAI_BASE_URL: https://openrouter.ai/api
+      OPENAI_TIMEOUT_MS: "300000"
+      CHAT_IDLE_TIMEOUT_MS: "900000"
+      CHAT_SETTLE_MODE: ticket
+      MAX_CHAT_SESSIONS: "8"
+      PORT: "8080"
+      # Enable LiveOgmiosProvider so wallet-health/consolidate can broadcast.
+      LIVE_CHAIN: "1"
+      # NETWORK_ID and OGMIOS_URL come from supplier/.env.ds-flash-chat-3.
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      - "traefik.http.routers.mp-suppliers-ds-flash-chat-3-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-suppliers-ds-flash-chat-3-mainnet.rule=Host(`mp-suppliers-ds-flash-chat-3.vector.apexfusion.org`)"
+      - "traefik.http.services.mp-suppliers-ds-flash-chat-3-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net

deploy/mainnet/docker-compose.supplier-kimi-2.yml

@@ -0,0 +1,67 @@
+# deploy/mainnet/docker-compose.supplier-kimi-2.yml — Supplier — MAINNET (OpenRouter / Kimi K2.6 replica #2)
+#
+# Parallel-capacity replica of supplier-kimi (OpenRouter, moonshotai/kimi-k2.6).
+# Identical to docker-compose.supplier-kimi.yml except for the instance name,
+# container name, env file, Traefik host/router, and OPENAI_TIMEOUT_MS (raised
+# to 3600000 to match this advert's max_processing_ms=3600000, max_output_tokens=262144).
+# Shares the same OpenRouter API key as the other kimi suppliers (accepted
+# concurrency ceiling; supplier has no 429/backoff).
+#
+# Pre-flight:
+#   1. DNS (proxied): mp-suppliers-kimi-2.vector.apexfusion.org → host
+#   2. supplier/.env.kimi-2 on host (chmod 600): SUPPLIER_PRIV_KEY_HEX, OPENAI_API_KEY,
+#        OGMIOS_URL, NETWORK_ID=1, VECTOR_ZERO_TIME_MS, ESCROW_REF_UTXO, ADVERT_REF_UTXO,
+#        ADVERT_REF, LIVE_CHAIN=1
+#   3. Networks marketplace-mainnet-net + traefik-net already exist.
+
+name: marketplace-mainnet-supplier-kimi-2
+
+services:
+  supplier:
+    build:
+      context: ../..
+      dockerfile: supplier/Dockerfile
+    container_name: marketplace-mainnet-supplier-kimi-2
+    restart: unless-stopped
+    env_file:
+      - path: ../../supplier/.env.kimi-2
+        required: false
+    environment:
+      LLM_BACKEND: openai
+      # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
+      OPENAI_BASE_URL: https://openrouter.ai/api
+      # Raised to match the advert's max_processing_ms=3600000 (60 min) so the
+      # upstream call isn't aborted before the advertised processing deadline.
+      OPENAI_TIMEOUT_MS: "3600000"
+      PORT: "8080"
+      LIVE_CHAIN: "1"
+      # NETWORK_ID and OGMIOS_URL intentionally not pinned here — they MUST
+      # come from supplier/.env.kimi-2 on the mainnet host (footgun avoidance).
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      - "traefik.http.routers.mp-suppliers-kimi-2-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-suppliers-kimi-2-mainnet.rule=Host(`mp-suppliers-kimi-2.vector.apexfusion.org`)"
+      - "traefik.http.services.mp-suppliers-kimi-2-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net

deploy/mainnet/docker-compose.supplier-kimi-3.yml

@@ -0,0 +1,67 @@
+# deploy/mainnet/docker-compose.supplier-kimi-3.yml — Supplier — MAINNET (OpenRouter / Kimi K2.6 replica #3)
+#
+# Parallel-capacity replica of supplier-kimi (OpenRouter, moonshotai/kimi-k2.6).
+# Identical to docker-compose.supplier-kimi.yml except for the instance name,
+# container name, env file, Traefik host/router, and OPENAI_TIMEOUT_MS (raised
+# to 3600000 to match this advert's max_processing_ms=3600000, max_output_tokens=262144).
+# Shares the same OpenRouter API key as the other kimi suppliers (accepted
+# concurrency ceiling; supplier has no 429/backoff).
+#
+# Pre-flight:
+#   1. DNS (proxied): mp-suppliers-kimi-3.vector.apexfusion.org → host
+#   2. supplier/.env.kimi-3 on host (chmod 600): SUPPLIER_PRIV_KEY_HEX, OPENAI_API_KEY,
+#        OGMIOS_URL, NETWORK_ID=1, VECTOR_ZERO_TIME_MS, ESCROW_REF_UTXO, ADVERT_REF_UTXO,
+#        ADVERT_REF, LIVE_CHAIN=1
+#   3. Networks marketplace-mainnet-net + traefik-net already exist.
+
+name: marketplace-mainnet-supplier-kimi-3
+
+services:
+  supplier:
+    build:
+      context: ../..
+      dockerfile: supplier/Dockerfile
+    container_name: marketplace-mainnet-supplier-kimi-3
+    restart: unless-stopped
+    env_file:
+      - path: ../../supplier/.env.kimi-3
+        required: false
+    environment:
+      LLM_BACKEND: openai
+      # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
+      OPENAI_BASE_URL: https://openrouter.ai/api
+      # Raised to match the advert's max_processing_ms=3600000 (60 min) so the
+      # upstream call isn't aborted before the advertised processing deadline.
+      OPENAI_TIMEOUT_MS: "3600000"
+      PORT: "8080"
+      LIVE_CHAIN: "1"
+      # NETWORK_ID and OGMIOS_URL intentionally not pinned here — they MUST
+      # come from supplier/.env.kimi-3 on the mainnet host (footgun avoidance).
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      - "traefik.http.routers.mp-suppliers-kimi-3-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-suppliers-kimi-3-mainnet.rule=Host(`mp-suppliers-kimi-3.vector.apexfusion.org`)"
+      - "traefik.http.services.mp-suppliers-kimi-3-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net

deploy/mainnet/docker-compose.supplier-kimi-4.yml

@@ -0,0 +1,67 @@
+# deploy/mainnet/docker-compose.supplier-kimi-4.yml — Supplier — MAINNET (OpenRouter / Kimi K2.6 replica #4)
+#
+# Parallel-capacity replica of supplier-kimi (OpenRouter, moonshotai/kimi-k2.6).
+# Identical to docker-compose.supplier-kimi.yml except for the instance name,
+# container name, env file, Traefik host/router, and OPENAI_TIMEOUT_MS (raised
+# to 3600000 to match this advert's max_processing_ms=3600000, max_output_tokens=262144).
+# Shares the same OpenRouter API key as the other kimi suppliers (accepted
+# concurrency ceiling; supplier has no 429/backoff).
+#
+# Pre-flight:
+#   1. DNS (proxied): mp-suppliers-kimi-4.vector.apexfusion.org → host
+#   2. supplier/.env.kimi-4 on host (chmod 600): SUPPLIER_PRIV_KEY_HEX, OPENAI_API_KEY,
+#        OGMIOS_URL, NETWORK_ID=1, VECTOR_ZERO_TIME_MS, ESCROW_REF_UTXO, ADVERT_REF_UTXO,
+#        ADVERT_REF, LIVE_CHAIN=1
+#   3. Networks marketplace-mainnet-net + traefik-net already exist.
+
+name: marketplace-mainnet-supplier-kimi-4
+
+services:
+  supplier:
+    build:
+      context: ../..
+      dockerfile: supplier/Dockerfile
+    container_name: marketplace-mainnet-supplier-kimi-4
+    restart: unless-stopped
+    env_file:
+      - path: ../../supplier/.env.kimi-4
+        required: false
+    environment:
+      LLM_BACKEND: openai
+      # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
+      OPENAI_BASE_URL: https://openrouter.ai/api
+      # Raised to match the advert's max_processing_ms=3600000 (60 min) so the
+      # upstream call isn't aborted before the advertised processing deadline.
+      OPENAI_TIMEOUT_MS: "3600000"
+      PORT: "8080"
+      LIVE_CHAIN: "1"
+      # NETWORK_ID and OGMIOS_URL intentionally not pinned here — they MUST
+      # come from supplier/.env.kimi-4 on the mainnet host (footgun avoidance).
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      - "traefik.http.routers.mp-suppliers-kimi-4-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-suppliers-kimi-4-mainnet.rule=Host(`mp-suppliers-kimi-4.vector.apexfusion.org`)"
+      - "traefik.http.services.mp-suppliers-kimi-4-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net

deploy/mainnet/docker-compose.supplier-kimi-chat-2.yml

@@ -0,0 +1,78 @@
+# deploy/mainnet/docker-compose.supplier-kimi-chat-2.yml — Supplier — MAINNET
+#   (OpenRouter / Kimi K2.6 — MULTI-TURN CHAT capability `llm.chat.v1`, REPLICA 2)
+#
+# Second llm.chat.v1 replica: a chat session holds a supplier's single slot for
+# the whole conversation, so concurrent chat users = number of chat suppliers.
+# Deployed for the shared-demo-key endpoint (session-backed /chat/completions).
+# Identical to docker-compose.supplier-kimi-chat.yml except for its own wallet,
+# advert, env file and hostname.
+#
+# Pre-flight:
+#   1. DNS A-record: mp-suppliers-kimi-chat-2.vector.apexfusion.org → host IP
+#   2. New supplier wallet (gen-keypair), funded with advert bond + fee float.
+#   3. Post a fresh llm.chat.v1 advert for this wallet:
+#        --capability-id llm.chat.v1 --model moonshotai/kimi-k2.6
+#        --max-processing-ms 1800000  (same price as the primary chat advert)
+#   4. supplier/.env.kimi-chat-2 written on host (chmod 600) with at minimum:
+#        SUPPLIER_PRIV_KEY_HEX, OPENAI_API_KEY, OGMIOS_URL, NETWORK_ID=1,
+#        VECTOR_ZERO_TIME_MS, ESCROW_REF_UTXO, ADVERT_REF_UTXO, ADVERT_REF,
+#        LIVE_CHAIN=1
+
+name: marketplace-mainnet-supplier-kimi-chat-2
+
+services:
+  supplier:
+    build:
+      context: ../..
+      dockerfile: supplier/Dockerfile
+    container_name: marketplace-mainnet-supplier-kimi-chat-2
+    restart: unless-stopped
+    env_file:
+      - path: ../../supplier/.env.kimi-chat-2
+        required: false
+    environment:
+      # Multi-turn chat session capability (mounts /v1/chat/{start,message,end}).
+      CAPABILITY_KIND: chat-session
+      LLM_BACKEND: openai
+      # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
+      OPENAI_BASE_URL: https://openrouter.ai/api
+      # Kimi K2.6 generations can be slow; mirror the one-off Kimi compose.
+      OPENAI_TIMEOUT_MS: "300000"
+      # 2.5 min idle end: single-slot suppliers must free up quickly for the
+      # shared demo endpoint (the gateway transparently reopens on next turn).
+      CHAT_IDLE_TIMEOUT_MS: "900000"
+      CHAT_SETTLE_MODE: ticket
+      MAX_CHAT_SESSIONS: "8"
+      PORT: "8080"
+      # Enable LiveOgmiosProvider so Claim/Submit actually broadcast.
+      LIVE_CHAIN: "1"
+      # NETWORK_ID and OGMIOS_URL intentionally not pinned here — they MUST
+      # come from the operator-provided supplier/.env.kimi-chat-2 on a mainnet host.
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      - "traefik.http.routers.mp-suppliers-kimi-chat-2-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-suppliers-kimi-chat-2-mainnet.rule=Host(`mp-suppliers-kimi-chat-2.vector.apexfusion.org`)"
+      - "traefik.http.services.mp-suppliers-kimi-chat-2-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net

deploy/mainnet/docker-compose.supplier-kimi-chat-3.yml

@@ -0,0 +1,78 @@
+# deploy/mainnet/docker-compose.supplier-kimi-chat-3.yml — Supplier — MAINNET
+#   (OpenRouter / Kimi K2.6 — MULTI-TURN CHAT capability `llm.chat.v1`, REPLICA 3)
+#
+# Third llm.chat.v1 replica: a chat session holds a supplier's single slot for
+# the whole conversation, so concurrent chat users = number of chat suppliers.
+# Deployed for the shared-demo-key endpoint (session-backed /chat/completions).
+# Identical to docker-compose.supplier-kimi-chat.yml except for its own wallet,
+# advert, env file and hostname.
+#
+# Pre-flight:
+#   1. DNS A-record: mp-suppliers-kimi-chat-3.vector.apexfusion.org → host IP
+#   2. New supplier wallet (gen-keypair), funded with advert bond + fee float.
+#   3. Post a fresh llm.chat.v1 advert for this wallet:
+#        --capability-id llm.chat.v1 --model moonshotai/kimi-k2.6
+#        --max-processing-ms 1800000  (same price as the primary chat advert)
+#   4. supplier/.env.kimi-chat-3 written on host (chmod 600) with at minimum:
+#        SUPPLIER_PRIV_KEY_HEX, OPENAI_API_KEY, OGMIOS_URL, NETWORK_ID=1,
+#        VECTOR_ZERO_TIME_MS, ESCROW_REF_UTXO, ADVERT_REF_UTXO, ADVERT_REF,
+#        LIVE_CHAIN=1
+
+name: marketplace-mainnet-supplier-kimi-chat-3
+
+services:
+  supplier:
+    build:
+      context: ../..
+      dockerfile: supplier/Dockerfile
+    container_name: marketplace-mainnet-supplier-kimi-chat-3
+    restart: unless-stopped
+    env_file:
+      - path: ../../supplier/.env.kimi-chat-3
+        required: false
+    environment:
+      # Multi-turn chat session capability (mounts /v1/chat/{start,message,end}).
+      CAPABILITY_KIND: chat-session
+      LLM_BACKEND: openai
+      # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
+      OPENAI_BASE_URL: https://openrouter.ai/api
+      # Kimi K2.6 generations can be slow; mirror the one-off Kimi compose.
+      OPENAI_TIMEOUT_MS: "300000"
+      # 2.5 min idle end: single-slot suppliers must free up quickly for the
+      # shared demo endpoint (the gateway transparently reopens on next turn).
+      CHAT_IDLE_TIMEOUT_MS: "900000"
+      CHAT_SETTLE_MODE: ticket
+      MAX_CHAT_SESSIONS: "8"
+      PORT: "8080"
+      # Enable LiveOgmiosProvider so Claim/Submit actually broadcast.
+      LIVE_CHAIN: "1"
+      # NETWORK_ID and OGMIOS_URL intentionally not pinned here — they MUST
+      # come from the operator-provided supplier/.env.kimi-chat-3 on a mainnet host.
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/healthz >/dev/null || exit 1"]
+      interval: 20s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    networks:
+      - marketplace-mainnet-net
+      - traefik-net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-net"
+      - "traefik.http.routers.mp-suppliers-kimi-chat-3-mainnet.entrypoints=web"
+      - "traefik.http.routers.mp-suppliers-kimi-chat-3-mainnet.rule=Host(`mp-suppliers-kimi-chat-3.vector.apexfusion.org`)"
+      - "traefik.http.services.mp-suppliers-kimi-chat-3-mainnet.loadbalancer.server.port=8080"
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+networks:
+  marketplace-mainnet-net:
+    external: true
+    name: marketplace-mainnet-net
+  traefik-net:
+    external: true
+    name: traefik-net

deploy/mainnet/docker-compose.supplier-kimi-chat.yml

@@ -49,8 +49,12 @@ services:
       OPENAI_BASE_URL: https://openrouter.ai/api
       # Kimi K2.6 generations can be slow; mirror the one-off Kimi compose.
       OPENAI_TIMEOUT_MS: "300000"
-      # Auto-end an idle session after 5 min (supplier Submits the transcript).
-      CHAT_IDLE_TIMEOUT_MS: "300000"
+      # 2.5 min idle end (supplier Submits the transcript): single-slot
+      # suppliers must free up quickly for the shared demo endpoint (the
+      # gateway transparently reopens a session on the next turn).
+      CHAT_IDLE_TIMEOUT_MS: "900000"
+      CHAT_SETTLE_MODE: ticket
+      MAX_CHAT_SESSIONS: "8"
       PORT: "8080"
       # Enable LiveOgmiosProvider so Claim/Submit actually broadcast.
       LIVE_CHAIN: "1"

deploy/mainnet/docker-compose.supplier-kimi.yml

@@ -48,8 +48,10 @@ services:
       LLM_BACKEND: openai
       # No /v1 suffix — supplier/src/openai.ts appends /v1/chat/completions.
       OPENAI_BASE_URL: https://openrouter.ai/api
-      # Kimi K2.6 generations can be slow; mirror the DeepSeek/GPT composes.
-      OPENAI_TIMEOUT_MS: "300000"
+      # Raised to match the advert's max_processing_ms=3600000 (60 min) so the
+      # upstream call isn't aborted before the advertised processing deadline
+      # (matches the kimi-2/3/4 replicas).
+      OPENAI_TIMEOUT_MS: "3600000"
       PORT: "8080"
       # Enable LiveOgmiosProvider so submitTx/awaitTx actually broadcast.
       # Without this the supplier silently falls back to ReadOnlyOgmiosProvider

deploy/mainnet/docker-compose.wallet-monitor.yml

@@ -0,0 +1,40 @@
+# deploy/mainnet/docker-compose.wallet-monitor.yml — Wallet-balance Slack alerter — MAINNET
+#
+# A ONE-SHOT, not a long-running server: it checks every wallet listed in
+# wallet-monitor/wallets.json, posts a Slack alert for any below threshold,
+# then exits. There is no port, healthcheck, or restart policy.
+#
+# Invoked hourly by cron (see /etc/cron.d/wallet-monitor):
+#   cd /root/agents-marketplace && \
+#   docker compose -f deploy/mainnet/docker-compose.wallet-monitor.yml run --rm wallet-monitor
+#
+# One-time setup on the box:
+#   1) populate wallet-monitor/wallets.json (the 7 addresses — see the package README)
+#   2) create wallet-monitor/.env with SLACK_WEBHOOK_URL=...
+#   3) docker compose -f deploy/mainnet/docker-compose.wallet-monitor.yml build
+#   4) smoke test: docker compose -f ... run --rm -e TEST=1 wallet-monitor
+
+name: marketplace-mainnet-wallet-monitor
+
+services:
+  wallet-monitor:
+    build:
+      context: ../..
+      dockerfile: wallet-monitor/Dockerfile
+    env_file:
+      - path: ../../wallet-monitor/.env
+        required: false
+    environment:
+      # Mainnet-only service; pin the public Ogmios endpoint explicitly.
+      # (config.ts also defaults to this, but this compose is mainnet-specific.)
+      OGMIOS_URL: https://ogmios.vector.mainnet.apexfusion.org
+    volumes:
+      # The wallet list is read-only. The dedup state dir is writable and
+      # persists across runs (data/ is gitignored).
+      - ../../wallet-monitor/wallets.json:/repo/wallet-monitor/wallets.json:ro
+      - ../../wallet-monitor/data:/repo/wallet-monitor/data
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"

docs/ARCHITECTURE.md

@@ -8,13 +8,13 @@
 
 ## 1. Goal and scope
 
-**What this is.** A two-sided marketplace where buyers (agents or humans) submit prompts to suppliers running inference on their own hardware, pay with AP3X via on-chain bonded escrow on Vector L2, and receive signed-receipt responses. The primary validation goal is **technical feasibility + lifecycle** ("can it be done end-to-end"), not demand modelling or economic stress testing.
+**What this is.** A two-sided marketplace where buyers (agents or humans) submit prompts to suppliers running inference on their own hardware, with each job settled in AP3X through on-chain bonded escrow on Vector L2, and receive signed-receipt responses. The primary validation goal is **technical feasibility + lifecycle** ("can it be done end-to-end"), not demand modelling or economic stress testing.
 
 **What v1 is NOT.**
 - Not agentic on the supplier side. Suppliers answer single prompts. Buyer agents drive multiple prompts.
 - Not LLM-only in design. Capability model is open from day 1 (whisper / kokoro / image generation are planned siblings), but the first supplier is an LLM.
 - Not multi-slot. Single-slot per supplier process. Multi-capability operators run multiple processes.
-- Not multi-chain. Vector testnet first, mainnet later. Masumi / Sokosumi / USDM is target #2 (adapter, not fork).
+- Not multi-chain. Vector only (testnet and mainnet).
 - Not disputed. M1 ships happy-path escrow only. Module-1 disputes wire in M2.
 - Not streaming. `stream: true` is rejected by suppliers.
 - Not tool-calling. `tools` / `tool_choice` / `functions` are rejected by suppliers.
@@ -24,7 +24,7 @@
 
 | # | Decision |
 |---|---|
-| 1 | Payment token: **AP3X** (Vector testnet, later mainnet). Masumi = USDM, target #2. |
+| 1 | Settlement asset: **AP3X**, bonded in escrow; jobs settle in AP3X on accepted work. |
 | 2 | v1 scope: **Option C** — happy-path escrow only, no disputes. Module-1 wiring is milestone 2. |
 | 3 | Module-1 contract source: TBD — to be located or restored before M2. Not blocking M0–M1. |
 | 4 | Evidence: **signed receipt** `{prompt_hash, response_hash, model, tokens, wallclock}` + Ed25519 supplier signature. Hash on-chain, plaintext off-chain. |
@@ -283,7 +283,6 @@ Malformed datum · escrow to wrong script · supplier claims escrow addressed to
 | **M1** | Happy-path end-to-end, Hetzner CPU supplier | 2–3 wks | `qwen2.5:0.5b` on Hetzner, buyer posts → supplier claims → submits → buyer accepts; full Vector testnet lifecycle; indexer serves discovery |
 | **M2** | Module-1 dispute wiring | 2–3 wks post-M1 | Contract source located; supplier=claimer / buyer=auditor mapping; Dispute state; evidence URI; mainnet-dry-run lifecycle |
 | **M3** | Capability expansion + local lab | 2–4 wks (may overlap M2) | `speech.transcribe.v1` via Whisper live; local-lab GPU supplier with larger model; heterogeneous discovery validated |
-| **M4** | Masumi / Sokosumi adapter | later | MIP-003 HTTP shim; MIP-002 NFT registration; USDM payment path; Sokosumi listing |
 
 ## 9. Open follow-ups (not blocking M0 / M1)
 
@@ -310,5 +309,3 @@ Malformed datum · escrow to wrong script · supplier claims escrow addressed to
 - Apex-dashboard CBOR decoders: `apex-dashboard/server/cbor-decoder.ts`
 - Apex-dashboard test discipline: `apex-dashboard/tests/`
 - Prior Python reference (AP3X buyer/supplier): `./docs/buyer/`, `./docs/supplier/`
-- Masumi docs: https://docs.masumi.network/
-- MIP-003 spec: https://docs.masumi.network/mips/_mip-003

docs/EXECUTIVE_SUMMARY.md

@@ -1,412 +0,0 @@
----
-marp: true
-paginate: true
-size: 16:9
----
-
-<!--
-  EXECUTIVE_SUMMARY.md — slide-style overview of the Local Agents Marketplace.
-  Build PDF + PPTX with: bash docs/build-deck.sh
-  Edit this file; mermaid blocks are pre-rendered to docs/img/diagram-*.png.
--->
-
-<style>
-  /* ── Local Agents Marketplace — unified dark theme ────────────────────
-   * Every slide uses the same navy→indigo gradient as the title slide so
-   * the deck reads as one continuous document. Title and closing slides
-   * keep the centered hero treatment; content slides stay top-aligned but
-   * share the same palette and accent rules. */
-  :root {
-    --ink: #f1f5f9;          /* primary text on dark gradient */
-    --muted: #94a3b8;
-    --accent: #818cf8;       /* indigo-400, readable on the dark gradient */
-    --accent-deep: #4f46e5;  /* used for solid accents (h2 bar, table head) */
-    --accent-soft: rgba(129,140,248,0.12);
-    --gradient: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #312e81 100%);
-    --row-even: rgba(255,255,255,0.04);
-    --row-odd:  rgba(255,255,255,0.02);
-    --border:   rgba(255,255,255,0.10);
-  }
-  section {
-    background: var(--gradient);
-    color: var(--ink);
-    font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
-    font-size: 22px;
-    padding: 40px 60px;
-    display: flex;
-    flex-direction: column;
-    justify-content: flex-start;
-  }
-  section::after {
-    content: attr(data-marpit-pagination) ' / ' attr(data-marpit-pagination-total);
-    color: var(--muted);
-    font-size: 13px;
-  }
-  h1 {
-    font-size: 48px;
-    font-weight: 700;
-    color: #ffffff;
-    border-bottom: 4px solid var(--accent);
-    padding-bottom: 10px;
-    margin: 0 0 18px 0;
-  }
-  h2 {
-    font-size: 34px;
-    font-weight: 700;
-    color: #ffffff;
-    margin: 0 0 14px 0;
-  }
-  h2::before {
-    content: '';
-    display: inline-block;
-    width: 6px;
-    height: 28px;
-    background: var(--accent);
-    margin-right: 14px;
-    vertical-align: middle;
-    border-radius: 2px;
-  }
-  h3 { color: #c7d2fe; font-weight: 600; font-size: 24px; margin: 8px 0; }
-  p, li { margin: 6px 0; line-height: 1.45; }
-  ul, ol { margin: 8px 0 12px 0; padding-left: 28px; }
-  strong { color: #ffffff; }
-  a { color: #a5b4fc; }
-  blockquote {
-    border-left: 4px solid var(--accent);
-    background: rgba(255,255,255,0.06);
-    padding: 10px 18px;
-    color: #e0e7ff;
-    border-radius: 0 8px 8px 0;
-    margin: 10px 0;
-  }
-  code {
-    background: rgba(255,255,255,0.10);
-    color: #e0e7ff;
-    padding: 2px 6px;
-    border-radius: 4px;
-    font-size: 0.9em;
-  }
-  /* Constrain mermaid images so they always fit on a 720px-tall slide
-   * (16:9 @ 1280×720 default). Soft white card behind the diagram so the
-   * mermaid SVG (which renders on a transparent canvas with dark ink)
-   * stays readable on the navy gradient. */
-  img {
-    display: block;
-    margin: 8px auto;
-    max-width: 92%;
-    max-height: 420px;
-    object-fit: contain;
-    background: #ffffff;
-    border-radius: 10px;
-    padding: 10px;
-    box-shadow: 0 4px 16px rgba(0,0,0,0.25);
-  }
-  /* Tile grid for the local-agent versatility slide. */
-  .backends {
-    display: grid;
-    grid-template-columns: repeat(3, 1fr);
-    gap: 14px;
-    margin: 14px 0 12px 0;
-  }
-  .tile {
-    background: var(--accent-soft);
-    border: 2px solid var(--accent);
-    border-radius: 10px;
-    padding: 14px 16px;
-    text-align: center;
-    font-weight: 600;
-    color: #ffffff;
-  }
-  .tile small {
-    display: block;
-    margin-top: 4px;
-    font-weight: 400;
-    color: var(--muted);
-    font-size: 0.8em;
-  }
-  .tile.dots {
-    background: rgba(255,255,255,0.04);
-    border-style: dashed;
-    color: var(--muted);
-    font-size: 28px;
-  }
-  .pipeline {
-    text-align: center;
-    background: rgba(255,255,255,0.08);
-    border: 1px solid var(--border);
-    color: #f8fafc;
-    padding: 12px 18px;
-    border-radius: 10px;
-    margin: 6px auto 14px auto;
-    max-width: 760px;
-    font-weight: 600;
-  }
-  .pipeline span {
-    display: inline-block;
-    margin: 0 10px;
-  }
-  /* Tables sit on a solid white card so cell text reads cleanly against
-   * the dark gradient backdrop. Rounded outer corners + shadow match the
-   * mermaid card styling. `display:table` + `table-layout:fixed` are
-   * needed so the table actually consumes the full slide width — Marp's
-   * default theme leaves tables at content-natural width, which left
-   * blank gutters on either side. */
-  table {
-    display: table !important;
-    width: 100% !important;
-    table-layout: fixed;
-    border-collapse: collapse;
-    margin: 12px 0;
-    font-size: 0.82em;
-    color: #0f172a;
-    background: #ffffff;
-    border-radius: 10px;
-    overflow: hidden;
-    box-shadow: 0 4px 16px rgba(0,0,0,0.25);
-  }
-  td, th { word-wrap: break-word; overflow-wrap: anywhere; }
-  th {
-    background: var(--accent-deep);
-    color: #ffffff;
-    text-align: left;
-    padding: 9px 12px;
-    font-weight: 700;
-  }
-  td {
-    padding: 7px 12px;
-    border-bottom: 1px solid #e2e8f0;
-    color: #0f172a;
-  }
-  tr:nth-child(even) td { background: #ffffff; }
-  tr:nth-child(odd)  td { background: #f8fafc; }
-  /* code spans inside table cells need a light pill, not the dark one
-   * defined globally — otherwise they'd disappear into the white row. */
-  td code {
-    background: #eef2ff;
-    color: #1e293b;
-  }
-  /* Bold/strong inside cells must stay dark — the global rule paints
-   * <strong> white for the dark-gradient body text, which would render
-   * invisible against the white table card. */
-  td strong, th strong {
-    color: #0f172a;
-  }
-  th strong {
-    color: #ffffff;
-  }
-  /* Title slide — centered hero treatment on the same gradient. */
-  section.title {
-    text-align: center;
-    padding: 100px 80px;
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-  }
-  section.title h1 {
-    display: inline-block;
-    font-size: 64px;
-    margin: 0 auto 20px auto;
-  }
-  section.title blockquote {
-    margin: 28px auto;
-    max-width: 900px;
-  }
-  /* Closing slide — same centered treatment. */
-  section.closing {
-    text-align: center;
-    padding: 100px 80px;
-    justify-content: center;
-  }
-  section.closing h2::before { display: none; }
-  section.closing blockquote { font-size: 26px; max-width: 900px; }
-</style>
-
-<!-- _class: title -->
-
-# Local Agents Marketplace
-
-### A trust-minimised, on-chain marketplace for LLM inference
-
-Buy and sell prompt → response with **bonded escrow** on **Vector** (UTxO).
-No platform fee. No central rate-limiter. Verifiable receipts on chain.
-
-> *Status: M1 lifecycle proven end-to-end on Vector testnet — 2026-05-05.*
-
----
-
-## The problem
-
-* AI inference is **centralised** — a handful of providers, opaque pricing, account-level rate limits.
-* Local-AI hardware is **idle most of the time** — GPUs and CPUs sit unused between user prompts.
-* Buyers and sellers can't transact directly without a **trusted intermediary** taking a cut.
-* "Verifiable" claims about which model ran are usually nothing more than the provider's word.
-
-We need a **two-sided marketplace** where:
-1. Sellers monetise spare compute,
-2. Buyers get a **cryptographic receipt** of what was actually computed,
-3. **Neither side has to trust the other** — bonds + on-chain settlement enforce honesty.
-
----
-
-## How it works — three actors, one chain
-
-```mermaid
-flowchart LR
-    subgraph CHAIN[Vector — UTxO]
-        ADV[Advert UTxO<br/>capability, price, bonds]
-        ESC[Escrow UTxO<br/>locked funds + state]
-    end
-
-    SUP[🧠 Supplier<br/>local LLM node]
-    BUY[💼 Buyer<br/>app or agent]
-    IDX[🔭 Indexer<br/>read-only bulletin board]
-
-    SUP -->|publish advert| ADV
-    BUY -->|discover| IDX
-    IDX -.->|index events| CHAIN
-    BUY -->|post escrow| ESC
-    BUY -->|prompt + escrow_ref| SUP
-    SUP -->|signed receipt| BUY
-    SUP -->|claim & submit| ESC
-    BUY -->|accept & pay| ESC
-```
-
-* **Supplier** runs the inference and publishes a price.
-* **Buyer** posts the work as a bonded escrow, sends the prompt, accepts the receipt.
-* **Indexer** is a public mirror of chain state — anyone can run one. No platform middleman.
-
----
-
-## The bonded-escrow lifecycle
-
-```mermaid
-sequenceDiagram
-    autonumber
-    participant B as Buyer
-    participant Chain as Vector
-    participant S as Supplier
-    participant LLM as Local LLM<br/>(OpenAI-compatible)
-
-    S->>Chain: PostAdvert (locks supplier_bond)
-    B->>Chain: PostEscrow → Open<br/>(locks payment + bonds)
-    B->>S: POST /v1/chat/completions
-    S->>Chain: ClaimEscrow → Claimed
-    S->>LLM: run inference
-    LLM-->>S: assistant message
-    S->>Chain: SubmitEscrow → Submitted
-    S-->>B: 200 OK + signed receipt
-    B->>Chain: AcceptEscrow — supplier paid
-```
-
-Every transition is on-chain, validated by an Aiken Plutus V3 script. The receipt is signed by the supplier's advert key; prompt and response hashes are bound on chain.
-
----
-
-## What if someone misbehaves?
-
-```mermaid
-flowchart LR
-    OPEN[Open]:::norm --> CLAIMED[Claimed]:::norm --> SUBMITTED[Submitted]:::norm --> ACCEPTED[Accepted ✓]:::good
-    OPEN -->|deliver_by passed| RECLAIM[Reclaimed<br/>buyer recovers funds]:::warn
-    CLAIMED -->|deliver_by passed| RECLAIM
-    SUBMITTED -->|accept_window passed| RELEASE[Released<br/>supplier collects]:::warn
-
-    classDef norm fill:#e0e7ff,stroke:#4f46e5
-    classDef good fill:#dcfce7,stroke:#16a34a
-    classDef warn fill:#fef3c7,stroke:#d97706
-```
-
-| Failure mode | Recovery | Loss bearer |
-|---|---|---|
-| Supplier never claims/submits | Buyer **Reclaim** after `deliver_by` | Supplier — forfeits supplier_bond |
-| Buyer disappears after Submit | Supplier **Release** after `submitted_at + 10 min` | Buyer — forfeits buyer_bond |
-
-Bonds make honesty cheaper than running away. Both sides have skin in the game; no third-party arbiter is needed for the M1 happy/timeout paths.
-
----
-
-## Local-agent versatility — any OpenAI-compatible engine
-
-<div class="pipeline">
-  <span>💼 Buyer</span> →
-  <span>🧠 Supplier (OpenAI-compatible HTTP wrapper)</span> →
-  <span>backend ↓</span>
-</div>
-
-<div class="backends">
-  <div class="tile">Ollama<br/><small>local model runner</small></div>
-  <div class="tile">vLLM<br/><small>high-throughput GPU</small></div>
-  <div class="tile">llama.cpp<br/><small>CPU · Metal · ROCm</small></div>
-  <div class="tile">OpenRouter<br/><small>cloud API mux</small></div>
-  <div class="tile">openclaw / custom<br/><small>arbitrary stack</small></div>
-  <div class="tile dots">…<br/><small>any OpenAI-shaped API</small></div>
-</div>
-
-The supplier service is a thin HTTP wrapper — it forwards `/v1/chat/completions` to whatever backend is configured. Each supplier picks its own model, hardware, and engine, then advertises a `capability_id`. Buyers shop on capability + model + price.
-
----
-
-## Capability + model = task selection
-
-| Capability ID | Example models | Use case |
-|---|---|---|
-| `llm.text.generate.v1` | Llama 3 · Qwen 2.5 · Mistral · GPT-4 | Q&A, drafts, summarisation |
-| `code.completion.v1` | Codestral · DeepSeek-Coder · StarCoder | IDE tab-complete, refactor |
-| `vision.describe.v1` | LLaVA · Qwen-VL · Pixtral | Image captioning, OCR |
-| `embedding.text.v1` | nomic-embed · BGE · ada-002 | RAG indexing |
-| `audio.transcribe.v1` | whisper-large-v3 · distil-whisper | Voice-to-text |
-| `…` | … | … |
-
-* New capabilities = **just publish a new advert**. No marketplace governance gate.
-* Today's deploy uses Ollama + Qwen 2.5; switching to vLLM with Llama 3 70B is a config change, not a code change.
-
----
-
-## OpenClaw — agentic teams on your existing OpenAI seat
-
-<div class="pipeline">
-  <span>🧠 Supplier wrapper</span> →
-  <span>🦾 OpenClaw</span> →
-  <span>🪪 OpenAI ChatGPT seat (flat-rate)</span>
-</div>
-
-* **Cost-efficient by default.** OpenClaw exposes your existing **OpenAI ChatGPT subscription** as an OpenAI-compatible API. The marketplace supplier dispatches its inference against it, so an entire **agentic team** (coders, QA automation testers, release curators…) draws from the **flat-rate seat you already pay for** — no per-token metering, no surprise invoices.
-* **Reliability layer (optional, marginal cost).** OpenClaw can fall back to the **Anthropic API** or **OpenRouter** model pool when the primary seat is rate-limited, the prompt requires a different model, or you want a **second-layer hardening** of responses (e.g. cross-provider consensus on critical outputs). You only pay metered tokens for the requests that actually fall through.
-
----
-
-## Proven on Vector testnet — 2026-05-05
-
-| Step | Tx hash |
-|---|---|
-| Buyer posts escrow | `af762561…c2f7bc5` |
-| Supplier claims | (lifecycle tx) |
-| Supplier submits receipt | (lifecycle tx) |
-| Buyer accepts | `125e3cfe…7dc100d` |
-
-Funds flowed correctly: supplier received `payment + supplier_bond` (3 ADA); buyer got `buyer_bond` back.
-
-* **Browser demo:** https://mp-buyers.vector.testnet.apexfusion.org
-* **Live event stream:** https://mp-indexer.vector.testnet.apexfusion.org
-* **Test suite:** 1098 unit tests passing, full lifecycle exercised in CI.
-
----
-
-## Why UTxO + Vector
-
-* **Bonded escrow is native** — Plutus validators enforce the state machine without a custom token or oracle.
-* **Vector settles in seconds** — the buyer→claim→submit→accept loop fits inside a single chat-completion's wall clock.
-* **AP3X token** for fees and bonds — fungible, transparent, on-chain.
-* **No custom rollup, no bridge** — runs on a production chain today.
-
----
-
-<!-- _class: closing -->
-
-## The pitch in one sentence
-
-> Local Agents Marketplace turns any OpenAI-compatible inference endpoint into a **trustlessly billable service** — buyer and supplier exchange prompt, response, and payment with on-chain proof that what was paid for is what was delivered.
-
-### Try it
-
-* **Indexer (live event stream):** https://mp-indexer.vector.testnet.apexfusion.org
-* **Buyer:** https://mp-buyers.vector.testnet.apexfusion.org
-* **Supplier:** https://mp-suppliers.vector.testnet.apexfusion.org/capability

docs/buyer/README.md

@@ -1,11 +1,11 @@
 # Vector Buyer App
 
-A self-contained app for purchasing AI compute on the Vector L2 testnet (Cardano). You submit prompts, pay with AP3X tokens via on-chain escrow, and receive LLM responses from supplier nodes.
+A self-contained app for commissioning AI compute on the Vector L2 testnet. You submit prompts, bond AP3X in on-chain escrow, and receive LLM responses from supplier nodes; the escrow settles in AP3X on accepted work.
 
 ## How It Works
 
-1. You type a **prompt** and set a **payment** amount in the web UI
-2. The app posts an **escrow transaction** on-chain, locking your payment + bond
+1. You type a **prompt** and set a **price** in the web UI
+2. The app posts an **escrow transaction** on-chain, locking price + bond
 3. The app sends the task to a **supplier node** via HTTP
 4. The supplier calls an LLM, **claims** the escrow, and **submits** the result hash on-chain
 5. You see the response in the UI and can **accept** to release payment, or **dispute**
@@ -193,8 +193,8 @@ If you accept the result, you get your 1 AP3X bond back. Total cost = payment +
 
 - **Never share your .env file** - it contains your wallet seed phrase
 - **Never share your data/ folder** - it contains task history
-- The seed phrase controls your wallet funds. Back it up securely.
-- Escrow protects you: the supplier cannot take your funds without delivering a result
+- The seed phrase controls your wallet. Back it up securely.
+- Escrow protects you: the supplier cannot take your escrowed value without delivering a result
 - You have a 10-minute dispute window after receiving a result
 
 ## Troubleshooting

docs/gateway.md

@@ -0,0 +1,155 @@
+# OpenAI-Compatible API Gateway for the Vector Marketplace
+
+## Context
+
+Today the only way to send a prompt to the marketplace is the single-operator **buyer** web app (cookie auth, one shared wallet). We want external developers to use **any OpenAI SDK** against the marketplace. Design (locked through interview + a 5-lens adversarial audit of an earlier draft):
+
+- **Public, multi-tenant, custodial gateway.** Each API key is its **own buyer wallet** (own Ed25519 key, held AES-GCM-encrypted by the gateway). The user funds their own deposit address with AP3X; each request posts an on-chain escrow **from that user's wallet**. Not the deployed operator buyer.
+- **Two surfaces, two escrow models:**
+  - **One-shot completions** — `POST /openai/v1/chat/completions` (stateless, OpenAI-standard). Routes to an `llm.text.generate.v1` supplier. **One escrow per call.** `stream:true` → buffered pseudo-stream.
+  - **Chat sessions** — a Vector REST extension. Routes to an `llm.chat.v1` supplier. **One escrow per session**: fixed price locked at open, **real token streaming** per turn (no per-turn charge), settled at session close.
+- **Routing matches capability + model, not cheapest.** Per-prompt cost = the matched supplier's advertised price.
+- **Gateway auto-maintains each user's wallet** (collateral + consolidation) so requests past #1 keep working.
+- Onboarding is **self-serve via a small web UI**; the response is a **spec-clean OpenAI body + `x_vector` receipt extension**; custody is protected with **settle-on-success + a state-aware reclaim sweeper + a withdrawal path**.
+
+The audit confirmed 39 holes in the first draft (10 distinct themes). This document incorporates every fix; the "Audit-driven corrections" section maps each theme to its resolution.
+
+## Locked decisions
+
+| Area | Decision |
+|---|---|
+| Scope | Public multi-tenant OpenAI-compatible gateway; new `gateway/` pnpm package reusing the buyer `Marketplace` SDK |
+| Identity | Each API key = its own custodial buyer wallet |
+| Custody | AES-256-GCM, `GATEWAY_MASTER_KEY` (env), per-row nonce; decrypt in-memory at request time; **rotation CLI**; **withdrawal endpoint** is the user exit |
+| One-shot | `/openai/v1/chat/completions` → `llm.text.generate.v1`, 1 escrow/call, buffered (+ pseudo-stream) |
+| Chat session | `/openai/v1/chat/sessions*` → `llm.chat.v1`, 1 escrow/**session**, real SSE per turn, settle at close |
+| Routing | match `model` + required capability; pick an available supplier (status `free`\|`unknown`); **not cheapest**; fallback to next match on busy/offline |
+| Pricing | cost = matched supplier `price_lovelace`; **required balance = price + buyer_bond + supplier_bond + 5 AP3X collateral + fee reserve** |
+| Wallet health | gateway **auto-consolidates** each wallet to `{5-AP3X collateral, working}` after settle / on a tick |
+| Settlement | resolve the **Submitted** ref via indexer, `acceptResult`, **await confirm** before returning success; sweeper is backstop |
+| Sweeper | state-aware: Open/Claimed past `deliver_by` → reclaim; Submitted → retry Accept in-window; never blind-reclaim Submitted |
+| Response | OpenAI object `{id, object, created, model, choices, usage}` + `x_vector:{receipt, receipt_signature, escrow_ref}`; full streaming chunk transform + final usage chunk |
+| Hardening | `/signup` IP rate-limit, per-key request rate-limit, `SdkRegistry` LRU cap, structured logging + audit trail |
+
+## Architecture
+
+New standalone pnpm package `gateway/` (add to `pnpm-workspace.yaml`). Boots **one** shared `ChainProvider` (Ogmios, `LIVE_CHAIN=1`) + indexer URL, and an `SdkRegistry` that lazily builds **one `Marketplace` per API key** bound to that user's `WalletKey` (LRU-capped, evicted by idle). All on-chain work for a key is serialized by a per-key promise-chain mutex.
+
+### Verified reuse points (do not re-implement)
+- `Marketplace` ctor `MarketplaceOpts{chain, indexerUrl, walletKey, networkParams, historyStore?}` — `buyer/src/sdk/Marketplace.ts:117`. Per-user field is only `walletKey`.
+- `deriveWalletKey` + ed25519 hook — `buyer/src/index.ts:24-64`.
+- SDK methods: `discoverSuppliers`, `submitPrompt` (`Marketplace.ts:242`, verifies receipt but **does not settle**), `startChat`/`endChat` (chat session; `endChat` returns `acceptedRef` and awaits Accept), `acceptResult`, `reclaim`.
+- Escrow value/bonds: buyer funds `totalLocked = price + buyer_bond + supplier_bond` at PostEscrow — `packages/shared/src/tx/escrow/postEscrow.ts:132-200`. On Accept supplier gets `payment+supplier_bond`, buyer gets `buyer_bond` back.
+- Submitted-ref resolution: the buyer `/v1/accept` queries the indexer and matches the Submitted row by `posted_at` — `buyer/src/server.ts` `/v1/accept`. Gateway must mirror this.
+- Wallet health: `planConsolidate` / `consolidateWallet` (`{collateral, working}` shape, `DEFAULT_COLLATERAL_LOVELACE = 5 AP3X`) — `packages/shared/src/tx/wallet/`. Collateral assertion: `assertCollateralCandidate` — `packages/shared/src/tx/internal/liveCbor.ts`.
+- Supplier chat-session SSE `{type:"token"|"done"|"error"}` + headers — `supplier/src/server.ts` `makeChatSessionHandlers`; buyer relay in `buyer/src/server.ts` `/v1/chat/message` (note: **verbatim** passthrough — the gateway must transform to OpenAI chunks).
+- SQLite pattern (`better-sqlite3`, WAL) — `buyer/src/db/archive.ts`. Auth helpers `timingSafeCompareStrings`, `createRateLimiter` — `buyer/src/auth.ts`.
+- Indexer `SupplierView` (`model`, `capability_id`, `price_lovelace`, `buyer_bond_lovelace`, `supplier_bond_lovelace`, `status` free/working/offline/unknown, `advert_status`) — `indexer/src/routes/suppliers.ts`.
+
+## Package layout (`gateway/`)
+```
+src/
+  index.ts          # boot: config → shared chain/indexer → GatewayStore → SdkRegistry → app → listen + sweeper + wallet-health tick
+  config.ts         # GATEWAY_MASTER_KEY(64hex), INDEXER_URL, OGMIOS_URL, LIVE_CHAIN, NETWORK_ID, GATEWAY_PORT, GATEWAY_DB_DIR, rate-limit knobs
+  wallet.ts         # deriveWalletKey + ed25519 hook + genPrivKey
+  crypto/seal.ts    # aes-256-gcm seal()/open(), per-row nonce
+  db/{schema.ts,store.ts}        # api_keys, usage, sessions
+  sdk/registry.ts   # per-key Marketplace cache (LRU) + per-key Mutex
+  routing/selectSupplier.ts      # indexer query → capability+model match → available → fallback
+  openai/{shapes.ts,errors.ts,chatCompletions.ts,sessions.ts,models.ts}
+  account/routes.ts # POST /signup, GET /account, POST /account/withdraw
+  middleware/apiKeyAuth.ts, middleware/rateLimit.ts
+  walletHealth.ts   # post-settle + ticker consolidation (reuse planConsolidate)
+  sweeper.ts        # state-aware reclaim/accept-retry
+  ui/index.html
+  cli/rotate-master-key.ts       # re-encrypt all rows old→new master key
+```
+Build wiring: add `"exports": { "./sdk": "./dist/sdk/index.js" }` to `buyer/package.json`, depend `@marketplace/buyer: workspace:*` + `@marketplace/shared: workspace:*`.
+
+## SQLite schema
+```sql
+CREATE TABLE api_keys ( id TEXT PRIMARY KEY, key_hash TEXT UNIQUE NOT NULL, key_prefix TEXT NOT NULL, label TEXT,
+  wallet_pkh TEXT NOT NULL, deposit_address TEXT NOT NULL,
+  enc_priv_nonce TEXT NOT NULL, enc_priv_ct TEXT NOT NULL, enc_priv_tag TEXT NOT NULL,
+  master_key_version INTEGER NOT NULL DEFAULT 1, created_at INTEGER NOT NULL, disabled INTEGER NOT NULL DEFAULT 0 );
+CREATE TABLE usage ( id TEXT PRIMARY KEY, key_id TEXT NOT NULL, created_at INTEGER NOT NULL, kind TEXT NOT NULL,
+  model TEXT, capability_id TEXT, supplier_pkh TEXT, escrow_ref TEXT, cost_lovelace TEXT,
+  prompt_tokens INTEGER DEFAULT 0, completion_tokens INTEGER DEFAULT 0, status TEXT NOT NULL, failure_reason TEXT );
+CREATE TABLE sessions ( id TEXT PRIMARY KEY, key_id TEXT NOT NULL, escrow_ref TEXT NOT NULL, session_nonce TEXT NOT NULL,
+  supplier_base_url TEXT NOT NULL, model TEXT NOT NULL, state TEXT NOT NULL, opened_at INTEGER NOT NULL, closed_at INTEGER );
+```
+Raw API key never persisted (only `sha256(key)`); `key_prefix` for display. `master_key_version` enables rotation.
+
+## Endpoints
+
+**One-shot (OpenAI standard):**
+- `POST /openai/v1/chat/completions` — Bearer. Parse `{model, messages, max_tokens?, stream?}`; **reject** `tools`/`tool_choice`/`functions` with 400; **ignore** `temperature/n/stop/top_p/...` (documented). Lifecycle below.
+- `GET /openai/v1/models` — distinct `model` over Active suppliers → OpenAI list shape.
+
+**Chat sessions (Vector extension — documented as non-standard):**
+- `POST /openai/v1/chat/sessions {model}` — open: route to `llm.chat.v1`, `startChat` (lock fixed price), persist session row → `{session_id, model}`.
+- `POST /openai/v1/chat/sessions/{id}/messages {messages|content, stream}` — real SSE turn; transform supplier `{type:token}` → `chat.completion.chunk`; final usage chunk + `[DONE]`. No new escrow.
+- `POST /openai/v1/chat/sessions/{id}/close` — settle: `endChat` (Submit+Accept, awaits), record usage, then run wallet-health.
+
+**Account / UI:**
+- `POST /signup {label?}` — IP rate-limited. Generate priv → derive → seal → store → `{api_key (once), deposit_address, key_prefix}`.
+- `GET /account` — Bearer. `{deposit_address, balance:{available_lovelace, locked_in_escrow_lovelace, ap3x}, collateral_ok:bool, spend:{total_cost_lovelace, request_count}, recent_usage[]}`.
+- `POST /account/withdraw {to_address, amount_lovelace?}` — Bearer. Build a wallet→address transfer (new `buildWithdrawTx` in packages/shared; repo has no send tx today) sending available funds out. **The custodial exit path.**
+- `GET /` — self-serve UI (create key, copy deposit address, live balances, usage, withdraw).
+
+## Request lifecycle — one-shot `/chat/completions`
+All on-chain steps run inside the per-key `mutex.run(...)`.
+1. **Route** (`selectSupplier`): indexer rows where `model` matches, `capability_id==="llm.text.generate.v1"`, `advert_status==="Active"`, live `status ∈ {free, unknown}`. Pick an available one (not cheapest). No match → 404 `model_not_found` (`type: invalid_request_error`).
+2. **Pre-flight**: required = `price + buyer_bond + supplier_bond + 5_000_000 (collateral) + ~2 AP3X fee`. Verify total balance **and** a pure-AP3X UTxO ≥5 AP3X exists (`assertCollateralCandidate`-style). Else 402 `insufficient_funds` + `x_vector:{required_lovelace, available_lovelace, collateral_ok, deposit_address}`.
+3. **Execute**: `submitPrompt({advertRef, messages, payment_lovelace:price, max_output_tokens})` (posts escrow → supplier → verifies receipt).
+4. **Settle**: resolve the **Submitted** escrow ref via the indexer (mirror buyer `/v1/accept`: match by buyer pkh + `posted_at`), `acceptResult(submittedRef)`, **await confirmation**. On 409/offline mid-route, retry next matching supplier (bounded). On any post-escrow failure, record + leave for the sweeper (don't block the response on reclaim).
+5. **Respond**: `{id:"chatcmpl-…", object:"chat.completion", created:<sec>, model, choices:[{index:0,message:{role:"assistant",content},finish_reason:"stop"}], usage:{prompt_tokens,completion_tokens,total_tokens}, x_vector:{receipt,receipt_signature,escrow_ref}}`. Record `usage`.
+6. **Wallet health**: after settle, consolidate the wallet back to `{collateral, working}` (inside the mutex or queued).
+7. `stream:true`: same flow; emit one (or chunked) `chat.completion.chunk` delta + final `finish_reason:"stop"` chunk **with `usage`** + `data: [DONE]`. Emit `: keepalive` SSE comments during the escrow-confirm gap.
+
+## Chat-session lifecycle
+- **open** → `startChat` (escrow at fixed price), store `{escrow_ref, session_nonce, supplier_base_url}`.
+- **messages** → POST the turn to `${supplier_base_url}/v1/chat/message` with `X-Escrow-Ref`; transform each `{type:token,value}` → `chat.completion.chunk`; `{type:done}` → final chunk + usage + `[DONE]`. (System messages: fold into the first turn's content; documented limitation since chat.v1 has no system channel.)
+- **close** → `endChat` (Submit + Accept, awaits) → settle + bond refund; record usage; wallet-health.
+- Sessions are reclaimable by the sweeper if abandoned before close.
+
+### Settle modes (`CHAT_SETTLE_MODE`, gateway + supplier, default `full`)
+- **full** — the lifecycle above: supplier Claims at start, Submits a transcript receipt at end, gateway Accepts (buyer charged).
+- **ticket** — the buyer's escrow post at open is the ONLY chain op. The supplier verifies the Open escrow as an entry ticket (`/v1/chat/start` → `{status:"ticket"}`) but never Claims/Submits; `/v1/chat/end` → `{status:"ended", settle_mode:"ticket"}` with no receipt; the sweeper Reclaims the Open escrow after `deliver_by`, returning all locked funds (net cost ≈ tx fees). Usage rows record `cost_lovelace: 0`. Sessions may outlive `deliver_by` (no hard-cap) — a live session whose ticket got reclaimed keeps running; only the idle janitor/close ends it. Close behavior is driven per-session by the supplier's `/end` response, so mixed-mode rollout windows settle correctly.
+- Ticket caveats (accepted, demo-grade): a supplier restart forgets used tickets, so an unexpired un-reclaimed escrow ref could reopen a session (bounded by `deliver_by` + the sweep); `/account.locked_in_escrow_lovelace` over-reports because the indexer never updates spent rows.
+- Suppliers additionally take `MAX_CHAT_SESSIONS` (default 1) — concurrent session slots; `/status` reports `active_sessions`/`max_sessions` and stays `free` until all slots are taken.
+
+## Sweeper & wallet-health
+- **Sweeper** (interval ~60s): per key, classify escrows. Open/Claimed past `deliver_by` → `reclaim`. Submitted **with a verified receipt** still in accept-window → retry `acceptResult`. Submitted past accept-window → leave for supplier Release (log). Never blind-`reclaim` Submitted.
+- **Wallet-health tick**: periodically + after each settle, `planConsolidate` → `consolidateWallet` so every wallet keeps a ≥5 AP3X collateral UTxO. Skip if already healthy.
+
+## Errors (OpenAI shape `{error:{message, type, code, param:null}}`)
+no supplier → 404 `invalid_request_error`/`model_not_found`; underfunded/no-collateral → 402 `invalid_request_error`/`insufficient_funds`; bad/missing key → 401 `authentication_error`/`invalid_api_key`; rate limit → 429 `rate_limit_error` + `Retry-After`; supplier timeout → 504 `server_error`; supplier busy race (after retries) → 503 `server_error`/`overloaded`; receipt verify → 502 `server_error`/`receipt_verification_failed`; tx build → 409/502 `server_error`/`escrow_failed`; unsupported `tools`/`functions` → 400 `invalid_request_error`/`unsupported_parameter`.
+
+## Audit-driven corrections (themes → resolution)
+1. **Settlement/Submitted-ref + fire-and-forget Accept** → lifecycle step 4 (indexer resolution + awaited Accept); sweeper backstop.
+2. **No withdrawal** → `POST /account/withdraw` + new `buildWithdrawTx`.
+3. **Master-key SPOF / offline-stranding** → documented backup, `rotate-master-key` CLI (`master_key_version`), withdrawal as exit; trustless recovery (pre-signed reclaim / multisig) explicitly **out of scope**, documented as residual risk.
+4. **Stateless↔stateful chat** → sessions are explicit (open/messages/close), one escrow/session; system-message folding documented.
+5. **Collateral/fragmentation** → corrected required-balance formula + pre-flight collateral check + auto wallet-health consolidation.
+6. **~0.5 req/min throughput** (awaitTx in mutex) → documented per-key SLA; "move awaitTx out of the lock" noted as fast-follow.
+7. **Sweeper can't reclaim Submitted** → state-aware sweeper.
+8. **OpenAI wire format** → full response object + chunk transform + final usage chunk + keepalive + error taxonomy + param policy.
+9. **Hardening** → `/signup` IP limit, per-key request limit, `SdkRegistry` LRU cap, `status ∈ {free,unknown}` + freshness + fallback retry.
+10. **Economics/observability** → v1 = **no on-chain margin** (operator subsidizes infra; a fee needs a separate transfer or off-chain credit — folded into the deferred "billing" phase); add structured per-request logging + audit (request_id, key_id, model, supplier_pkh, escrow_ref, status, latency) + basic metrics/alerts (indexer stale, Ogmios slow, sweeper idle).
+- **Doc fix**: clarify the **off-chain tx builder** enforces `payment==advert.price`; the validator only enforces the state machine, not pricing.
+
+## Out of scope for v1 (documented)
+Real billing/markup & fee hook; trustless/self-custody recovery; multi-funding-UTxO optimization beyond the consolidation loop; moving `awaitTx` out of the per-key lock; real chat.v1 system-role support (needs a supplier API change).
+
+## Verification (testnet, end-to-end)
+1. Indexer + Ogmios + ≥1 `llm.text.generate.v1` and ≥1 `llm.chat.v1` supplier for the same `model`, Active.
+2. Boot gateway: `LIVE_CHAIN=1`, `GATEWAY_MASTER_KEY=$(openssl rand -hex 32)`, `OGMIOS_URL`, `INDEXER_URL`, `NETWORK_ID`, `GATEWAY_DB_DIR`, `GATEWAY_PORT`.
+3. `POST /signup` → key + deposit address. Fund ≥ price + both bonds + 5 AP3X collateral + ~2 AP3X fees; confirm via `GET /account` (`collateral_ok:true`).
+4. One-shot non-stream via curl and via the OpenAI Python/JS SDK (`base_url=…/openai/v1`) → valid `chat.completion` + `x_vector`; confirm the escrow **settled (Accepted)** and a `usage` row exists.
+5. **Run a 2nd and 3rd request** → confirm wallet-health kept `collateral_ok` and they succeed (the audit's request-#2 failure must not reproduce).
+6. One-shot `stream:true` → chunks + final usage + `[DONE]`.
+7. Chat session: open → stream 2–3 turns → close; confirm **one** escrow for the whole session, settled at close.
+8. `POST /account/withdraw` → unspent AP3X returns to an external address.
+9. Underfunded / no-collateral key → 402 with guidance. Unknown model → 404. `tools:[…]` → 400.
+10. Kill gateway mid-request → restart → sweeper reclaims Open/Claimed and retries Accept on Submitted; balances recover.

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-
-# Local Agents Marketplace
-
-### A trust-minimised, on-chain marketplace for LLM inference
-
-Buy and sell prompt → response with **bonded escrow** on **Vector** (UTxO).
-No platform fee. No central rate-limiter. Verifiable receipts on chain.
-
-> *Status: M1 lifecycle proven end-to-end on Vector testnet — 2026-05-05.*
-
----
-
-## The problem
-
-* AI inference is **centralised** — a handful of providers, opaque pricing, account-level rate limits.
-* Local-AI hardware is **idle most of the time** — GPUs and CPUs sit unused between user prompts.
-* Buyers and sellers can't transact directly without a **trusted intermediary** taking a cut.
-* "Verifiable" claims about which model ran are usually nothing more than the provider's word.
-
-We need a **two-sided marketplace** where:
-1. Sellers monetise spare compute,
-2. Buyers get a **cryptographic receipt** of what was actually computed,
-3. **Neither side has to trust the other** — bonds + on-chain settlement enforce honesty.
-
----
-
-## How it works — three actors, one chain
-
-```mermaid
-flowchart LR
-    subgraph CHAIN[Vector — UTxO]
-        ADV[Advert UTxO<br/>capability, price, bonds]
-        ESC[Escrow UTxO<br/>locked funds + state]
-    end
-
-    SUP[🧠 Supplier<br/>local LLM node]
-    BUY[💼 Buyer<br/>app or agent]
-    IDX[🔭 Indexer<br/>read-only bulletin board]
-
-    SUP -->|publish advert| ADV
-    BUY -->|discover| IDX
-    IDX -.->|index events| CHAIN
-    BUY -->|post escrow| ESC
-    BUY -->|prompt + escrow_ref| SUP
-    SUP -->|signed receipt| BUY
-    SUP -->|claim & submit| ESC
-    BUY -->|accept & pay| ESC
-```
-
-* **Supplier** runs the inference and publishes a price.
-* **Buyer** posts the work as a bonded escrow, sends the prompt, accepts the receipt.
-* **Indexer** is a public mirror of chain state — anyone can run one. No platform middleman.
-
----
-
-## The bonded-escrow lifecycle
-
-```mermaid
-sequenceDiagram
-    autonumber
-    participant B as Buyer
-    participant Chain as Vector
-    participant S as Supplier
-    participant LLM as Local LLM<br/>(OpenAI-compatible)
-
-    S->>Chain: PostAdvert (locks supplier_bond)
-    B->>Chain: PostEscrow → Open<br/>(locks payment + bonds)
-    B->>S: POST /v1/chat/completions
-    S->>Chain: ClaimEscrow → Claimed
-    S->>LLM: run inference
-    LLM-->>S: assistant message
-    S->>Chain: SubmitEscrow → Submitted
-    S-->>B: 200 OK + signed receipt
-    B->>Chain: AcceptEscrow — supplier paid
-```
-
-Every transition is on-chain, validated by an Aiken Plutus V3 script. The receipt is signed by the supplier's advert key; prompt and response hashes are bound on chain.
-
----
-
-## What if someone misbehaves?
-
-```mermaid
-flowchart LR
-    OPEN[Open]:::norm --> CLAIMED[Claimed]:::norm --> SUBMITTED[Submitted]:::norm --> ACCEPTED[Accepted ✓]:::good
-    OPEN -->|deliver_by passed| RECLAIM[Reclaimed<br/>buyer recovers funds]:::warn
-    CLAIMED -->|deliver_by passed| RECLAIM
-    SUBMITTED -->|accept_window passed| RELEASE[Released<br/>supplier collects]:::warn
-
-    classDef norm fill:#e0e7ff,stroke:#4f46e5
-    classDef good fill:#dcfce7,stroke:#16a34a
-    classDef warn fill:#fef3c7,stroke:#d97706
-```
-
-| Failure mode | Recovery | Loss bearer |
-|---|---|---|
-| Supplier never claims/submits | Buyer **Reclaim** after `deliver_by` | Supplier — forfeits supplier_bond |
-| Buyer disappears after Submit | Supplier **Release** after `submitted_at + 10 min` | Buyer — forfeits buyer_bond |
-
-Bonds make honesty cheaper than running away. Both sides have skin in the game; no third-party arbiter is needed for the M1 happy/timeout paths.
-
----
-
-## Local-agent versatility — any OpenAI-compatible engine
-
-<div class="pipeline">
-  <span>💼 Buyer</span> →
-  <span>🧠 Supplier (OpenAI-compatible HTTP wrapper)</span> →
-  <span>backend ↓</span>
-</div>
-
-<div class="backends">
-  <div class="tile">Ollama<br/><small>local model runner</small></div>
-  <div class="tile">vLLM<br/><small>high-throughput GPU</small></div>
-  <div class="tile">llama.cpp<br/><small>CPU · Metal · ROCm</small></div>
-  <div class="tile">OpenRouter<br/><small>cloud API mux</small></div>
-  <div class="tile">openclaw / custom<br/><small>arbitrary stack</small></div>
-  <div class="tile dots">…<br/><small>any OpenAI-shaped API</small></div>
-</div>
-
-The supplier service is a thin HTTP wrapper — it forwards `/v1/chat/completions` to whatever backend is configured. Each supplier picks its own model, hardware, and engine, then advertises a `capability_id`. Buyers shop on capability + model + price.
-
----
-
-## Capability + model = task selection
-
-| Capability ID | Example models | Use case |
-|---|---|---|
-| `llm.text.generate.v1` | Llama 3 · Qwen 2.5 · Mistral · GPT-4 | Q&A, drafts, summarisation |
-| `code.completion.v1` | Codestral · DeepSeek-Coder · StarCoder | IDE tab-complete, refactor |
-| `vision.describe.v1` | LLaVA · Qwen-VL · Pixtral | Image captioning, OCR |
-| `embedding.text.v1` | nomic-embed · BGE · ada-002 | RAG indexing |
-| `audio.transcribe.v1` | whisper-large-v3 · distil-whisper | Voice-to-text |
-| `…` | … | … |
-
-* New capabilities = **just publish a new advert**. No marketplace governance gate.
-* Today's deploy uses Ollama + Qwen 2.5; switching to vLLM with Llama 3 70B is a config change, not a code change.
-
----
-
-## OpenClaw — agentic teams on your existing OpenAI seat
-
-<div class="pipeline">
-  <span>🧠 Supplier wrapper</span> →
-  <span>🦾 OpenClaw</span> →
-  <span>🪪 OpenAI ChatGPT seat (flat-rate)</span>
-</div>
-
-* **Cost-efficient by default.** OpenClaw exposes your existing **OpenAI ChatGPT subscription** as an OpenAI-compatible API. The marketplace supplier dispatches its inference against it, so an entire **agentic team** (coders, QA automation testers, release curators…) draws from the **flat-rate seat you already pay for** — no per-token metering, no surprise invoices.
-* **Reliability layer (optional, marginal cost).** OpenClaw can fall back to the **Anthropic API** or **OpenRouter** model pool when the primary seat is rate-limited, the prompt requires a different model, or you want a **second-layer hardening** of responses (e.g. cross-provider consensus on critical outputs). You only pay metered tokens for the requests that actually fall through.
-
----
-
-## Proven on Vector testnet — 2026-05-05
-
-| Step | Tx hash |
-|---|---|
-| Buyer posts escrow | `af762561…c2f7bc5` |
-| Supplier claims | (lifecycle tx) |
-| Supplier submits receipt | (lifecycle tx) |
-| Buyer accepts | `125e3cfe…7dc100d` |
-
-Funds flowed correctly: supplier received `payment + supplier_bond` (3 ADA); buyer got `buyer_bond` back.
-
-* **Browser demo:** https://mp-buyers.vector.testnet.apexfusion.org
-* **Live event stream:** https://mp-indexer.vector.testnet.apexfusion.org
-* **Test suite:** 1098 unit tests passing, full lifecycle exercised in CI.
-
----
-
-## Why UTxO + Vector
-
-* **Bonded escrow is native** — Plutus validators enforce the state machine without a custom token or oracle.
-* **Vector settles in seconds** — the buyer→claim→submit→accept loop fits inside a single chat-completion's wall clock.
-* **AP3X token** for fees and bonds — fungible, transparent, on-chain.
-* **No custom rollup, no bridge** — runs on a production chain today.
-
----
-
-<!-- _class: closing -->
-
-## The pitch in one sentence
-
-> Local Agents Marketplace turns any OpenAI-compatible inference endpoint into a **trustlessly billable service** — buyer and supplier exchange prompt, response, and payment with on-chain proof that what was paid for is what was delivered.
-
-### Try it
-
-* **Indexer (live event stream):** https://mp-indexer.vector.testnet.apexfusion.org
-* **Buyer:** https://mp-buyers.vector.testnet.apexfusion.org
-* **Supplier:** https://mp-suppliers.vector.testnet.apexfusion.org/capability

docs/supplier/README.md

@@ -164,8 +164,8 @@ If the buyer does NOT accept within the dispute window (10 minutes), you can col
 
 - **Never share your .env file** - it contains your wallet seed phrase
 - **Never share your data/ folder** - it contains task history
-- The seed phrase controls your wallet funds. Back it up securely.
-- The node only responds to buyers who have already locked funds on-chain, so you cannot be scammed out of compute.
+- The seed phrase controls your wallet. Back it up securely.
+- The node only responds to buyers who have already locked value on-chain, so you cannot be scammed out of compute.
 
 ## Troubleshooting
 

gateway/.env.example

@@ -0,0 +1,36 @@
+# gateway/.env.example — copy to .env and fill in.
+
+# 32-byte (64 hex char) master key used to AES-256-GCM-encrypt every user's
+# custodial wallet private key at rest. Generate with: openssl rand -hex 32
+# LOSING THIS PERMANENTLY LOCKS ALL USER FUNDS. Back it up out-of-band.
+GATEWAY_MASTER_KEY=
+
+# Internal indexer base URL (e.g. http://marketplace-indexer:8090).
+INDEXER_URL=
+
+# Ogmios HTTP endpoint. Required (the gateway posts/settles escrows on chain).
+OGMIOS_URL=
+
+# Must be "1" — the gateway signs and submits real transactions.
+LIVE_CHAIN=1
+
+# "0" testnet (addr_test…), "1" mainnet (addr…). Default "0".
+NETWORK_ID=0
+
+# HTTP port. Default 3010.
+GATEWAY_PORT=3010
+
+# Directory holding gateway.db (custodial keys + usage + sessions). BACK IT UP.
+# Default ./data/gateway
+GATEWAY_DB_DIR=./data/gateway
+
+# Optional tuning (defaults shown):
+# SIGNUP_RATE_MAX=5            # signups per IP per window
+# SIGNUP_RATE_WINDOW_MS=3600000
+# KEY_RATE_MAX=60             # requests per API key per window
+# KEY_RATE_WINDOW_MS=60000
+# SWEEPER_INTERVAL_MS=60000
+# DEMO_SESSION_IDLE_MS=180000 # close demo chat sessions idle this long (frees the supplier slot)
+# CHAT_SETTLE_MODE=full       # "full" (Claim/Submit/Accept) or "ticket" (escrow post only; sweeper reclaims) — must match suppliers
+# WALLET_HEALTH_INTERVAL_MS=600000
+# SDK_REGISTRY_MAX=500        # max cached per-key Marketplace instances

gateway/Dockerfile

@@ -0,0 +1,70 @@
+# syntax=docker/dockerfile:1.7
+#
+# gateway/Dockerfile — multi-stage image for the OpenAI-compatible gateway.
+#
+# Mirrors buyer/Dockerfile: we do NOT run `tsc` for the server because
+# @marketplace/shared and @marketplace/buyer export .ts directly via
+# package.json#exports — the tsx loader handles them at runtime. The gateway
+# reuses the buyer's Marketplace SDK + lucid (buildAcceptTx / buildWithdrawTx),
+# so it needs the same better-sqlite3 native rebuild + libsodium patch and the
+# contracts/marketplace/plutus.json blueprint.
+#
+# Build:
+#   docker build -f gateway/Dockerfile -t marketplace-gateway .
+
+ARG NODE_VERSION=20.19.0
+
+# ─── builder ──────────────────────────────────────────────────────────────
+FROM node:${NODE_VERSION}-alpine AS builder
+WORKDIR /repo
+
+RUN apk add --no-cache python3 make g++
+RUN corepack enable && corepack prepare pnpm@10.33.2 --activate
+
+COPY pnpm-workspace.yaml pnpm-lock.yaml package.json tsconfig.base.json .npmrc ./
+COPY packages/shared/package.json ./packages/shared/package.json
+COPY buyer/package.json ./buyer/package.json
+COPY gateway/package.json ./gateway/package.json
+
+# Install the gateway and its workspace deps (buyer + shared) with their deps.
+RUN pnpm install --frozen-lockfile --filter '@marketplace/gateway...'
+
+# better-sqlite3 native binding (same step as buyer/indexer images).
+RUN BSQ_DIR=$(ls -d node_modules/.pnpm/better-sqlite3@*/node_modules/better-sqlite3 2>/dev/null | head -1) \
+ && [ -n "$BSQ_DIR" ] || (echo "FATAL: better-sqlite3 not in pnpm store" && exit 1) \
+ && (cd "$BSQ_DIR" && (npx --yes prebuild-install --runtime=node || npm install --build-from-source --no-save)) \
+ && ls -la "$BSQ_DIR/build/Release/better_sqlite3.node"
+
+# libsodium wrapper patch (lucid/CML dep) — same fix as the buyer image.
+RUN set -e \
+ && SRC=$(find node_modules/.pnpm -name "libsodium-sumo.mjs" -path "*/libsodium-sumo/dist/*" 2>/dev/null | head -1) \
+ && DST=$(find node_modules/.pnpm -type d -path "*libsodium-wrappers-sumo@*/node_modules/libsodium-wrappers-sumo/dist/modules-sumo-esm" 2>/dev/null | head -1) \
+ && [ -n "$SRC" ] && [ -n "$DST" ] || (echo "FATAL: libsodium-sumo paths not resolved" && exit 1) \
+ && cp "$SRC" "$DST/"
+
+COPY packages/shared ./packages/shared
+COPY buyer ./buyer
+COPY gateway ./gateway
+# loadBlueprint reads contracts/marketplace/plutus.json at runtime (Accept/Withdraw).
+COPY contracts/marketplace/plutus.json ./contracts/marketplace/plutus.json
+
+# ─── runtime ──────────────────────────────────────────────────────────────
+FROM node:${NODE_VERSION}-alpine AS runtime
+WORKDIR /repo
+
+RUN apk add --no-cache tini
+COPY --from=builder /repo /repo
+
+# Seed the gateway DB dir owned by node (so a fresh named volume inherits it).
+RUN mkdir -p /repo/data/gateway && chown -R node:node /repo
+USER node
+
+ENV NODE_ENV=production
+ENV GATEWAY_PORT=8080
+EXPOSE 8080
+
+HEALTHCHECK --interval=20s --timeout=5s --start-period=15s --retries=3 \
+  CMD wget -qO- http://127.0.0.1:${GATEWAY_PORT}/healthz >/dev/null || exit 1
+
+ENTRYPOINT ["/sbin/tini", "--"]
+CMD ["node_modules/.bin/tsx", "gateway/src/index.ts"]

gateway/package.json

@@ -0,0 +1,29 @@
+{
+  "name": "@marketplace/gateway",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "typecheck": "tsc --noEmit",
+    "start": "tsx src/index.ts",
+    "dev": "tsx src/index.ts",
+    "rotate-master-key": "tsx src/cli/rotate-master-key.ts",
+    "create-demo-key": "tsx src/cli/create-demo-key.ts"
+  },
+  "dependencies": {
+    "@marketplace/buyer": "workspace:*",
+    "@marketplace/shared": "workspace:*",
+    "@noble/ed25519": "^2.3.0",
+    "@noble/hashes": "^1.8.0",
+    "bech32": "^2.0.0",
+    "better-sqlite3": "^11.9.1",
+    "express": "^4.21.2"
+  },
+  "devDependencies": {
+    "@types/better-sqlite3": "^7.6.12",
+    "@types/express": "^5.0.3",
+    "supertest": "^7.0.0",
+    "tsx": "^4.19.0",
+    "typescript": "^5.7.2"
+  }
+}

gateway/src/account/routes.ts

@@ -0,0 +1,163 @@
+/**
+ * gateway/src/account/routes.ts — signup, account, withdraw.
+ *
+ *   POST /signup            → mint a custodial wallet + API key (key shown once)
+ *   GET  /account           → balance, collateral readiness, spend, recent usage
+ *   POST /account/withdraw  → move unspent AP3X out to an external address (exit)
+ */
+
+import { randomBytes, randomUUID } from "crypto";
+import type { Request, Response } from "express";
+import { buildWithdrawTx } from "@marketplace/shared/tx/server";
+import type { GatewayDeps } from "../deps.js";
+import { genPrivKeyHex, deriveWalletKey } from "../wallet.js";
+import { seal } from "../crypto/seal.js";
+import { hashApiKey, requireKey } from "../middleware/apiKeyAuth.js";
+import { asyncHandler } from "../middleware/http.js";
+import { totalLovelace, hasCollateral } from "../onchain/preflight.js";
+import { badRequest, forbidden } from "../openai/errors.js";
+
+const ACTIVE_ESCROW_STATES = new Set(["Open", "Claimed", "Submitted"]);
+
+function ap3x(lovelace: bigint): string {
+  return (Number(lovelace) / 1e6).toFixed(2);
+}
+
+// ─── signup ──────────────────────────────────────────────────────────────────
+
+export function makeSignupHandler(deps: GatewayDeps) {
+  return asyncHandler(async (req: Request, res: Response) => {
+    const body = (req.body ?? {}) as Record<string, unknown>;
+    const label = typeof body.label === "string" ? body.label.slice(0, 120) : null;
+
+    const privHex = genPrivKeyHex();
+    const walletKey = deriveWalletKey(privHex, deps.config.networkId);
+    const sealed = seal(privHex, deps.config.masterKeyHex);
+
+    const rawKey = `vk_${deps.config.networkId === 1 ? "live" : "test"}_${randomBytes(24).toString("hex")}`;
+    const keyPrefix = rawKey.slice(0, 12);
+
+    deps.store.insertKey({
+      id: randomUUID(),
+      key_hash: hashApiKey(rawKey),
+      key_prefix: keyPrefix,
+      label,
+      wallet_pkh: walletKey.pubKeyHash,
+      deposit_address: walletKey.address,
+      enc_priv_nonce: sealed.nonce,
+      enc_priv_ct: sealed.ct,
+      enc_priv_tag: sealed.tag,
+      master_key_version: 1,
+      created_at: Date.now(),
+    });
+
+    res.status(201).json({
+      api_key: rawKey,
+      key_prefix: keyPrefix,
+      deposit_address: walletKey.address,
+      note: "Save api_key now — it is shown only once. Fund deposit_address with AP3X to use the gateway.",
+    });
+  });
+}
+
+// ─── account ─────────────────────────────────────────────────────────────────
+
+export function makeAccountHandler(deps: GatewayDeps) {
+  return asyncHandler(async (req: Request, res: Response) => {
+    const keyRow = requireKey(req);
+    const utxos = await deps.chain.queryUtxosByAddress(keyRow.deposit_address);
+    const available = totalLovelace(utxos);
+
+    let lockedInEscrow = 0n;
+    try {
+      const r = await deps.fetchFn(`${deps.config.indexerUrl}/escrows?buyer=${keyRow.wallet_pkh}`);
+      if (r.ok) {
+        const rows = (await r.json()) as Array<Record<string, unknown>>;
+        if (Array.isArray(rows)) {
+          for (const row of rows) {
+            if (!ACTIVE_ESCROW_STATES.has(String(row.state))) continue;
+            lockedInEscrow +=
+              BigInt(String(row.payment_lovelace ?? "0")) +
+              BigInt(String(row.buyer_bond_lovelace ?? "0")) +
+              BigInt(String(row.supplier_bond_lovelace ?? "0"));
+          }
+        }
+      }
+    } catch {
+      /* best-effort; report 0 locked on indexer hiccup */
+    }
+
+    res.status(200).json({
+      key_prefix: keyRow.key_prefix,
+      // The shared demo key's wallet is operator-funded; hiding the deposit
+      // address keeps strangers from confusing it with their own wallet.
+      deposit_address: keyRow.demo ? null : keyRow.deposit_address,
+      ...(keyRow.demo ? { demo: true } : {}),
+      balance: {
+        available_lovelace: available.toString(),
+        locked_in_escrow_lovelace: lockedInEscrow.toString(),
+        ap3x: ap3x(available),
+      },
+      collateral_ok: hasCollateral(utxos),
+      spend: {
+        total_cost_lovelace: deps.store.sumCostLovelace(keyRow.id).toString(),
+        request_count: deps.store.countUsage(keyRow.id),
+      },
+      recent_usage: deps.store.listUsage(keyRow.id, 20).map((u) => ({
+        created_at: u.created_at,
+        kind: u.kind,
+        model: u.model,
+        status: u.status,
+        cost_lovelace: u.cost_lovelace,
+        escrow_ref: u.escrow_ref,
+        failure_reason: u.failure_reason,
+      })),
+    });
+  });
+}
+
+// ─── withdraw ────────────────────────────────────────────────────────────────
+
+export function makeWithdrawHandler(deps: GatewayDeps) {
+  return asyncHandler(async (req: Request, res: Response) => {
+    const keyRow = requireKey(req);
+    if (keyRow.demo) {
+      // The demo key is shared publicly; without this, anyone holding it
+      // could drain the operator-funded wallet to their own address.
+      throw forbidden("demo_key_restricted", "withdrawals are disabled for the shared demo key");
+    }
+    const body = (req.body ?? {}) as Record<string, unknown>;
+
+    const toAddress = body.to_address;
+    if (typeof toAddress !== "string" || !/^addr(_test)?1[0-9a-z]+$/.test(toAddress)) {
+      throw badRequest("invalid_address", "`to_address` must be a bech32 Cardano address");
+    }
+
+    let amountLovelace: bigint | undefined;
+    if (body.amount_lovelace !== undefined && body.amount_lovelace !== null) {
+      try {
+        amountLovelace = BigInt(String(body.amount_lovelace));
+      } catch {
+        throw badRequest("invalid_amount", "`amount_lovelace` must be an integer (string or number)");
+      }
+      if (amountLovelace <= 0n) throw badRequest("invalid_amount", "`amount_lovelace` must be positive");
+    }
+
+    const ctx = deps.registry.getContext(keyRow);
+    await ctx.mutex.run(async () => {
+      const built = await buildWithdrawTx({
+        chain: deps.chain,
+        walletKey: ctx.walletKey,
+        toAddress,
+        amountLovelace,
+      });
+      await deps.chain.awaitTx(built.expectedTxHash, 120_000);
+      res.status(200).json({
+        status: "submitted",
+        tx_hash: built.expectedTxHash,
+        amount_lovelace: built.amountLovelace.toString(),
+        to_address: built.toAddress,
+      });
+    });
+  });
+}

gateway/src/chain.ts

@@ -0,0 +1,16 @@
+/**
+ * gateway/src/chain.ts — the single shared LiveOgmiosProvider.
+ *
+ * The gateway always submits real transactions, so it always uses a Live
+ * provider (config enforces LIVE_CHAIN=1). One provider is shared across all
+ * per-key Marketplace instances; ChainProvider reads are concurrency-safe.
+ */
+
+import { LiveOgmiosProvider } from "@marketplace/shared/chain";
+import type { GatewayConfig } from "./config.js";
+
+export function buildChainProvider(config: GatewayConfig): LiveOgmiosProvider {
+  // eslint-disable-next-line no-console
+  console.log("[gateway] chain: LiveOgmiosProvider");
+  return new LiveOgmiosProvider({ ogmiosUrl: config.ogmiosUrl });
+}

gateway/src/cli/create-demo-key.ts

@@ -0,0 +1,76 @@
+/**
+ * gateway/src/cli/create-demo-key.ts — mint the shared demo API key.
+ *
+ * Same custodial machinery as POST /signup, but sets demo=1: withdraw is
+ * blocked, /account hides the deposit address, chat completions run through
+ * the session-backed demo executor, and per-IP rate limits apply. Public
+ * signup can never mint a demo key — this CLI is the only path.
+ *
+ * Run inside the gateway container (hits the volume-mounted DB):
+ *   docker exec <gateway> pnpm --filter @marketplace/gateway create-demo-key
+ * Or locally:
+ *   GATEWAY_MASTER_KEY=<64hex> GATEWAY_DB_DIR=./data/gateway NETWORK_ID=1 \
+ *   pnpm --filter @marketplace/gateway create-demo-key [--label shared-demo]
+ *
+ * The raw key is printed ONCE and never stored (only its sha256).
+ */
+
+import { randomBytes, randomUUID } from "crypto";
+import { GatewayStore } from "../db/store.js";
+import { genPrivKeyHex, deriveWalletKey } from "../wallet.js";
+import { seal } from "../crypto/seal.js";
+import { hashApiKey } from "../middleware/apiKeyAuth.js";
+
+const HEX64 = /^[0-9a-fA-F]{64}$/;
+
+function arg(name: string): string | undefined {
+  const i = process.argv.indexOf(`--${name}`);
+  return i >= 0 ? process.argv[i + 1] : undefined;
+}
+
+function main(): void {
+  const masterKey = process.env.GATEWAY_MASTER_KEY;
+  if (!masterKey || !HEX64.test(masterKey)) {
+    throw new Error("create-demo-key: GATEWAY_MASTER_KEY must be 64 hex chars");
+  }
+  const dbDir = arg("db") ?? process.env.GATEWAY_DB_DIR ?? "./data/gateway";
+  const networkId: 0 | 1 = process.env.NETWORK_ID === "1" ? 1 : 0;
+  const label = arg("label") ?? "shared-demo";
+
+  const privHex = genPrivKeyHex();
+  const walletKey = deriveWalletKey(privHex, networkId);
+  const sealed = seal(privHex, masterKey);
+
+  const rawKey = `vk_${networkId === 1 ? "live" : "test"}_${randomBytes(24).toString("hex")}`;
+
+  const store = new GatewayStore(dbDir);
+  store.insertKey({
+    id: randomUUID(),
+    key_hash: hashApiKey(rawKey),
+    key_prefix: rawKey.slice(0, 12),
+    label,
+    wallet_pkh: walletKey.pubKeyHash,
+    deposit_address: walletKey.address,
+    enc_priv_nonce: sealed.nonce,
+    enc_priv_ct: sealed.ct,
+    enc_priv_tag: sealed.tag,
+    master_key_version: 1,
+    created_at: Date.now(),
+    demo: 1,
+  });
+
+  // eslint-disable-next-line no-console
+  console.log(
+    [
+      `[gateway] demo key created (label=${label}, network=${networkId === 1 ? "mainnet" : "testnet"})`,
+      ``,
+      `  api_key:         ${rawKey}`,
+      `  deposit_address: ${walletKey.address}`,
+      ``,
+      `Save the api_key now — it is shown only once. Fund the deposit address`,
+      `with the demo float (withdrawals are disabled for this key).`,
+    ].join("\n"),
+  );
+}
+
+main();

gateway/src/cli/rotate-master-key.ts

@@ -0,0 +1,52 @@
+/**
+ * gateway/src/cli/rotate-master-key.ts — re-encrypt all custodial keys.
+ *
+ * Decrypts every api_keys row with the OLD master key and re-encrypts with the
+ * NEW one, bumping master_key_version. Run with the gateway stopped.
+ *
+ *   GATEWAY_DB_DIR=./data/gateway \
+ *   pnpm --filter @marketplace/gateway rotate-master-key \
+ *     --old <64hex-old> --new <64hex-new>
+ */
+
+import { GatewayStore } from "../db/store.js";
+import { seal, open as unseal } from "../crypto/seal.js";
+
+const HEX64 = /^[0-9a-fA-F]{64}$/;
+
+function arg(name: string): string | undefined {
+  const i = process.argv.indexOf(`--${name}`);
+  return i >= 0 ? process.argv[i + 1] : undefined;
+}
+
+function main(): void {
+  const oldKey = arg("old") ?? process.env.GATEWAY_MASTER_KEY_OLD;
+  const newKey = arg("new") ?? process.env.GATEWAY_MASTER_KEY;
+  const dbDir = arg("db") ?? process.env.GATEWAY_DB_DIR ?? "./data/gateway";
+
+  if (!oldKey || !HEX64.test(oldKey)) throw new Error("rotate: --old must be 64 hex chars");
+  if (!newKey || !HEX64.test(newKey)) throw new Error("rotate: --new must be 64 hex chars");
+  if (oldKey === newKey) throw new Error("rotate: --old and --new are identical");
+
+  const store = new GatewayStore(dbDir);
+  const rows = store.listAllKeys();
+  let rotated = 0;
+  for (const row of rows) {
+    const priv = unseal(
+      { nonce: row.enc_priv_nonce, ct: row.enc_priv_ct, tag: row.enc_priv_tag },
+      oldKey,
+    );
+    const sealed = seal(priv, newKey);
+    store.updateKeyEncryption(row.id, {
+      enc_priv_nonce: sealed.nonce,
+      enc_priv_ct: sealed.ct,
+      enc_priv_tag: sealed.tag,
+      master_key_version: row.master_key_version + 1,
+    });
+    rotated += 1;
+  }
+  // eslint-disable-next-line no-console
+  console.log(`[gateway] rotated ${rotated} key(s) at ${dbDir}; restart the gateway with the NEW GATEWAY_MASTER_KEY.`);
+}
+
+main();

gateway/src/config.ts

@@ -0,0 +1,146 @@
+/**
+ * gateway/src/config.ts — env loading for the OpenAI-compatible gateway.
+ *
+ * Mirrors buyer/src/config.ts conventions (requireField, HEX64_RE, LIVE_CHAIN
+ * semantics) but for a multi-tenant, custodial service. See docs/gateway.md.
+ *
+ * Required:
+ *   GATEWAY_MASTER_KEY  — 64-char hex (32 bytes). AES-256-GCM key wrapping every
+ *                         user's custodial wallet private key at rest. Losing it
+ *                         permanently locks all user funds.
+ *   INDEXER_URL         — internal indexer base URL.
+ *   OGMIOS_URL          — Ogmios HTTP endpoint (required; the gateway submits txs).
+ *
+ * Optional:
+ *   LIVE_CHAIN          — must be "1" (the gateway always needs a live provider).
+ *   NETWORK_ID          — "0" testnet (default) | "1" mainnet.
+ *   GATEWAY_PORT        — default 3010.
+ *   GATEWAY_DB_DIR      — default "./data/gateway".
+ *   SIGNUP_RATE_MAX / SIGNUP_RATE_WINDOW_MS  — per-IP signup limiter.
+ *   KEY_RATE_MAX / KEY_RATE_WINDOW_MS        — per-key request limiter.
+ *   SWEEPER_INTERVAL_MS / WALLET_HEALTH_INTERVAL_MS — background tick cadences.
+ *   SDK_REGISTRY_MAX    — max cached per-key Marketplace instances (LRU).
+ *   GATEWAY_CORS_ORIGINS — comma-separated allowlist of browser Origins that may
+ *                         call the gateway cross-origin (e.g. the marketplace
+ *                         frontend's "Generate API key" page). Default empty =
+ *                         CORS off (no Access-Control-* headers emitted).
+ */
+
+const HEX64_RE = /^[0-9a-fA-F]{64}$/;
+const POS_INT_RE = /^[1-9]\d*$/;
+
+export interface GatewayConfig {
+  masterKeyHex: string;
+  indexerUrl: string;
+  ogmiosUrl: string;
+  networkId: 0 | 1;
+  liveChain: boolean;
+  port: number;
+  dbDir: string;
+  signupRate: { max: number; windowMs: number };
+  keyRate: { max: number; windowMs: number };
+  demoIpRate: { max: number; windowMs: number };
+  sweeperIntervalMs: number;
+  /** Close demo chat sessions idle this long (frees the supplier slot).
+   * Keep below the supplier's CHAT_IDLE_TIMEOUT_MS so the gateway closes
+   * first and records usage. */
+  demoSessionIdleMs: number;
+  /** Chat-session settlement mode this deployment runs. "full" = suppliers
+   * Claim/Submit and the gateway Accepts; "ticket" = the escrow post at open
+   * is the only chain op and the sweeper Reclaims it after deliver_by.
+   * Must agree with the suppliers' CHAT_SETTLE_MODE. */
+  chatSettleMode: "full" | "ticket";
+  walletHealthIntervalMs: number;
+  sdkRegistryMax: number;
+  corsOrigins: string[];
+}
+
+function requireField(env: Record<string, string | undefined>, name: string): string {
+  const v = env[name];
+  if (v === undefined || v === null || v === "") {
+    throw new Error(`loadConfig: missing required env var ${name}`);
+  }
+  return v;
+}
+
+function chatSettleMode(env: Record<string, string | undefined>): "full" | "ticket" {
+  const v = env.CHAT_SETTLE_MODE ?? "full";
+  if (v !== "full" && v !== "ticket") {
+    throw new Error('loadConfig: CHAT_SETTLE_MODE must be "full" or "ticket"');
+  }
+  return v;
+}
+
+function posInt(
+  env: Record<string, string | undefined>,
+  name: string,
+  fallback: number,
+): number {
+  const v = env[name];
+  if (v === undefined || v === "") return fallback;
+  if (!POS_INT_RE.test(v)) {
+    throw new Error(`loadConfig: ${name} must be a positive integer`);
+  }
+  return Number(v);
+}
+
+export function loadConfig(env: Record<string, string | undefined>): GatewayConfig {
+  const masterKeyHex = requireField(env, "GATEWAY_MASTER_KEY");
+  if (!HEX64_RE.test(masterKeyHex)) {
+    throw new Error(
+      "loadConfig: GATEWAY_MASTER_KEY must be 64 hex chars (32 bytes); generate with: openssl rand -hex 32",
+    );
+  }
+
+  const indexerUrl = requireField(env, "INDEXER_URL").replace(/\/+$/, "");
+
+  // The gateway always posts/settles escrows, so a live provider is mandatory.
+  const liveChain = env.LIVE_CHAIN === "1";
+  const ogmiosUrl = env.OGMIOS_URL ?? "";
+  if (!liveChain) {
+    throw new Error("loadConfig: LIVE_CHAIN=1 is required (the gateway submits transactions)");
+  }
+  if (ogmiosUrl === "") {
+    throw new Error("loadConfig: OGMIOS_URL is required when LIVE_CHAIN=1");
+  }
+
+  let networkId: 0 | 1 = 0;
+  const networkIdStr = env.NETWORK_ID;
+  if (networkIdStr !== undefined && networkIdStr !== "") {
+    if (networkIdStr !== "0" && networkIdStr !== "1") {
+      throw new Error('loadConfig: NETWORK_ID must be "0" (testnet) or "1" (mainnet)');
+    }
+    networkId = networkIdStr === "1" ? 1 : 0;
+  }
+
+  return {
+    masterKeyHex,
+    indexerUrl,
+    ogmiosUrl,
+    networkId,
+    liveChain,
+    port: posInt(env, "GATEWAY_PORT", 3010),
+    dbDir: env.GATEWAY_DB_DIR ?? "./data/gateway",
+    signupRate: {
+      max: posInt(env, "SIGNUP_RATE_MAX", 5),
+      windowMs: posInt(env, "SIGNUP_RATE_WINDOW_MS", 60 * 60 * 1000),
+    },
+    keyRate: {
+      max: posInt(env, "KEY_RATE_MAX", 60),
+      windowMs: posInt(env, "KEY_RATE_WINDOW_MS", 60 * 1000),
+    },
+    demoIpRate: {
+      max: posInt(env, "DEMO_IP_RATE_MAX", 20),
+      windowMs: posInt(env, "DEMO_IP_RATE_WINDOW_MS", 60 * 1000),
+    },
+    sweeperIntervalMs: posInt(env, "SWEEPER_INTERVAL_MS", 60 * 1000),
+    demoSessionIdleMs: posInt(env, "DEMO_SESSION_IDLE_MS", 3 * 60 * 1000),
+    chatSettleMode: chatSettleMode(env),
+    walletHealthIntervalMs: posInt(env, "WALLET_HEALTH_INTERVAL_MS", 10 * 60 * 1000),
+    sdkRegistryMax: posInt(env, "SDK_REGISTRY_MAX", 500),
+    corsOrigins: (env.GATEWAY_CORS_ORIGINS ?? "")
+      .split(",")
+      .map((o) => o.trim().replace(/\/+$/, ""))
+      .filter((o) => o !== ""),
+  };
+}

gateway/src/crypto/seal.ts

@@ -0,0 +1,46 @@
+/**
+ * gateway/src/crypto/seal.ts — AES-256-GCM sealing for custodial private keys.
+ *
+ * Each user's wallet private key (64-char hex) is encrypted at rest with the
+ * GATEWAY_MASTER_KEY (32 bytes). A fresh 12-byte nonce per row; the 16-byte GCM
+ * auth tag is stored alongside. Plaintext is produced only in-memory at request
+ * time (open()) and never persisted or logged.
+ */
+
+import { createCipheriv, createDecipheriv, randomBytes } from "crypto";
+
+export interface Sealed {
+  /** 12-byte GCM nonce, hex. */
+  nonce: string;
+  /** ciphertext, hex. */
+  ct: string;
+  /** 16-byte GCM auth tag, hex. */
+  tag: string;
+}
+
+function masterKeyBuffer(masterKeyHex: string): Buffer {
+  const buf = Buffer.from(masterKeyHex, "hex");
+  if (buf.length !== 32) {
+    throw new Error("seal: master key must decode to exactly 32 bytes");
+  }
+  return buf;
+}
+
+/** Encrypt `plaintext` (e.g. a wallet privKey hex) under the master key. */
+export function seal(plaintext: string, masterKeyHex: string): Sealed {
+  const key = masterKeyBuffer(masterKeyHex);
+  const nonce = randomBytes(12);
+  const cipher = createCipheriv("aes-256-gcm", key, nonce);
+  const ct = Buffer.concat([cipher.update(plaintext, "utf8"), cipher.final()]);
+  const tag = cipher.getAuthTag();
+  return { nonce: nonce.toString("hex"), ct: ct.toString("hex"), tag: tag.toString("hex") };
+}
+
+/** Decrypt a Sealed blob under the master key. Throws on tamper / wrong key. */
+export function open(sealed: Sealed, masterKeyHex: string): string {
+  const key = masterKeyBuffer(masterKeyHex);
+  const decipher = createDecipheriv("aes-256-gcm", key, Buffer.from(sealed.nonce, "hex"));
+  decipher.setAuthTag(Buffer.from(sealed.tag, "hex"));
+  const pt = Buffer.concat([decipher.update(Buffer.from(sealed.ct, "hex")), decipher.final()]);
+  return pt.toString("utf8");
+}

gateway/src/db/schema.ts

@@ -0,0 +1,62 @@
+/**
+ * gateway/src/db/schema.ts — SQLite schema for the gateway.
+ *
+ * Three tables:
+ *   api_keys — one custodial wallet per key; the wallet priv is AES-GCM sealed
+ *              (enc_priv_*). The raw API key is NEVER stored — only sha256(key).
+ *   usage    — one row per billable unit (a one-shot completion or a closed chat
+ *              session), for /account spend reporting and audit.
+ *   sessions — open chat sessions (one escrow per session), for streaming turns
+ *              and sweeper recovery of abandoned sessions.
+ */
+
+export const CREATE_TABLES_SQL = `
+CREATE TABLE IF NOT EXISTS api_keys (
+  id                 TEXT PRIMARY KEY,
+  key_hash           TEXT NOT NULL UNIQUE,
+  key_prefix         TEXT NOT NULL,
+  label              TEXT,
+  wallet_pkh         TEXT NOT NULL,
+  deposit_address    TEXT NOT NULL,
+  enc_priv_nonce     TEXT NOT NULL,
+  enc_priv_ct        TEXT NOT NULL,
+  enc_priv_tag       TEXT NOT NULL,
+  master_key_version INTEGER NOT NULL DEFAULT 1,
+  created_at         INTEGER NOT NULL,
+  disabled           INTEGER NOT NULL DEFAULT 0,
+  demo               INTEGER NOT NULL DEFAULT 0
+);
+CREATE INDEX IF NOT EXISTS idx_keys_hash ON api_keys(key_hash);
+
+CREATE TABLE IF NOT EXISTS usage (
+  id                TEXT PRIMARY KEY,
+  key_id            TEXT NOT NULL,
+  created_at        INTEGER NOT NULL,
+  kind              TEXT NOT NULL,
+  model             TEXT,
+  capability_id     TEXT,
+  supplier_pkh      TEXT,
+  escrow_ref        TEXT,
+  cost_lovelace     TEXT,
+  prompt_tokens     INTEGER NOT NULL DEFAULT 0,
+  completion_tokens INTEGER NOT NULL DEFAULT 0,
+  status            TEXT NOT NULL,
+  failure_reason    TEXT
+);
+CREATE INDEX IF NOT EXISTS idx_usage_key ON usage(key_id, created_at DESC);
+
+CREATE TABLE IF NOT EXISTS sessions (
+  id                TEXT PRIMARY KEY,
+  key_id            TEXT NOT NULL,
+  escrow_ref        TEXT NOT NULL,
+  session_nonce     TEXT NOT NULL,
+  supplier_base_url TEXT NOT NULL,
+  supplier_pkh      TEXT NOT NULL,
+  model             TEXT NOT NULL,
+  price_lovelace    TEXT NOT NULL,
+  state             TEXT NOT NULL,
+  opened_at         INTEGER NOT NULL,
+  closed_at         INTEGER
+);
+CREATE INDEX IF NOT EXISTS idx_sessions_key ON sessions(key_id, opened_at DESC);
+`;

gateway/src/db/store.ts

@@ -0,0 +1,209 @@
+/**
+ * gateway/src/db/store.ts — synchronous SQLite store (mirrors buyer/src/db/archive.ts).
+ *
+ * better-sqlite3 + WAL + prepared statements. Low write volume (≤1 row per
+ * request) so synchronous is fine and simpler than async.
+ */
+
+import { mkdirSync } from "fs";
+import { join, resolve } from "path";
+import Database from "better-sqlite3";
+import type { Database as BetterDatabase } from "better-sqlite3";
+import { CREATE_TABLES_SQL } from "./schema.js";
+
+export interface ApiKeyRow {
+  id: string;
+  key_hash: string;
+  key_prefix: string;
+  label: string | null;
+  wallet_pkh: string;
+  deposit_address: string;
+  enc_priv_nonce: string;
+  enc_priv_ct: string;
+  enc_priv_tag: string;
+  master_key_version: number;
+  created_at: number;
+  disabled: number;
+  /** 1 = shared demo key: withdraw blocked, session-backed completions, per-IP limits. */
+  demo: number;
+}
+
+export interface UsageRow {
+  id: string;
+  key_id: string;
+  created_at: number;
+  kind: string;
+  model: string | null;
+  capability_id: string | null;
+  supplier_pkh: string | null;
+  escrow_ref: string | null;
+  cost_lovelace: string | null;
+  prompt_tokens: number;
+  completion_tokens: number;
+  status: string;
+  failure_reason: string | null;
+}
+
+export interface SessionRow {
+  id: string;
+  key_id: string;
+  escrow_ref: string;
+  session_nonce: string;
+  supplier_base_url: string;
+  supplier_pkh: string;
+  model: string;
+  price_lovelace: string;
+  state: string;
+  opened_at: number;
+  closed_at: number | null;
+}
+
+export class GatewayStore {
+  private readonly db: BetterDatabase;
+
+  private readonly sInsertKey;
+  private readonly sGetKeyByHash;
+  private readonly sGetKeyById;
+  private readonly sListKeys;
+  private readonly sListAllKeys;
+  private readonly sUpdateKeyEncryption;
+  private readonly sInsertUsage;
+  private readonly sSumCost;
+  private readonly sCountByKey;
+  private readonly sListUsage;
+  private readonly sInsertSession;
+  private readonly sGetSession;
+  private readonly sSetSessionState;
+  private readonly sListOpenSessions;
+
+  constructor(dbDir: string) {
+    const dir = resolve(dbDir);
+    mkdirSync(dir, { recursive: true });
+    this.db = new Database(join(dir, "gateway.db"));
+    this.db.pragma("journal_mode = WAL");
+    this.db.exec(CREATE_TABLES_SQL);
+
+    // Additive migration for DBs created before the demo flag existed
+    // (CREATE TABLE IF NOT EXISTS won't alter an existing table).
+    const keyCols = this.db.pragma("table_info(api_keys)") as Array<{ name: string }>;
+    if (!keyCols.some((c) => c.name === "demo")) {
+      this.db.exec("ALTER TABLE api_keys ADD COLUMN demo INTEGER NOT NULL DEFAULT 0");
+    }
+
+    this.sInsertKey = this.db.prepare(`
+      INSERT INTO api_keys (
+        id, key_hash, key_prefix, label, wallet_pkh, deposit_address,
+        enc_priv_nonce, enc_priv_ct, enc_priv_tag, master_key_version, created_at, disabled, demo
+      ) VALUES (
+        @id, @key_hash, @key_prefix, @label, @wallet_pkh, @deposit_address,
+        @enc_priv_nonce, @enc_priv_ct, @enc_priv_tag, @master_key_version, @created_at, 0, @demo
+      )
+    `);
+    this.sGetKeyByHash = this.db.prepare(`SELECT * FROM api_keys WHERE key_hash = @key_hash`);
+    this.sGetKeyById = this.db.prepare(`SELECT * FROM api_keys WHERE id = @id`);
+    this.sListKeys = this.db.prepare(`SELECT * FROM api_keys WHERE disabled = 0`);
+    this.sListAllKeys = this.db.prepare(`SELECT * FROM api_keys`);
+    this.sUpdateKeyEncryption = this.db.prepare(`
+      UPDATE api_keys SET enc_priv_nonce = @enc_priv_nonce, enc_priv_ct = @enc_priv_ct,
+        enc_priv_tag = @enc_priv_tag, master_key_version = @master_key_version WHERE id = @id
+    `);
+
+    this.sInsertUsage = this.db.prepare(`
+      INSERT INTO usage (
+        id, key_id, created_at, kind, model, capability_id, supplier_pkh, escrow_ref,
+        cost_lovelace, prompt_tokens, completion_tokens, status, failure_reason
+      ) VALUES (
+        @id, @key_id, @created_at, @kind, @model, @capability_id, @supplier_pkh, @escrow_ref,
+        @cost_lovelace, @prompt_tokens, @completion_tokens, @status, @failure_reason
+      )
+    `);
+    this.sSumCost = this.db.prepare(`
+      SELECT COALESCE(SUM(CAST(cost_lovelace AS INTEGER)), 0) AS total
+      FROM usage WHERE key_id = @key_id AND status = 'completed'
+    `);
+    this.sCountByKey = this.db.prepare(`SELECT COUNT(*) AS n FROM usage WHERE key_id = @key_id`);
+    this.sListUsage = this.db.prepare(`
+      SELECT * FROM usage WHERE key_id = @key_id ORDER BY created_at DESC LIMIT @limit
+    `);
+
+    this.sInsertSession = this.db.prepare(`
+      INSERT INTO sessions (
+        id, key_id, escrow_ref, session_nonce, supplier_base_url, supplier_pkh,
+        model, price_lovelace, state, opened_at, closed_at
+      ) VALUES (
+        @id, @key_id, @escrow_ref, @session_nonce, @supplier_base_url, @supplier_pkh,
+        @model, @price_lovelace, @state, @opened_at, NULL
+      )
+    `);
+    this.sGetSession = this.db.prepare(`SELECT * FROM sessions WHERE id = @id`);
+    this.sSetSessionState = this.db.prepare(`
+      UPDATE sessions SET state = @state, closed_at = @closed_at WHERE id = @id
+    `);
+    this.sListOpenSessions = this.db.prepare(`SELECT * FROM sessions WHERE state = 'open'`);
+  }
+
+  insertKey(row: Omit<ApiKeyRow, "disabled" | "demo"> & { demo?: number }): void {
+    this.sInsertKey.run({ ...row, label: row.label ?? null, demo: row.demo ?? 0 });
+  }
+
+  getKeyByHash(keyHash: string): ApiKeyRow | undefined {
+    return this.sGetKeyByHash.get({ key_hash: keyHash }) as ApiKeyRow | undefined;
+  }
+
+  getKeyById(id: string): ApiKeyRow | undefined {
+    return this.sGetKeyById.get({ id }) as ApiKeyRow | undefined;
+  }
+
+  listKeys(): ApiKeyRow[] {
+    return this.sListKeys.all() as ApiKeyRow[];
+  }
+
+  listAllKeys(): ApiKeyRow[] {
+    return this.sListAllKeys.all() as ApiKeyRow[];
+  }
+
+  updateKeyEncryption(
+    id: string,
+    enc: { enc_priv_nonce: string; enc_priv_ct: string; enc_priv_tag: string; master_key_version: number },
+  ): void {
+    this.sUpdateKeyEncryption.run({ id, ...enc });
+  }
+
+  insertUsage(row: UsageRow): void {
+    this.sInsertUsage.run(row);
+  }
+
+  sumCostLovelace(keyId: string): bigint {
+    const r = this.sSumCost.get({ key_id: keyId }) as { total: number } | undefined;
+    return BigInt(r?.total ?? 0);
+  }
+
+  countUsage(keyId: string): number {
+    const r = this.sCountByKey.get({ key_id: keyId }) as { n: number } | undefined;
+    return r?.n ?? 0;
+  }
+
+  listUsage(keyId: string, limit: number): UsageRow[] {
+    return this.sListUsage.all({ key_id: keyId, limit }) as UsageRow[];
+  }
+
+  insertSession(row: Omit<SessionRow, "closed_at">): void {
+    this.sInsertSession.run(row);
+  }
+
+  getSession(id: string): SessionRow | undefined {
+    return this.sGetSession.get({ id }) as SessionRow | undefined;
+  }
+
+  setSessionState(id: string, state: string, closedAt: number | null): void {
+    this.sSetSessionState.run({ id, state, closed_at: closedAt });
+  }
+
+  listOpenSessions(): SessionRow[] {
+    return this.sListOpenSessions.all() as SessionRow[];
+  }
+
+  listOpenSessionsByKey(keyId: string): SessionRow[] {
+    return this.listOpenSessions().filter((s) => s.key_id === keyId);
+  }
+}

gateway/src/deps.ts

@@ -0,0 +1,16 @@
+/**
+ * gateway/src/deps.ts — shared dependency bundle passed to route factories.
+ */
+
+import type { LiveOgmiosProvider } from "@marketplace/shared/chain";
+import type { GatewayConfig } from "./config.js";
+import type { GatewayStore } from "./db/store.js";
+import type { SdkRegistry } from "./sdk/registry.js";
+
+export interface GatewayDeps {
+  config: GatewayConfig;
+  store: GatewayStore;
+  chain: LiveOgmiosProvider;
+  registry: SdkRegistry;
+  fetchFn: typeof globalThis.fetch;
+}

gateway/src/index.ts

@@ -0,0 +1,70 @@
+/**
+ * gateway/src/index.ts — entry point.
+ *
+ * Wires config → shared chain + store → SdkRegistry → Express app, and starts
+ * the reclaim sweeper + wallet-health ticker. Boot is wrapped in runMain() so
+ * importing this module (tests) does not start the server.
+ */
+
+import { loadConfig } from "./config.js";
+import { buildChainProvider } from "./chain.js";
+import { GatewayStore } from "./db/store.js";
+import { SdkRegistry } from "./sdk/registry.js";
+import { createApp } from "./server.js";
+import { startSweeper } from "./sweeper.js";
+import { startWalletHealthTicker } from "./walletHealth.js";
+import type { GatewayDeps } from "./deps.js";
+
+export function buildDeps(env: Record<string, string | undefined>): GatewayDeps {
+  const config = loadConfig(env);
+  const store = new GatewayStore(config.dbDir);
+  const chain = buildChainProvider(config);
+  const registry = new SdkRegistry({
+    chain,
+    indexerUrl: config.indexerUrl,
+    networkId: config.networkId,
+    masterKeyHex: config.masterKeyHex,
+    max: config.sdkRegistryMax,
+  });
+  return { config, store, chain, registry, fetchFn: globalThis.fetch };
+}
+
+export function runMain(env: Record<string, string | undefined>): void {
+  const deps = buildDeps(env);
+  const app = createApp(deps);
+
+  const stopSweeper = startSweeper(deps);
+  const stopHealth = startWalletHealthTicker(deps);
+
+  const server = app.listen(deps.config.port, () => {
+    // eslint-disable-next-line no-console
+    console.log(
+      `[gateway] listening on :${deps.config.port} (network=${deps.config.networkId}, indexer=${deps.config.indexerUrl})`,
+    );
+  });
+
+  const shutdown = (): void => {
+    // eslint-disable-next-line no-console
+    console.log("[gateway] shutting down...");
+    stopSweeper();
+    stopHealth();
+    server.close(() => process.exit(0));
+  };
+  process.once("SIGINT", shutdown);
+  process.once("SIGTERM", shutdown);
+}
+
+const invokedDirectly =
+  typeof process !== "undefined" &&
+  process.argv?.[1] !== undefined &&
+  /gateway\/(src|dist)\/index\.(t|j)s$/.test(process.argv[1]);
+
+if (invokedDirectly) {
+  try {
+    runMain(process.env);
+  } catch (err) {
+    // eslint-disable-next-line no-console
+    console.error("[gateway] boot failed:", err);
+    process.exit(1);
+  }
+}

gateway/src/middleware/apiKeyAuth.ts

@@ -0,0 +1,45 @@
+/**
+ * gateway/src/middleware/apiKeyAuth.ts — Bearer API-key authentication.
+ *
+ * Looks up sha256(rawKey) in api_keys (unique index). The raw key is never
+ * stored. Attaches the matched row to req.gatewayKey for downstream handlers.
+ */
+
+import { createHash } from "crypto";
+import type { Request, Response, NextFunction } from "express";
+import type { GatewayStore, ApiKeyRow } from "../db/store.js";
+import { unauthorized } from "../openai/errors.js";
+import { sendError } from "./http.js";
+
+export interface GatewayRequest extends Request {
+  gatewayKey?: ApiKeyRow;
+}
+
+export function hashApiKey(raw: string): string {
+  return createHash("sha256").update(raw, "utf8").digest("hex");
+}
+
+export function makeApiKeyAuth(store: GatewayStore) {
+  return (req: Request, res: Response, next: NextFunction): void => {
+    const header = req.header("authorization") ?? "";
+    const m = /^Bearer\s+(.+)$/i.exec(header.trim());
+    if (!m) {
+      sendError(res, unauthorized("missing or malformed Authorization: Bearer header"));
+      return;
+    }
+    const row = store.getKeyByHash(hashApiKey(m[1].trim()));
+    if (!row || row.disabled) {
+      sendError(res, unauthorized());
+      return;
+    }
+    (req as GatewayRequest).gatewayKey = row;
+    next();
+  };
+}
+
+/** Read the authenticated key off the request (throws if middleware missing). */
+export function requireKey(req: Request): ApiKeyRow {
+  const row = (req as GatewayRequest).gatewayKey;
+  if (!row) throw unauthorized();
+  return row;
+}

gateway/src/middleware/http.ts

@@ -0,0 +1,25 @@
+/**
+ * gateway/src/middleware/http.ts — Express response/error helpers.
+ */
+
+import type { Request, Response } from "express";
+import { GatewayError, toGatewayError, toErrorBody } from "../openai/errors.js";
+
+/** Send a GatewayError (or any error) as an OpenAI-shaped JSON error response. */
+export function sendError(res: Response, err: unknown): void {
+  const ge = err instanceof GatewayError ? err : toGatewayError(err);
+  if (res.headersSent) {
+    res.end();
+    return;
+  }
+  res.status(ge.httpStatus).json(toErrorBody(ge));
+}
+
+/** Wrap an async handler so rejections are mapped to error responses. */
+export function asyncHandler(
+  fn: (req: Request, res: Response) => Promise<void>,
+): (req: Request, res: Response) => void {
+  return (req, res) => {
+    fn(req, res).catch((err) => sendError(res, err));
+  };
+}

gateway/src/middleware/rateLimit.ts

@@ -0,0 +1,87 @@
+/**
+ * gateway/src/middleware/rateLimit.ts — per-IP and per-key limiters.
+ *
+ * Small sliding-window limiter (same shape as buyer/src/auth.ts createRateLimiter,
+ * inlined to avoid coupling the operator-auth module into the gateway). Used to
+ * bound public /signup abuse (per IP) and per-key request volume (429 + Retry-After).
+ */
+
+import type { Request, Response, NextFunction } from "express";
+import { rateLimited } from "../openai/errors.js";
+import { sendError } from "./http.js";
+import { requireKey } from "./apiKeyAuth.js";
+
+interface Bucket {
+  count: number;
+  windowStart: number;
+}
+
+interface Limiter {
+  attempt(key: string): { allowed: boolean; retryAfterMs: number };
+}
+
+function createLimiter(opts: { max: number; windowMs: number }): Limiter {
+  const buckets = new Map<string, Bucket>();
+  return {
+    attempt(key: string) {
+      const t = Date.now();
+      const existing = buckets.get(key);
+      if (!existing || t - existing.windowStart >= opts.windowMs) {
+        buckets.set(key, { count: 1, windowStart: t });
+        return { allowed: true, retryAfterMs: 0 };
+      }
+      if (existing.count >= opts.max) {
+        return { allowed: false, retryAfterMs: Math.max(0, opts.windowMs - (t - existing.windowStart)) };
+      }
+      existing.count += 1;
+      return { allowed: true, retryAfterMs: 0 };
+    },
+  };
+}
+
+type Keyer = (req: Request) => string;
+
+function makeLimiter(opts: { max: number; windowMs: number }, keyOf: Keyer) {
+  const limiter = createLimiter(opts);
+  return (req: Request, res: Response, next: NextFunction): void => {
+    const decision = limiter.attempt(keyOf(req));
+    if (!decision.allowed) {
+      const retrySec = Math.ceil(decision.retryAfterMs / 1000);
+      res.setHeader("Retry-After", retrySec.toString());
+      sendError(res, rateLimited(`rate limit exceeded; retry in ${retrySec}s`));
+      return;
+    }
+    next();
+  };
+}
+
+/** Per-IP limiter (for the public /signup endpoint). */
+export function ipRateLimit(opts: { max: number; windowMs: number }) {
+  return makeLimiter(opts, (req) => req.ip ?? "unknown");
+}
+
+/** Per-API-key limiter (apply AFTER apiKeyAuth). Demo keys are exempt: the
+ * shared demo key would let one abusive IP exhaust everyone's budget — the
+ * per-IP demoIpRateLimit is the demo control instead. */
+export function keyRateLimit(opts: { max: number; windowMs: number }) {
+  const limit = makeLimiter(opts, (req) => requireKey(req).id);
+  return (req: Request, res: Response, next: NextFunction): void => {
+    if (requireKey(req).demo) {
+      next();
+      return;
+    }
+    limit(req, res, next);
+  };
+}
+
+/** Per-IP limiter that applies ONLY to demo-key requests (after apiKeyAuth). */
+export function demoIpRateLimit(opts: { max: number; windowMs: number }) {
+  const limit = makeLimiter(opts, (req) => req.ip ?? "unknown");
+  return (req: Request, res: Response, next: NextFunction): void => {
+    if (!requireKey(req).demo) {
+      next();
+      return;
+    }
+    limit(req, res, next);
+  };
+}

gateway/src/onchain/preflight.ts

@@ -0,0 +1,55 @@
+/**
+ * gateway/src/onchain/preflight.ts — balance + collateral pre-flight.
+ *
+ * The buyer wallet funds the FULL escrow at PostEscrow: price + buyer_bond +
+ * supplier_bond (postEscrow.ts:132). Accept/Reclaim are Plutus script-spends
+ * that also need a pure-AP3X collateral UTxO ≥ 5 AP3X (assertCollateralCandidate).
+ * So required = price + buyer_bond + supplier_bond + collateral + fee reserve,
+ * AND the wallet must currently hold a pure-AP3X UTxO ≥ collateral. We check both
+ * up front and return a clean 402 instead of failing mid-flight.
+ */
+
+import type { ChainProvider, Utxo } from "@marketplace/shared/chain";
+
+export const COLLATERAL_MIN_LOVELACE = 5_000_000n;
+export const FEE_RESERVE_LOVELACE = 2_000_000n;
+
+export function totalLovelace(utxos: Utxo[]): bigint {
+  return utxos.reduce((sum, u) => sum + u.lovelace, 0n);
+}
+
+/** True iff some UTxO is pure-AP3X (no native assets) and ≥ collateral floor. */
+export function hasCollateral(utxos: Utxo[]): boolean {
+  return utxos.some(
+    (u) => u.lovelace >= COLLATERAL_MIN_LOVELACE && Object.keys(u.assets).length === 0,
+  );
+}
+
+export interface PreflightResult {
+  ok: boolean;
+  availableLovelace: bigint;
+  requiredLovelace: bigint;
+  collateralOk: boolean;
+}
+
+export async function preflight(
+  chain: ChainProvider,
+  address: string,
+  cost: { priceLovelace: bigint; buyerBondLovelace: bigint; supplierBondLovelace: bigint },
+): Promise<PreflightResult> {
+  const utxos = await chain.queryUtxosByAddress(address);
+  const available = totalLovelace(utxos);
+  const collateralOk = hasCollateral(utxos);
+  const required =
+    cost.priceLovelace +
+    cost.buyerBondLovelace +
+    cost.supplierBondLovelace +
+    COLLATERAL_MIN_LOVELACE +
+    FEE_RESERVE_LOVELACE;
+  return {
+    ok: available >= required && collateralOk,
+    availableLovelace: available,
+    requiredLovelace: required,
+    collateralOk,
+  };
+}

gateway/src/onchain/settle.ts

@@ -0,0 +1,125 @@
+/**
+ * gateway/src/onchain/settle.ts — settlement + recovery helpers.
+ *
+ * submitPrompt returns the ORIGINAL Open escrow ref, but the supplier's
+ * Claim→Submit moves the live escrow to a NEW ref. To Accept (settle) we must
+ * resolve the current Submitted ref via the indexer (mirrors buyer /v1/accept:
+ * match the lineage by posted_at). Because the per-key mutex serializes a
+ * wallet's escrows, at settle time the wallet has at most one in-flight escrow,
+ * so a lone Submitted row is unambiguously ours.
+ *
+ * acceptResult/reclaim on the SDK are fire-and-forget; here we buildAcceptTx /
+ * buildReclaimTx and AWAIT confirmation so a returned success means settled.
+ */
+
+import type { ChainProvider, OutputReference } from "@marketplace/shared/chain";
+import type { WalletKey } from "@marketplace/shared/tx";
+import { buildAcceptTx, buildReclaimTx } from "@marketplace/shared/tx";
+import { parseRef } from "../routing/selectSupplier.js";
+import { GatewayError } from "../openai/errors.js";
+
+export interface EscrowRow {
+  utxo_ref: string;
+  state: string;
+  posted_at: number;
+  /** Validator reclaim floor (indexer serves it; absent on very old rows). */
+  deliver_by?: number;
+}
+
+export async function fetchEscrows(
+  indexerUrl: string,
+  buyerPkh: string,
+  fetchFn: typeof globalThis.fetch,
+): Promise<EscrowRow[]> {
+  const res = await fetchFn(`${indexerUrl}/escrows?buyer=${buyerPkh}`);
+  if (!res.ok) throw new Error(`indexer /escrows returned ${res.status}`);
+  const body = (await res.json()) as unknown;
+  if (!Array.isArray(body)) throw new Error("indexer /escrows did not return an array");
+  return body as EscrowRow[];
+}
+
+function sleep(ms: number): Promise<void> {
+  return new Promise((r) => setTimeout(r, ms));
+}
+
+/** Poll the indexer for the current Submitted UTxO of our in-flight escrow. */
+export async function resolveSubmittedRef(opts: {
+  indexerUrl: string;
+  buyerPkh: string;
+  originalRefStr: string;
+  fetchFn?: typeof globalThis.fetch;
+  timeoutMs?: number;
+  intervalMs?: number;
+}): Promise<OutputReference> {
+  const fetchFn = opts.fetchFn ?? globalThis.fetch;
+  const timeoutMs = opts.timeoutMs ?? 60_000;
+  const intervalMs = opts.intervalMs ?? 2_000;
+  const deadline = Date.now() + timeoutMs;
+
+  let lastErr: unknown;
+  for (;;) {
+    try {
+      const rows = await fetchEscrows(opts.indexerUrl, opts.buyerPkh, fetchFn);
+
+      // 1. Direct: the original ref already shows Submitted.
+      const direct = rows.find((r) => r.utxo_ref === opts.originalRefStr && r.state === "Submitted");
+      if (direct) return refOrThrow(direct.utxo_ref);
+
+      // 2. Lineage: find the original row to read posted_at, then the Submitted
+      //    row sharing it (the validator preserves posted_at across states).
+      const lineage = rows.find((r) => r.utxo_ref === opts.originalRefStr);
+      if (lineage) {
+        const submitted = rows.find((r) => r.posted_at === lineage.posted_at && r.state === "Submitted");
+        if (submitted) return refOrThrow(submitted.utxo_ref);
+      }
+
+      // 3. Fallback: the mutex guarantees ≤1 in-flight escrow for this wallet,
+      //    so a single Submitted row is ours.
+      const submittedRows = rows.filter((r) => r.state === "Submitted");
+      if (submittedRows.length === 1) return refOrThrow(submittedRows[0].utxo_ref);
+    } catch (err) {
+      lastErr = err;
+    }
+    if (Date.now() >= deadline) {
+      throw new GatewayError(
+        502,
+        "server_error",
+        "escrow_settle_failed",
+        `could not resolve Submitted escrow within ${timeoutMs}ms${lastErr ? `: ${String(lastErr)}` : ""}`,
+      );
+    }
+    await sleep(intervalMs);
+  }
+}
+
+function refOrThrow(refStr: string): OutputReference {
+  const ref = parseRef(refStr);
+  if (!ref) {
+    throw new GatewayError(502, "server_error", "escrow_settle_failed", `bad escrow ref ${refStr}`);
+  }
+  return ref;
+}
+
+/** Build + submit + await the Accept tx (Submitted → Accepted, terminal). */
+export async function acceptAndConfirm(
+  chain: ChainProvider,
+  walletKey: WalletKey,
+  escrowRef: OutputReference,
+  awaitTimeoutMs = 120_000,
+): Promise<string> {
+  const built = await buildAcceptTx({ chain, buyerKey: walletKey, escrowRef });
+  await chain.awaitTx(built.expectedTxHash, awaitTimeoutMs);
+  return built.expectedTxHash;
+}
+
+/** Build + submit + await a Reclaim tx (Open/Claimed → Reclaimed). */
+export async function reclaimAndConfirm(
+  chain: ChainProvider,
+  walletKey: WalletKey,
+  escrowRef: OutputReference,
+  awaitTimeoutMs = 120_000,
+): Promise<string> {
+  const built = await buildReclaimTx({ chain, buyerKey: walletKey, escrowRef });
+  await chain.awaitTx(built.expectedTxHash, awaitTimeoutMs);
+  return built.expectedTxHash;
+}

gateway/src/openai/affinity.ts

@@ -0,0 +1,116 @@
+/**
+ * gateway/src/openai/affinity.ts — transcript-prefix session matching.
+ *
+ * Stateless OpenAI clients resend the FULL message history each call; sessions
+ * are stateful. An incoming request belongs to an open session when that
+ * session's mirrored transcript is a prefix of the incoming messages — the
+ * suffix (delta) is the next turn. Client-authored messages (user/system/tool)
+ * must match byte-exactly, but clients routinely reshape ASSISTANT text when
+ * echoing it back (strip <think> reasoning, re-render whitespace), so
+ * assistant content is compared normalized. Strict (byte-exact) matches are
+ * preferred over lenient ones to disambiguate concurrent threads that share a
+ * user-message prefix. The mirror itself is NEVER rewritten with client text:
+ * the delta is forwarded verbatim and mirrored only after a successful turn,
+ * so the gateway mirror and the supplier transcript stay hash-identical for
+ * the receipt response_hash.
+ *
+ * Pure module — no I/O — so the matching rules are unit-testable.
+ */
+
+import { chatMessagesEquivalent, toolCallsEqual, type ChatMessage } from "@marketplace/shared/tx";
+
+export interface AffinityCandidate {
+  sessionId: string;
+  model: string;
+  mirror: ChatMessage[];
+  lastUsedAt: number;
+}
+
+export interface AffinityMatch {
+  sessionId: string;
+  /** Messages the session has not seen yet — forwarded as the next turn. */
+  delta: ChatMessage[];
+}
+
+/** Canonicalize assistant text the way clients mangle it when re-echoing
+ * history: drop <think>…</think> reasoning blocks, collapse whitespace runs,
+ * trim. Exported for tests. */
+export function normalizeAssistantContent(content: string): string {
+  return content
+    .replace(/<think>[\s\S]*?<\/think>/gi, "")
+    .replace(/\s+/g, " ")
+    .trim();
+}
+
+/** Lenient equality: strict for client-authored roles (the client sends the
+ * same bytes both times); assistant content is compared normalized while
+ * assistant tool_calls stay strict (ids anchor tool-result turns). */
+function chatMessagesLenientEquivalent(a: ChatMessage, b: ChatMessage): boolean {
+  if (a.role !== b.role) return false;
+  if (a.role !== "assistant") return chatMessagesEquivalent(a, b);
+  return (
+    normalizeAssistantContent(a.content) === normalizeAssistantContent(b.content) &&
+    toolCallsEqual(a.tool_calls, b.tool_calls)
+  );
+}
+
+type PrefixQuality = "strict" | "lenient";
+
+function classifyPrefix(mirror: ChatMessage[], incoming: ChatMessage[]): PrefixQuality | null {
+  if (mirror.length >= incoming.length) return null;
+  let strict = true;
+  for (let i = 0; i < mirror.length; i++) {
+    if (chatMessagesEquivalent(mirror[i], incoming[i])) continue;
+    if (!chatMessagesLenientEquivalent(mirror[i], incoming[i])) return null;
+    strict = false;
+  }
+  return strict ? "strict" : "lenient";
+}
+
+function deltaRespondable(delta: ChatMessage[]): boolean {
+  const last = delta[delta.length - 1];
+  return last !== undefined && (last.role === "user" || last.role === "tool");
+}
+
+/** Drop trailing assistant/system messages so the history ends with a
+ * respondable message (regenerate semantics for clients that send a trailing
+ * assistant turn). Empty result = nothing to answer. */
+export function trimToRespondable(messages: ChatMessage[]): ChatMessage[] {
+  let end = messages.length;
+  while (end > 0 && messages[end - 1].role !== "user" && messages[end - 1].role !== "tool") end--;
+  return messages.slice(0, end);
+}
+
+/**
+ * Pick the open session whose mirror best matches the incoming history.
+ * Strict prefixes beat lenient ones; then longest mirror wins (most
+ * conversation reuse); ties go to the most recently used session. Returns
+ * null when nothing matches — caller opens a new session and replays the full
+ * history. Note `incoming.length <= mirror.length` never matches (a client
+ * retry of an already-answered request is a miss by design: the session
+ * transcript must stay append-only).
+ */
+export function matchSessionPrefix(
+  candidates: AffinityCandidate[],
+  incoming: ChatMessage[],
+  model: string,
+): AffinityMatch | null {
+  let best: { cand: AffinityCandidate; quality: PrefixQuality } | null = null;
+  for (const cand of candidates) {
+    if (cand.model !== model) continue;
+    const quality = classifyPrefix(cand.mirror, incoming);
+    if (quality === null) continue;
+    if (!deltaRespondable(incoming.slice(cand.mirror.length))) continue;
+    if (
+      best === null ||
+      (quality === "strict" && best.quality === "lenient") ||
+      (quality === best.quality &&
+        (cand.mirror.length > best.cand.mirror.length ||
+          (cand.mirror.length === best.cand.mirror.length && cand.lastUsedAt > best.cand.lastUsedAt)))
+    ) {
+      best = { cand, quality };
+    }
+  }
+  if (!best) return null;
+  return { sessionId: best.cand.sessionId, delta: incoming.slice(best.cand.mirror.length) };
+}

gateway/src/openai/chatCompletions.ts

@@ -0,0 +1,233 @@
+/**
+ * gateway/src/openai/chatCompletions.ts — POST /openai/v1/chat/completions.
+ *
+ * One escrow per call against an llm.text.generate.v1 supplier. Lifecycle (all
+ * inside the per-key mutex): route → preflight → submitPrompt → resolve the
+ * Submitted ref + Accept (awaited) → record usage → wallet-health → respond.
+ * stream:true returns the completion as a buffered pseudo-stream (one delta +
+ * final usage chunk + [DONE]) with keepalive comments during the escrow wait.
+ */
+
+import { randomUUID } from "crypto";
+import type { Request, Response } from "express";
+import { TxConstructionError } from "@marketplace/shared/tx";
+import type { GatewayDeps } from "../deps.js";
+import type { ApiKeyRow, GatewayStore } from "../db/store.js";
+import type { KeyContext } from "../sdk/registry.js";
+import { requireKey } from "../middleware/apiKeyAuth.js";
+import { asyncHandler } from "../middleware/http.js";
+import { selectCandidates } from "../routing/selectSupplier.js";
+import { preflight } from "../onchain/preflight.js";
+import { resolveSubmittedRef, acceptAndConfirm } from "../onchain/settle.js";
+import { ensureWalletHealthy } from "../walletHealth.js";
+import { parseChatRequest, type ParsedChatRequest } from "./validate.js";
+import { runDemoChat } from "./demoChat.js";
+import {
+  genId,
+  buildChatCompletion,
+  buildChunk,
+  usageFromReceipt,
+  sseData,
+  SSE_DONE,
+  type Usage,
+} from "./shapes.js";
+import { notFound, paymentRequired, toGatewayError, toErrorBody } from "./errors.js";
+
+const CAPABILITY = "llm.text.generate.v1";
+
+function recordUsage(
+  store: GatewayStore,
+  p: {
+    keyId: string;
+    model: string;
+    supplierPkh: string | null;
+    escrowRef: string | null;
+    costLovelace: bigint | null;
+    usage: Usage | null;
+    status: "completed" | "failed";
+    failureReason?: string;
+  },
+): void {
+  store.insertUsage({
+    id: randomUUID(),
+    key_id: p.keyId,
+    created_at: Date.now(),
+    kind: "completion",
+    model: p.model,
+    capability_id: CAPABILITY,
+    supplier_pkh: p.supplierPkh,
+    escrow_ref: p.escrowRef,
+    cost_lovelace: p.costLovelace !== null ? p.costLovelace.toString() : null,
+    prompt_tokens: p.usage?.prompt_tokens ?? 0,
+    completion_tokens: p.usage?.completion_tokens ?? 0,
+    status: p.status,
+    failure_reason: p.failureReason ?? null,
+  });
+}
+
+export function makeChatCompletionsHandler(deps: GatewayDeps) {
+  return asyncHandler(async (req: Request, res: Response) => {
+    const keyRow = requireKey(req);
+    const ctx = deps.registry.getContext(keyRow);
+    if (keyRow.demo) {
+      // Demo keys run session-backed with tools passthrough, and never fall
+      // back to one-shot (its settle path assumes ≤1 in-flight escrow per
+      // wallet; the demo wallet holds one escrow per concurrent session).
+      // Not under the key mutex — runDemoChat takes it only for session opens.
+      const parsed = parseChatRequest(req.body, { allowTools: true });
+      await runDemoChat(deps, keyRow, ctx, parsed, res);
+      return;
+    }
+    const parsed = parseChatRequest(req.body);
+    await ctx.mutex.run(() => runOneShot(deps, keyRow, ctx, parsed, res));
+  });
+}
+
+async function runOneShot(
+  deps: GatewayDeps,
+  keyRow: ApiKeyRow,
+  ctx: KeyContext,
+  parsed: ParsedChatRequest,
+  res: Response,
+): Promise<void> {
+  const { config, store, chain, fetchFn } = deps;
+
+  const candidates = await selectCandidates({
+    indexerUrl: config.indexerUrl,
+    model: parsed.model,
+    capabilityId: CAPABILITY,
+    fetchFn,
+  });
+  if (candidates.length === 0) {
+    throw notFound("model_not_found", `no available supplier for model "${parsed.model}"`);
+  }
+
+  const primary = candidates[0];
+  const pf = await preflight(chain, ctx.walletKey.address, primary);
+  if (!pf.ok) {
+    throw paymentRequired(
+      pf.collateralOk
+        ? "insufficient balance for this request"
+        : "wallet has no pure-AP3X UTxO ≥ 5 AP3X for collateral; deposit a little more AP3X",
+      {
+        x_vector: {
+          required_lovelace: pf.requiredLovelace.toString(),
+          available_lovelace: pf.availableLovelace.toString(),
+          collateral_ok: pf.collateralOk,
+          deposit_address: ctx.walletKey.address,
+        },
+      },
+    );
+  }
+
+  const id = genId();
+  let keepalive: ReturnType<typeof setInterval> | undefined;
+  if (parsed.stream) {
+    res.status(200);
+    res.setHeader("Content-Type", "text/event-stream");
+    res.setHeader("Cache-Control", "no-cache, no-transform");
+    res.setHeader("Connection", "keep-alive");
+    res.setHeader("X-Accel-Buffering", "no");
+    res.write(": connected\n\n");
+    keepalive = setInterval(() => {
+      try {
+        res.write(": keepalive\n\n");
+      } catch {
+        /* client gone */
+      }
+    }, 10_000);
+  }
+
+  try {
+    // Submit. Fall back to the next supplier ONLY on a pre-post
+    // TxConstructionError (no escrow was posted). A SupplierError means the
+    // escrow is already posted — do not retry (the sweeper recovers it).
+    let result: Awaited<ReturnType<typeof ctx.sdk.submitPrompt>> | undefined;
+    let used: (typeof candidates)[number] | undefined;
+    let lastErr: unknown;
+    for (const cand of candidates) {
+      try {
+        result = await ctx.sdk.submitPrompt({
+          advertRef: cand.advertRef,
+          messages: parsed.messages,
+          payment_lovelace: cand.priceLovelace,
+          max_output_tokens: parsed.maxTokens,
+        });
+        used = cand;
+        break;
+      } catch (err) {
+        lastErr = err;
+        if (err instanceof TxConstructionError) continue;
+        throw err;
+      }
+    }
+    if (!result || !used) {
+      throw toGatewayError(lastErr ?? new Error("no supplier could be engaged"));
+    }
+
+    // Settle: resolve the live Submitted ref, Accept, await confirmation.
+    const originalRefStr = `${result.escrowRef.txHash}#${result.escrowRef.index}`;
+    const submittedRef = await resolveSubmittedRef({
+      indexerUrl: config.indexerUrl,
+      buyerPkh: ctx.walletKey.pubKeyHash,
+      originalRefStr,
+      fetchFn,
+    });
+    await acceptAndConfirm(chain, ctx.walletKey, submittedRef);
+
+    const usage = usageFromReceipt(result.receipt);
+    const vector = {
+      receipt: result.receipt,
+      receipt_signature: result.receiptSignature,
+      escrow_ref: originalRefStr,
+    };
+    recordUsage(store, {
+      keyId: keyRow.id,
+      model: parsed.model,
+      supplierPkh: used.supplierPkh,
+      escrowRef: originalRefStr,
+      costLovelace: used.priceLovelace,
+      usage,
+      status: "completed",
+    });
+
+    // Re-shape the wallet ({collateral, working}) so the next request keeps a
+    // valid collateral UTxO. Best-effort; serialized by the mutex.
+    await ensureWalletHealthy(chain, ctx.walletKey).catch((e) =>
+      // eslint-disable-next-line no-console
+      console.error("[gateway] wallet-health after completion:", e instanceof Error ? e.message : e),
+    );
+
+    if (parsed.stream) {
+      if (keepalive) clearInterval(keepalive);
+      res.write(sseData(buildChunk({ id, model: parsed.model, delta: { role: "assistant", content: result.response }, finishReason: null })));
+      res.write(sseData(buildChunk({ id, model: parsed.model, delta: {}, finishReason: "stop", usage, vector })));
+      res.write(SSE_DONE);
+      res.end();
+    } else {
+      res.status(200).json(buildChatCompletion({ id, model: parsed.model, content: result.response, usage, vector }));
+    }
+  } catch (err) {
+    if (keepalive) clearInterval(keepalive);
+    recordUsage(store, {
+      keyId: keyRow.id,
+      model: parsed.model,
+      supplierPkh: null,
+      escrowRef: null,
+      costLovelace: null,
+      usage: null,
+      status: "failed",
+      failureReason: err instanceof Error ? err.message : String(err),
+    });
+    if (parsed.stream && res.headersSent) {
+      try {
+        res.write(sseData(toErrorBody(toGatewayError(err))));
+      } catch {
+        /* client gone */
+      }
+      res.end();
+      return;
+    }
+    throw err;
+  }
+}

gateway/src/openai/demoChat.ts

@@ -0,0 +1,413 @@
+/**
+ * gateway/src/openai/demoChat.ts — session-backed /chat/completions for the
+ * shared demo key.
+ *
+ * Demo requests keep the standard OpenAI wire shape (tools included) but run
+ * against real escrow-per-session marketplace conversations: transcript-prefix
+ * affinity maps each stateless request onto an open session and forwards only
+ * the unseen delta; a miss transparently opens a new session (escrow post —
+ * the only chain work, under the key mutex) and replays the full history as
+ * the first turn. Supplier idle-closes are healed by reopening; the sweeper
+ * settles the abandoned escrow.
+ *
+ * Demo keys NEVER fall back to the one-shot path: resolveSubmittedRef's
+ * lone-Submitted-row fallback assumes ≤1 in-flight escrow per wallet, and the
+ * demo wallet holds one escrow per concurrent session.
+ */
+
+import { randomUUID } from "crypto";
+import type { Response } from "express";
+import type { ChatMessage, ToolCall } from "@marketplace/shared/tx";
+import type { GatewayDeps } from "../deps.js";
+import type { ApiKeyRow, SessionRow } from "../db/store.js";
+import type { KeyContext } from "../sdk/registry.js";
+import { transcripts, getSessionLock, dropSessionState } from "./transcripts.js";
+import { matchSessionPrefix, trimToRespondable, type AffinityCandidate } from "./affinity.js";
+import {
+  CAPABILITY,
+  SessionGoneError,
+  openSessionCore,
+  streamSupplierTurn,
+  type TurnResult,
+} from "./sessions.js";
+import type { ParsedChatRequest } from "./validate.js";
+import { genId, buildChatCompletion, buildChunk, sseData, SSE_DONE, type Usage } from "./shapes.js";
+import { GatewayError, badRequest, toGatewayError, toErrorBody } from "./errors.js";
+
+interface DemoSessionMeta {
+  keyId: string;
+  model: string;
+  lastUsedAt: number;
+}
+
+/** Open sessions owned by the demo executor (sessionId → meta). Mirrors live
+ * in transcripts.ts; this map scopes affinity to demo-opened sessions. */
+const demoSessions = new Map<string, DemoSessionMeta>();
+
+/** Forget a session (closed/settled elsewhere, e.g. by the sweeper). */
+export function dropDemoSession(sessionId: string): void {
+  demoSessions.delete(sessionId);
+}
+
+function candidatesFor(keyId: string, model: string): AffinityCandidate[] {
+  const out: AffinityCandidate[] = [];
+  for (const [sessionId, meta] of demoSessions) {
+    if (meta.keyId !== keyId || meta.model !== model) continue;
+    const mirror = transcripts.get(sessionId);
+    if (!mirror) continue;
+    out.push({ sessionId, model: meta.model, mirror, lastUsedAt: meta.lastUsedAt });
+  }
+  return out;
+}
+
+/** Record the session's cost when the demo executor closes its row. Full
+ * mode: the flat session fee (supplier Submitted; the sweeper Accepts the
+ * escrow afterwards). Ticket mode: 0 — nothing settles, the sweeper reclaims
+ * the escrow and the wallet is made whole minus fees. */
+function recordSessionCost(deps: GatewayDeps, session: SessionRow): void {
+  deps.store.insertUsage({
+    id: randomUUID(),
+    key_id: session.key_id,
+    created_at: Date.now(),
+    kind: "chat_session",
+    model: session.model,
+    capability_id: CAPABILITY,
+    supplier_pkh: session.supplier_pkh,
+    escrow_ref: session.escrow_ref,
+    cost_lovelace: deps.config.chatSettleMode === "ticket" ? "0" : session.price_lovelace,
+    prompt_tokens: 0,
+    completion_tokens: 0,
+    status: "completed",
+    failure_reason: null,
+  });
+}
+
+function markSessionGone(deps: GatewayDeps, session: SessionRow): void {
+  deps.store.setSessionState(session.id, "closed", Date.now());
+  dropSessionState(session.id);
+  dropDemoSession(session.id);
+  recordSessionCost(deps, session);
+}
+
+/** Ask the supplier to settle (Submit) the session. NO gateway chain work —
+ * the sweeper Accepts the resulting Submitted escrow. The supplier releases
+ * its single slot as part of ending, so a truthy return means the supplier is
+ * free again. Best-effort: on failure the sweeper reclaims later. */
+async function requestSupplierEnd(deps: GatewayDeps, session: SessionRow): Promise<boolean> {
+  try {
+    const res = await deps.fetchFn(`${session.supplier_base_url.replace(/\/+$/, "")}/v1/chat/end`, {
+      method: "POST",
+      headers: { "content-type": "application/json", "X-Escrow-Ref": session.escrow_ref },
+      body: JSON.stringify({}),
+      signal: AbortSignal.timeout(90_000),
+    });
+    await res.text().catch(() => "");
+    return res.ok;
+  } catch {
+    return false;
+  }
+}
+
+/** Close one demo session (evicted for capacity, or idle-janitored). Runs
+ * under the session lock so an in-flight turn finishes first; takes NO key
+ * mutex (no chain work here — see requestSupplierEnd). Returns the freed
+ * supplier_pkh, or null when the session was already gone or (janitor) was
+ * used again while we waited for the lock. */
+async function closeDemoSession(
+  deps: GatewayDeps,
+  sessionId: string,
+  opts: { reason: "evicted" | "idle"; idleCutoffMs?: number; nowMs?: number },
+): Promise<string | null> {
+  if (!demoSessions.has(sessionId)) return null;
+  return getSessionLock(sessionId).run(async () => {
+    const meta = demoSessions.get(sessionId);
+    if (!meta) return null; // lost a race with another closer
+    // Re-check idleness inside the lock: a turn that won the lock first has
+    // bumped lastUsedAt past the sweep's reference clock.
+    if (opts.idleCutoffMs !== undefined && (opts.nowMs ?? Date.now()) - meta.lastUsedAt < opts.idleCutoffMs) {
+      return null;
+    }
+    const session = deps.store.getSession(sessionId);
+    if (!session || session.state !== "open") {
+      dropDemoSession(sessionId);
+      return null;
+    }
+    await requestSupplierEnd(deps, session);
+    markSessionGone(deps, session);
+    // eslint-disable-next-line no-console
+    console.log(`[gateway:demo] closed session ${sessionId} (${opts.reason}), freed supplier ${session.supplier_pkh}`);
+    return session.supplier_pkh;
+  });
+}
+
+/** Least-recently-used open demo session for (key, model), excluding prior
+ * victims. Same-model scoping doubles as a guard: a bogus model name has no
+ * demo sessions, so eviction can never loop on a genuine model_not_found. */
+function pickLruDemoSession(keyId: string, model: string, exclude: ReadonlySet<string>): string | null {
+  let lruId: string | null = null;
+  let lruAt = Infinity;
+  for (const [sessionId, meta] of demoSessions) {
+    if (meta.keyId !== keyId || meta.model !== model || exclude.has(sessionId)) continue;
+    if (meta.lastUsedAt < lruAt) {
+      lruAt = meta.lastUsedAt;
+      lruId = sessionId;
+    }
+  }
+  return lruId;
+}
+
+/** Close demo sessions idle past deps.config.demoSessionIdleMs so abandoned
+ * conversations (client gone, title-gen one-offs) release their single-slot
+ * suppliers. Called from the sweeper tick; sequential to keep supplier
+ * /v1/chat/end calls orderly. */
+export async function sweepIdleDemoSessions(deps: GatewayDeps, nowMs = Date.now()): Promise<void> {
+  const idleMs = deps.config.demoSessionIdleMs;
+  for (const [sessionId, meta] of [...demoSessions]) {
+    if (nowMs - meta.lastUsedAt < idleMs) continue;
+    try {
+      await closeDemoSession(deps, sessionId, { reason: "idle", idleCutoffMs: idleMs, nowMs });
+    } catch (err) {
+      // eslint-disable-next-line no-console
+      console.error(`[gateway:demo] idle close of ${sessionId} failed:`, err instanceof Error ? err.message : err);
+    }
+  }
+}
+
+const MAX_EVICTIONS = 2;
+
+function isNoSupplierError(err: unknown): boolean {
+  return err instanceof GatewayError && (err.code === "model_not_found" || err.code === "overloaded");
+}
+
+/** Open a session, evicting up to MAX_EVICTIONS LRU demo sessions when every
+ * supplier is pinned. Eviction frees the supplier immediately (its slot
+ * releases at Submit) but the indexer's status poll lags, so the retry passes
+ * the freed pkhs through selectCandidates' ignoreStatusFor. Lock ordering is
+ * safe: eviction holds only the session lock, the open holds only the key
+ * mutex — never nested. */
+async function openSessionWithEviction(
+  deps: GatewayDeps,
+  keyRow: ApiKeyRow,
+  ctx: KeyContext,
+  model: string,
+): Promise<SessionRow> {
+  const freedPkhs = new Set<string>();
+  const evicted = new Set<string>();
+  for (let attempt = 0; ; attempt++) {
+    try {
+      return await ctx.mutex.run(() =>
+        openSessionCore(deps, keyRow, ctx, model, freedPkhs.size > 0 ? { ignoreStatusFor: freedPkhs } : undefined),
+      );
+    } catch (err) {
+      if (attempt >= MAX_EVICTIONS || !isNoSupplierError(err)) throw err;
+      const victimId = pickLruDemoSession(keyRow.id, model, evicted);
+      if (!victimId) throw err;
+      evicted.add(victimId);
+      const pkh = await closeDemoSession(deps, victimId, { reason: "evicted" });
+      if (!pkh) throw err; // nothing actually freed — don't loop
+      freedPkhs.add(pkh);
+    }
+  }
+}
+
+type LockedTurnOutcome =
+  | { kind: "done"; result: TurnResult }
+  | { kind: "retry" } // candidate no longer valid — re-run the match
+  | { kind: "gone" }; // supplier lost the session — open a fresh one
+
+/** Streaming sink shared across turn attempts on one response. */
+interface StreamSink {
+  onToken: (token: string) => void;
+  emitToolCalls: (toolCalls: ToolCall[]) => void;
+}
+
+export async function runDemoChat(
+  deps: GatewayDeps,
+  keyRow: ApiKeyRow,
+  ctx: KeyContext,
+  parsed: ParsedChatRequest,
+  res: Response,
+): Promise<void> {
+  // Clients sometimes send histories ending in an assistant (continue/retry
+  // flows) or system message; the chat.v1 supplier can only respond to a
+  // user/tool-terminated turn. Trim trailing unrespondable messages
+  // (regenerate semantics) and reject — before any chain work — only when
+  // nothing respondable remains.
+  const trimmed = trimToRespondable(parsed.messages);
+  if (trimmed.length === 0) {
+    throw badRequest("invalid_messages", "no user or tool message to respond to");
+  }
+  const effective: ParsedChatRequest =
+    trimmed.length === parsed.messages.length ? parsed : { ...parsed, messages: trimmed };
+
+  const id = genId();
+  let keepalive: ReturnType<typeof setInterval> | undefined;
+  let roleSent = false;
+  if (parsed.stream) {
+    res.status(200);
+    res.setHeader("Content-Type", "text/event-stream");
+    res.setHeader("Cache-Control", "no-cache, no-transform");
+    res.setHeader("Connection", "keep-alive");
+    res.setHeader("X-Accel-Buffering", "no");
+    res.write(": connected\n\n");
+    keepalive = setInterval(() => {
+      try {
+        res.write(": keepalive\n\n");
+      } catch {
+        /* client gone */
+      }
+    }, 10_000);
+  }
+
+  const ensureRole = (): void => {
+    if (roleSent) return;
+    roleSent = true;
+    res.write(sseData(buildChunk({ id, model: parsed.model, delta: { role: "assistant" }, finishReason: null })));
+  };
+  const sink: StreamSink = {
+    onToken: (token) => {
+      if (!parsed.stream) return;
+      ensureRole();
+      res.write(sseData(buildChunk({ id, model: parsed.model, delta: { content: token }, finishReason: null })));
+    },
+    emitToolCalls: (toolCalls) => {
+      if (!parsed.stream) return;
+      ensureRole();
+      res.write(
+        sseData(
+          buildChunk({
+            id,
+            model: parsed.model,
+            delta: { tool_calls: toolCalls.map((tc, index) => ({ index, ...tc })) },
+            finishReason: null,
+          }),
+        ),
+      );
+    },
+  };
+
+  try {
+    const result = await runWithAffinity(deps, keyRow, ctx, effective, sink);
+    if (keepalive) clearInterval(keepalive);
+
+    const usage: Usage = {
+      prompt_tokens: result.usage.prompt_tokens,
+      completion_tokens: result.usage.completion_tokens,
+      total_tokens: result.usage.prompt_tokens + result.usage.completion_tokens,
+    };
+    if (parsed.stream) {
+      if (result.assistantMessage.tool_calls?.length) sink.emitToolCalls(result.assistantMessage.tool_calls);
+      ensureRole();
+      res.write(sseData(buildChunk({ id, model: parsed.model, delta: {}, finishReason: result.finishReason, usage })));
+      res.write(SSE_DONE);
+      res.end();
+    } else {
+      res.status(200).json(
+        buildChatCompletion({
+          id,
+          model: parsed.model,
+          content: result.assistantMessage.content,
+          toolCalls: result.assistantMessage.tool_calls,
+          finishReason: result.finishReason,
+          usage,
+        }),
+      );
+    }
+  } catch (err) {
+    if (keepalive) clearInterval(keepalive);
+    if (parsed.stream && res.headersSent) {
+      try {
+        res.write(sseData(toErrorBody(toGatewayError(err))));
+      } catch {
+        /* client gone */
+      }
+      res.end();
+      return;
+    }
+    throw err;
+  }
+}
+
+async function runWithAffinity(
+  deps: GatewayDeps,
+  keyRow: ApiKeyRow,
+  ctx: KeyContext,
+  parsed: ParsedChatRequest,
+  sink: StreamSink,
+): Promise<TurnResult> {
+  // Affinity: try matching sessions until one serves the turn. The match runs
+  // synchronously (no await between match and lock acquire, so the candidate
+  // set can't shift underneath us); the prefix is re-checked inside the lock
+  // because a concurrent request may have advanced the session first.
+  for (let attempt = 0; attempt < 3; attempt++) {
+    const match = matchSessionPrefix(candidatesFor(keyRow.id, parsed.model), parsed.messages, parsed.model);
+    if (!match) break;
+
+    const outcome: LockedTurnOutcome = await getSessionLock(match.sessionId).run(async () => {
+      const meta = demoSessions.get(match.sessionId);
+      const mirror = transcripts.get(match.sessionId);
+      const session = deps.store.getSession(match.sessionId);
+      if (!meta || !mirror || !session || session.state !== "open") {
+        dropDemoSession(match.sessionId);
+        return { kind: "retry" };
+      }
+      const recheck = matchSessionPrefix(
+        [{ sessionId: session.id, model: meta.model, mirror, lastUsedAt: meta.lastUsedAt }],
+        parsed.messages,
+        parsed.model,
+      );
+      if (!recheck) return { kind: "retry" };
+
+      try {
+        const result = await streamSupplierTurn(
+          deps,
+          session,
+          { messages: recheck.delta, tools: parsed.tools, tool_choice: parsed.toolChoice },
+          sink.onToken,
+        );
+        meta.lastUsedAt = Date.now();
+        return { kind: "done", result };
+      } catch (err) {
+        if (err instanceof SessionGoneError) {
+          // Supplier idle-closed (or restarted). Close our row, record the
+          // fee (the escrow settles via the sweeper) and reopen fresh.
+          markSessionGone(deps, session);
+          return { kind: "gone" };
+        }
+        throw err;
+      }
+    });
+
+    if (outcome.kind === "done") return outcome.result;
+    if (outcome.kind === "gone") break;
+    // retry: candidate vanished/advanced — re-match against current state.
+  }
+
+  // Miss: open a new session (chain work → key mutex; evicts an LRU demo
+  // session when every supplier is pinned) and replay the full history as its
+  // first turn.
+  const session = await openSessionWithEviction(deps, keyRow, ctx, parsed.model);
+  demoSessions.set(session.id, { keyId: keyRow.id, model: parsed.model, lastUsedAt: Date.now() });
+  return getSessionLock(session.id).run(async () => {
+    try {
+      const result = await streamSupplierTurn(
+        deps,
+        session,
+        { messages: parsed.messages, tools: parsed.tools, tool_choice: parsed.toolChoice },
+        sink.onToken,
+      );
+      // Refresh recency after the (possibly long) first stream so this live
+      // thread isn't the LRU/janitor's first victim.
+      const meta = demoSessions.get(session.id);
+      if (meta) meta.lastUsedAt = Date.now();
+      return result;
+    } catch (err) {
+      if (err instanceof SessionGoneError) {
+        // Freshly opened yet already gone (supplier crashed mid-claim).
+        // Surface as an upstream error rather than looping.
+        markSessionGone(deps, session);
+      }
+      throw err;
+    }
+  });
+}

gateway/src/openai/errors.ts

@@ -0,0 +1,78 @@
+/**
+ * gateway/src/openai/errors.ts — OpenAI-shaped error taxonomy.
+ *
+ * OpenAI SDKs parse error.type to drive retry/severity, so every gateway error
+ * is mapped to a concrete {message, type, code} triple and the documented HTTP
+ * status. Marketplace SDK errors (SupplierError/IndexerError/ReceiptVerification
+ * Error) and TxConstructionError are translated here.
+ */
+
+import { ReceiptVerificationError, IndexerError, SupplierError } from "@marketplace/buyer/sdk";
+import { TxConstructionError } from "@marketplace/shared/tx";
+
+export type OpenAiErrorType =
+  | "invalid_request_error"
+  | "authentication_error"
+  | "rate_limit_error"
+  | "server_error";
+
+export class GatewayError extends Error {
+  constructor(
+    public readonly httpStatus: number,
+    public readonly type: OpenAiErrorType,
+    public readonly code: string,
+    message: string,
+    /** Optional vendor extension fields merged alongside `error` in the body. */
+    public readonly extra?: Record<string, unknown>,
+  ) {
+    super(message);
+    this.name = "GatewayError";
+  }
+}
+
+export const badRequest = (code: string, message: string): GatewayError =>
+  new GatewayError(400, "invalid_request_error", code, message);
+export const unauthorized = (message = "invalid API key"): GatewayError =>
+  new GatewayError(401, "authentication_error", "invalid_api_key", message);
+export const paymentRequired = (message: string, extra?: Record<string, unknown>): GatewayError =>
+  new GatewayError(402, "invalid_request_error", "insufficient_funds", message, extra);
+export const forbidden = (code: string, message: string): GatewayError =>
+  new GatewayError(403, "invalid_request_error", code, message);
+export const notFound = (code: string, message: string): GatewayError =>
+  new GatewayError(404, "invalid_request_error", code, message);
+export const rateLimited = (message: string): GatewayError =>
+  new GatewayError(429, "rate_limit_error", "rate_limit_exceeded", message);
+
+/** Render the body OpenAI clients expect: {error:{message,type,code,param}}. */
+export function toErrorBody(err: GatewayError): Record<string, unknown> {
+  return {
+    error: { message: err.message, type: err.type, code: err.code, param: null },
+    ...(err.extra ?? {}),
+  };
+}
+
+/** Map any thrown value to a GatewayError. */
+export function toGatewayError(err: unknown): GatewayError {
+  if (err instanceof GatewayError) return err;
+
+  if (err instanceof SupplierError) {
+    if (err.reason === "timeout") {
+      return new GatewayError(504, "server_error", "supplier_timeout", "supplier timed out");
+    }
+    if (err.reason === "supplier_busy") {
+      return new GatewayError(503, "server_error", "overloaded", "all matching suppliers are busy");
+    }
+    return new GatewayError(502, "server_error", "upstream_error", `supplier error: ${err.reason}`);
+  }
+  if (err instanceof ReceiptVerificationError) {
+    return new GatewayError(502, "server_error", "receipt_verification_failed", `receipt invalid: ${err.reason}`);
+  }
+  if (err instanceof IndexerError) {
+    return new GatewayError(502, "server_error", "indexer_error", `indexer error: ${err.reason}`);
+  }
+  if (err instanceof TxConstructionError) {
+    return new GatewayError(502, "server_error", "escrow_failed", `escrow build failed: ${err.reason}`);
+  }
+  const message = err instanceof Error ? err.message : String(err);
+  return new GatewayError(500, "server_error", "internal_error", message);
+}

gateway/src/openai/models.ts

@@ -0,0 +1,26 @@
+/**
+ * gateway/src/openai/models.ts — GET /openai/v1/models.
+ *
+ * Distinct models advertised by Active suppliers, in the OpenAI list shape.
+ */
+
+import type { Request, Response } from "express";
+import type { GatewayDeps } from "../deps.js";
+import { asyncHandler } from "../middleware/http.js";
+import { requireKey } from "../middleware/apiKeyAuth.js";
+import { listModels } from "../routing/selectSupplier.js";
+import { buildModelsList } from "./shapes.js";
+import { CAPABILITY as CHAT_CAPABILITY } from "./sessions.js";
+
+export function makeModelsHandler(deps: GatewayDeps) {
+  return asyncHandler(async (req: Request, res: Response) => {
+    const keyRow = requireKey(req);
+    // Demo keys only reach chat-capable suppliers (session-backed executor).
+    const models = await listModels({
+      indexerUrl: deps.config.indexerUrl,
+      capabilityId: keyRow.demo ? CHAT_CAPABILITY : undefined,
+      fetchFn: deps.fetchFn,
+    });
+    res.status(200).json(buildModelsList(models));
+  });
+}

gateway/src/openai/sessions.ts

@@ -0,0 +1,479 @@
+/**
+ * gateway/src/openai/sessions.ts — chat sessions (Vector extension).
+ *
+ * One escrow per SESSION (fixed price locked at open, settled at close). Real
+ * token streaming per turn against an llm.chat.v1 supplier. Endpoints:
+ *   POST /openai/v1/chat/sessions            → open  (startChat)
+ *   POST /openai/v1/chat/sessions/:id/messages → one streamed turn
+ *   POST /openai/v1/chat/sessions/:id/close  → settle (endChat: Submit+Accept)
+ *
+ * The chat.v1 supplier has no system-role channel and accumulates the transcript
+ * server-side, so we send one user `content` per turn and mirror the transcript
+ * in-memory (for endChat's response_hash verification). A process restart loses
+ * the mirror; an abandoned session is reclaimed by the sweeper.
+ */
+
+import { randomUUID } from "crypto";
+import type { Request, Response } from "express";
+import { TxConstructionError, normalizeChatMessage, type ChatMessage } from "@marketplace/shared/tx";
+import { SupplierError } from "@marketplace/buyer/sdk";
+import { transcripts, getSessionLock, dropSessionState } from "./transcripts.js";
+import type { GatewayDeps } from "../deps.js";
+import type { ApiKeyRow, GatewayStore, SessionRow } from "../db/store.js";
+import type { KeyContext } from "../sdk/registry.js";
+import { requireKey } from "../middleware/apiKeyAuth.js";
+import { asyncHandler } from "../middleware/http.js";
+import { selectCandidates, parseRef } from "../routing/selectSupplier.js";
+import { preflight } from "../onchain/preflight.js";
+import { ensureWalletHealthy } from "../walletHealth.js";
+import { badRequest, notFound, paymentRequired, toGatewayError, toErrorBody } from "./errors.js";
+import {
+  genId,
+  nowSec,
+  buildChatCompletion,
+  buildChunk,
+  sseData,
+  SSE_DONE,
+  type Usage,
+} from "./shapes.js";
+
+export const CAPABILITY = "llm.chat.v1";
+
+/** Thrown when the supplier no longer knows the session (idle-closed/restart). */
+export class SessionGoneError extends Error {
+  constructor(sessionId: string) {
+    super(`supplier no longer has session ${sessionId}`);
+    this.name = "SessionGoneError";
+  }
+}
+
+function refStr(ref: { txHash: string; index: number }): string {
+  return `${ref.txHash}#${ref.index}`;
+}
+
+// ─── open ──────────────────────────────────────────────────────────────────
+
+export function makeOpenSessionHandler(deps: GatewayDeps) {
+  return asyncHandler(async (req: Request, res: Response) => {
+    const keyRow = requireKey(req);
+    const body = (req.body ?? {}) as Record<string, unknown>;
+    const model = body.model;
+    if (typeof model !== "string" || model === "") {
+      throw badRequest("invalid_model", "`model` is required");
+    }
+    const ctx = deps.registry.getContext(keyRow);
+    const session = await ctx.mutex.run(() => openSessionCore(deps, keyRow, ctx, model));
+    res.status(200).json({ id: session.id, object: "chat.session", model, created: nowSec() });
+  });
+}
+
+/**
+ * Select a supplier, preflight the wallet, post+claim the session escrow and
+ * persist the SessionRow. Chain work — the CALLER must hold the key mutex
+ * (concurrent PostEscrow from one wallet double-spends the same UTxO).
+ */
+export async function openSessionCore(
+  deps: GatewayDeps,
+  keyRow: ApiKeyRow,
+  ctx: KeyContext,
+  model: string,
+  opts?: { ignoreStatusFor?: ReadonlySet<string> },
+): Promise<SessionRow> {
+  const candidates = await selectCandidates({
+    indexerUrl: deps.config.indexerUrl,
+    model,
+    capabilityId: CAPABILITY,
+    fetchFn: deps.fetchFn,
+    ignoreStatusFor: opts?.ignoreStatusFor,
+  });
+  if (candidates.length === 0) {
+    throw notFound("model_not_found", `no available chat (llm.chat.v1) supplier for model "${model}"`);
+  }
+  const primary = candidates[0];
+  const pf = await preflight(deps.chain, ctx.walletKey.address, primary);
+  if (!pf.ok) {
+    throw paymentRequired(
+      pf.collateralOk ? "insufficient balance to open a session" : "wallet has no ≥5 AP3X pure-AP3X collateral UTxO",
+      {
+        x_vector: {
+          required_lovelace: pf.requiredLovelace.toString(),
+          available_lovelace: pf.availableLovelace.toString(),
+          collateral_ok: pf.collateralOk,
+          deposit_address: ctx.walletKey.address,
+        },
+      },
+    );
+  }
+
+  // startChat posts the escrow + supplier Claim. Fall back to the next supplier
+  // only on a pre-post error (TxConstructionError, or a busy supplier caught by
+  // startChat's /status pre-check before any funds are locked).
+  let started: Awaited<ReturnType<typeof ctx.sdk.startChat>> | undefined;
+  let used: (typeof candidates)[number] | undefined;
+  let lastErr: unknown;
+  for (const cand of candidates) {
+    try {
+      started = await ctx.sdk.startChat({ advertRef: cand.advertRef, payment_lovelace: cand.priceLovelace });
+      used = cand;
+      break;
+    } catch (err) {
+      lastErr = err;
+      if (err instanceof TxConstructionError) continue;
+      if (err instanceof SupplierError && err.reason === "supplier_busy") continue;
+      throw err;
+    }
+  }
+  if (!started || !used) throw toGatewayError(lastErr ?? new Error("no chat supplier could be engaged"));
+
+  // Deployment sanity: supplier and gateway must agree on the settle mode.
+  // Close behavior is driven per-session by the supplier's /end response, so
+  // a mismatch (rollout window) still settles correctly — just warn.
+  if ((started.settleMode === "ticket") !== (deps.config.chatSettleMode === "ticket")) {
+    // eslint-disable-next-line no-console
+    console.warn(
+      `[gateway] settle-mode mismatch: supplier ${used.supplierPkh.slice(0, 8)} ran "${started.settleMode}" but gateway is configured "${deps.config.chatSettleMode}"`,
+    );
+  }
+
+  const sessionId = randomUUID();
+  deps.store.insertSession({
+    id: sessionId,
+    key_id: keyRow.id,
+    escrow_ref: refStr(started.escrowRef),
+    session_nonce: started.sessionNonce,
+    supplier_base_url: started.supplierBaseUrl,
+    supplier_pkh: used.supplierPkh,
+    model,
+    price_lovelace: used.priceLovelace.toString(),
+    state: "open",
+    opened_at: Date.now(),
+  });
+  transcripts.set(sessionId, []);
+
+  const session = deps.store.getSession(sessionId);
+  if (!session) throw new Error(`session ${sessionId} vanished after insert`);
+  return session;
+}
+
+// ─── messages (one streamed turn) ────────────────────────────────────────────
+
+export function makeSessionMessageHandler(deps: GatewayDeps) {
+  return asyncHandler(async (req: Request, res: Response) => {
+    const keyRow = requireKey(req);
+    const session = loadOwnedSession(deps.store, req, keyRow);
+    if (session.state !== "open") {
+      throw badRequest("session_closed", `session ${session.id} is ${session.state}`);
+    }
+    const body = (req.body ?? {}) as Record<string, unknown>;
+    const stream = body.stream !== false; // sessions default to streaming
+    const content = resolveTurnContent(session.id, body);
+    if (content === "") throw badRequest("content_required", "no user content in this turn");
+
+    // Turns are chain-free (one HTTP POST to the supplier + SSE relay), so the
+    // per-key mutex — which exists to serialize wallet UTxO spends — is NOT
+    // held here. What needs serialization is this session's transcript:
+    // concurrent turns would interleave supplier appends and corrupt both the
+    // mirror and the receipt hash. Hence a per-session lock.
+    await getSessionLock(session.id).run(() => streamTurn(deps, session, content, stream, res));
+  });
+}
+
+function resolveTurnContent(sessionId: string, body: Record<string, unknown>): string {
+  if (typeof body.content === "string") {
+    return foldSystem(sessionId, body.content, body);
+  }
+  if (Array.isArray(body.messages)) {
+    const msgs = body.messages as Array<{ role?: unknown; content?: unknown }>;
+    const lastUser = [...msgs].reverse().find((m) => m.role === "user" && typeof m.content === "string");
+    const userContent = typeof lastUser?.content === "string" ? lastUser.content : "";
+    return foldSystem(sessionId, userContent, body);
+  }
+  return "";
+}
+
+/** On the first turn only, prepend any system message (chat.v1 has no system channel). */
+function foldSystem(sessionId: string, content: string, body: Record<string, unknown>): string {
+  const mirror = transcripts.get(sessionId) ?? [];
+  if (mirror.length > 0) return content;
+  if (Array.isArray(body.messages)) {
+    const sys = (body.messages as Array<{ role?: unknown; content?: unknown }>)
+      .filter((m) => m.role === "system" && typeof m.content === "string")
+      .map((m) => m.content as string)
+      .join("\n\n");
+    if (sys) return `System: ${sys}\n\n${content}`;
+  }
+  return content;
+}
+
+/** One turn's payload to the supplier: legacy single user string, or a
+ * multi-message delta (e.g. tool results) with optional tools passthrough. */
+export type TurnPayload =
+  | { content: string }
+  | { messages: ChatMessage[]; tools?: unknown[]; tool_choice?: unknown };
+
+export interface TurnResult {
+  assistantMessage: ChatMessage;
+  finishReason: "stop" | "tool_calls";
+  usage: { prompt_tokens: number; completion_tokens: number };
+}
+
+/**
+ * Drive one off-chain turn against the session's supplier and mirror the
+ * result into the session transcript. Caller must hold the session lock.
+ * Throws SessionGoneError when the supplier no longer knows the session
+ * (idle-closed or restarted) so callers can transparently reopen.
+ */
+export async function streamSupplierTurn(
+  deps: GatewayDeps,
+  session: SessionRow,
+  payload: TurnPayload,
+  onToken?: (token: string) => void,
+): Promise<TurnResult> {
+  const upstream = await deps.fetchFn(`${session.supplier_base_url.replace(/\/+$/, "")}/v1/chat/message`, {
+    method: "POST",
+    headers: { "content-type": "application/json", accept: "text/event-stream", "X-Escrow-Ref": session.escrow_ref },
+    body: JSON.stringify(payload),
+  });
+  if (upstream.status === 404) {
+    await upstream.text().catch(() => "");
+    throw new SessionGoneError(session.id);
+  }
+  if (!upstream.ok || !upstream.body) {
+    const detail = await upstream.text().catch(() => "");
+    throw toGatewayError(new SupplierError("supplier_http_error", { status: upstream.status, message: detail.slice(0, 200) }));
+  }
+
+  let assistant = "";
+  let errored: string | undefined;
+  let doneMessage: ChatMessage | null = null;
+  let doneFinish: string | undefined;
+  let usage = { prompt_tokens: 0, completion_tokens: 0 };
+  await readSupplierSse(upstream.body as ReadableStream<Uint8Array>, (frame) => {
+    if (frame.type === "token" && typeof frame.value === "string") {
+      assistant += frame.value;
+      onToken?.(frame.value);
+    } else if (frame.type === "done") {
+      // Upgraded suppliers echo the final assistant message verbatim; mirror
+      // that exact object so both transcripts stay hash-identical.
+      doneMessage = normalizeChatMessage(frame.message);
+      if (typeof frame.finish_reason === "string") doneFinish = frame.finish_reason;
+      if (frame.usage && typeof frame.usage === "object") {
+        const u = frame.usage as Record<string, unknown>;
+        usage = {
+          prompt_tokens: typeof u.prompt_tokens === "number" ? u.prompt_tokens : 0,
+          completion_tokens: typeof u.completion_tokens === "number" ? u.completion_tokens : 0,
+        };
+      }
+    } else if (frame.type === "error") {
+      errored = typeof frame.message === "string" ? frame.message : "supplier stream error";
+    }
+  });
+
+  if (errored !== undefined) {
+    throw toGatewayError(new SupplierError("upstream_error", { message: errored }));
+  }
+
+  const assistantMessage: ChatMessage = doneMessage ?? { role: "assistant", content: assistant };
+  const finishReason: TurnResult["finishReason"] =
+    doneFinish === "tool_calls" || (assistantMessage.tool_calls?.length ?? 0) > 0 ? "tool_calls" : "stop";
+
+  // Mirror the turn for endChat's response_hash verification / affinity matching.
+  const mirror = transcripts.get(session.id) ?? [];
+  if ("content" in payload) mirror.push({ role: "user", content: payload.content });
+  else mirror.push(...payload.messages);
+  mirror.push(assistantMessage);
+  transcripts.set(session.id, mirror);
+
+  return { assistantMessage, finishReason, usage };
+}
+
+async function streamTurn(
+  deps: GatewayDeps,
+  session: SessionRow,
+  content: string,
+  stream: boolean,
+  res: Response,
+): Promise<void> {
+  const id = genId();
+
+  if (stream) {
+    res.status(200);
+    res.setHeader("Content-Type", "text/event-stream");
+    res.setHeader("Cache-Control", "no-cache, no-transform");
+    res.setHeader("Connection", "keep-alive");
+    res.setHeader("X-Accel-Buffering", "no");
+    res.write(sseData(buildChunk({ id, model: session.model, delta: { role: "assistant" }, finishReason: null })));
+  }
+
+  let result: TurnResult;
+  try {
+    result = await streamSupplierTurn(deps, session, { content }, (token) => {
+      if (stream) res.write(sseData(buildChunk({ id, model: session.model, delta: { content: token }, finishReason: null })));
+    });
+  } catch (err) {
+    if (err instanceof SessionGoneError) {
+      err = toGatewayError(new SupplierError("supplier_http_error", { status: 404, message: err.message }));
+    }
+    if (stream) {
+      res.write(sseData(toErrorBody(toGatewayError(err))));
+      res.end();
+      return;
+    }
+    throw toGatewayError(err);
+  }
+
+  if (stream) {
+    res.write(sseData(buildChunk({ id, model: session.model, delta: {}, finishReason: result.finishReason })));
+    res.write(SSE_DONE);
+    res.end();
+  } else {
+    const usage: Usage = {
+      prompt_tokens: result.usage.prompt_tokens,
+      completion_tokens: result.usage.completion_tokens,
+      total_tokens: result.usage.prompt_tokens + result.usage.completion_tokens,
+    };
+    res.status(200).json(buildChatCompletion({ id, model: session.model, content: result.assistantMessage.content, usage }));
+  }
+}
+
+interface SupplierFrame {
+  type?: string;
+  value?: string;
+  message?: unknown;
+  finish_reason?: unknown;
+  usage?: unknown;
+}
+
+/** Read a supplier SSE stream of {type:token|done|error} frames. */
+async function readSupplierSse(
+  body: ReadableStream<Uint8Array>,
+  onFrame: (frame: SupplierFrame) => void,
+): Promise<void> {
+  const reader = body.getReader();
+  const decoder = new TextDecoder();
+  let buf = "";
+  for (;;) {
+    const { value, done } = await reader.read();
+    if (done) break;
+    buf += decoder.decode(value, { stream: true });
+    let sep: number;
+    while ((sep = buf.indexOf("\n\n")) !== -1) {
+      const raw = buf.slice(0, sep);
+      buf = buf.slice(sep + 2);
+      for (const line of raw.split("\n")) {
+        const trimmed = line.trim();
+        if (!trimmed.startsWith("data:")) continue;
+        const data = trimmed.slice(5).trim();
+        if (data === "" || data === "[DONE]") continue;
+        try {
+          onFrame(JSON.parse(data) as SupplierFrame);
+        } catch {
+          /* ignore non-JSON keepalive/comment frames */
+        }
+      }
+    }
+  }
+}
+
+// ─── close (settle) ──────────────────────────────────────────────────────────
+
+export function makeCloseSessionHandler(deps: GatewayDeps) {
+  return asyncHandler(async (req: Request, res: Response) => {
+    const keyRow = requireKey(req);
+    const session = loadOwnedSession(deps.store, req, keyRow);
+    if (session.state !== "open") {
+      throw badRequest("session_closed", `session ${session.id} is already ${session.state}`);
+    }
+    const ctx = deps.registry.getContext(keyRow);
+    await ctx.mutex.run(() => closeSession(deps, keyRow, ctx, session, res));
+  });
+}
+
+async function closeSession(
+  deps: GatewayDeps,
+  keyRow: ApiKeyRow,
+  ctx: KeyContext,
+  session: SessionRow,
+  res: Response,
+): Promise<void> {
+  const escrowRef = parseRef(session.escrow_ref);
+  if (!escrowRef) throw badRequest("bad_session", "session has an invalid escrow ref");
+
+  const result = await ctx.sdk.endChat({
+    escrowRef,
+    sessionNonce: session.session_nonce,
+    supplierBaseUrl: session.supplier_base_url,
+    transcript: transcripts.get(session.id),
+  });
+
+  deps.store.setSessionState(session.id, "closed", Date.now());
+  dropSessionState(session.id);
+
+  if (result.settleMode === "ticket") {
+    // Nothing was Submitted/Accepted: no receipt, no charge (the escrow
+    // returns via the sweeper's reclaim), and no wallet churn to tidy up.
+    deps.store.insertUsage({
+      id: randomUUID(),
+      key_id: keyRow.id,
+      created_at: Date.now(),
+      kind: "chat_session",
+      model: session.model,
+      capability_id: CAPABILITY,
+      supplier_pkh: session.supplier_pkh,
+      escrow_ref: session.escrow_ref,
+      cost_lovelace: "0",
+      prompt_tokens: 0,
+      completion_tokens: 0,
+      status: "completed",
+      failure_reason: null,
+    });
+    res.status(200).json({
+      status: "ended",
+      escrow_ref: session.escrow_ref,
+      settle_mode: "ticket",
+      model: session.model,
+    });
+    return;
+  }
+
+  const prompt = result.receipt.prompt_tokens ?? 0;
+  const completion = result.receipt.completion_tokens ?? 0;
+  deps.store.insertUsage({
+    id: randomUUID(),
+    key_id: keyRow.id,
+    created_at: Date.now(),
+    kind: "chat_session",
+    model: session.model,
+    capability_id: CAPABILITY,
+    supplier_pkh: session.supplier_pkh,
+    escrow_ref: session.escrow_ref,
+    cost_lovelace: session.price_lovelace,
+    prompt_tokens: prompt,
+    completion_tokens: completion,
+    status: "completed",
+    failure_reason: null,
+  });
+
+  await ensureWalletHealthy(deps.chain, ctx.walletKey).catch((e) =>
+    // eslint-disable-next-line no-console
+    console.error("[gateway] wallet-health after session close:", e instanceof Error ? e.message : e),
+  );
+
+  res.status(200).json({
+    status: "closed",
+    escrow_ref: session.escrow_ref,
+    accepted_ref: refStr(result.acceptedRef),
+    model: session.model,
+    x_vector: { receipt: result.receipt, receipt_signature: result.receiptSignature, escrow_ref: session.escrow_ref },
+  });
+}
+
+function loadOwnedSession(store: GatewayStore, req: Request, keyRow: ApiKeyRow): SessionRow {
+  const raw = (req.params as Record<string, string | string[] | undefined>).id;
+  const id = typeof raw === "string" ? raw : undefined;
+  const session = id ? store.getSession(id) : undefined;
+  if (!session || session.key_id !== keyRow.id) {
+    throw notFound("session_not_found", `no chat session ${id ?? "(none)"}`);
+  }
+  return session;
+}

gateway/src/openai/shapes.ts

@@ -0,0 +1,115 @@
+/**
+ * gateway/src/openai/shapes.ts — OpenAI response object builders.
+ *
+ * Produces spec-clean ChatCompletion / ChatCompletionChunk / model-list objects
+ * plus the `x_vector` receipt extension. SSE helpers frame chunks for streaming.
+ */
+
+import { randomBytes } from "crypto";
+import type { Receipt } from "@marketplace/shared/receipt";
+import type { ToolCall } from "@marketplace/shared/tx";
+
+export function genId(): string {
+  return `chatcmpl-${randomBytes(16).toString("hex")}`;
+}
+
+export function nowSec(): number {
+  return Math.floor(Date.now() / 1000);
+}
+
+export interface VectorReceipt {
+  receipt: Receipt;
+  receipt_signature: string;
+  escrow_ref: string;
+}
+
+export interface Usage {
+  prompt_tokens: number;
+  completion_tokens: number;
+  total_tokens: number;
+}
+
+export function usageFromReceipt(receipt: Receipt): Usage {
+  const prompt = receipt.prompt_tokens ?? 0;
+  const completion = receipt.completion_tokens ?? 0;
+  return { prompt_tokens: prompt, completion_tokens: completion, total_tokens: prompt + completion };
+}
+
+/** Non-streaming chat.completion object. */
+export function buildChatCompletion(args: {
+  id: string;
+  model: string;
+  content: string;
+  usage: Usage;
+  toolCalls?: ToolCall[];
+  finishReason?: "stop" | "tool_calls";
+  vector?: VectorReceipt;
+}): Record<string, unknown> {
+  return {
+    id: args.id,
+    object: "chat.completion",
+    created: nowSec(),
+    model: args.model,
+    choices: [
+      {
+        index: 0,
+        message: {
+          role: "assistant",
+          content: args.content,
+          ...(args.toolCalls?.length ? { tool_calls: args.toolCalls } : {}),
+        },
+        finish_reason: args.finishReason ?? "stop",
+      },
+    ],
+    usage: args.usage,
+    ...(args.vector ? { x_vector: args.vector } : {}),
+  };
+}
+
+/** A streaming chat.completion.chunk. `delta` is the incremental content (or {}). */
+export function buildChunk(args: {
+  id: string;
+  model: string;
+  delta:
+    | { role?: string; content?: string; tool_calls?: Array<{ index: number } & ToolCall> }
+    | Record<string, never>;
+  finishReason: "stop" | "tool_calls" | null;
+  usage?: Usage;
+  vector?: VectorReceipt;
+}): Record<string, unknown> {
+  return {
+    id: args.id,
+    object: "chat.completion.chunk",
+    created: nowSec(),
+    model: args.model,
+    choices: [{ index: 0, delta: args.delta, finish_reason: args.finishReason }],
+    ...(args.usage ? { usage: args.usage } : {}),
+    ...(args.vector ? { x_vector: args.vector } : {}),
+  };
+}
+
+/** Frame any object as an SSE `data:` event. */
+export function sseData(obj: unknown): string {
+  return `data: ${JSON.stringify(obj)}\n\n`;
+}
+
+export const SSE_DONE = "data: [DONE]\n\n";
+
+export function buildModelsList(models: string[]): Record<string, unknown> {
+  const created = nowSec();
+  return {
+    object: "list",
+    data: models.map((id) => ({ id, object: "model", created, owned_by: "vector-marketplace" })),
+  };
+}
+
+/** Render OpenAI messages[] into a single prompt string for the chat.v1 session
+ * supplier (which has no system-role channel — see docs/gateway.md). */
+export function renderMessages(messages: Array<{ role: string; content: string }>): string {
+  return messages
+    .map((m) => {
+      const role = m.role === "assistant" ? "Assistant" : m.role === "system" ? "System" : "User";
+      return `${role}: ${m.content}`;
+    })
+    .join("\n\n");
+}

gateway/src/openai/transcripts.ts

@@ -0,0 +1,35 @@
+/**
+ * gateway/src/openai/transcripts.ts — in-memory per-session state shared by
+ * the session routes (sessions.ts), the demo affinity executor (demoChat.ts)
+ * and the sweeper's housekeeping.
+ *
+ * transcripts: mirror of each open session's transcript (sessionId → messages).
+ *   Kept hash-identical to the supplier's authoritative transcript (endChat's
+ *   response_hash check). Lost on restart — abandoned sessions are recovered
+ *   by the supplier idle watchdog + gateway sweeper.
+ * sessionLocks: per-session Mutex serializing turns on ONE session (concurrent
+ *   turns would interleave supplier transcript appends). Distinct from the
+ *   per-key Mutex, which only serializes on-chain wallet work.
+ */
+
+import type { ChatMessage } from "@marketplace/shared/tx";
+import { Mutex } from "../sdk/registry.js";
+
+export const transcripts = new Map<string, ChatMessage[]>();
+
+const sessionLocks = new Map<string, Mutex>();
+
+export function getSessionLock(sessionId: string): Mutex {
+  let lock = sessionLocks.get(sessionId);
+  if (!lock) {
+    lock = new Mutex();
+    sessionLocks.set(sessionId, lock);
+  }
+  return lock;
+}
+
+/** Forget all in-memory state for a session (closed/gone). */
+export function dropSessionState(sessionId: string): void {
+  transcripts.delete(sessionId);
+  sessionLocks.delete(sessionId);
+}

gateway/src/openai/validate.ts

@@ -0,0 +1,88 @@
+/**
+ * gateway/src/openai/validate.ts — request body validation for chat endpoints.
+ */
+
+import { normalizeChatMessage, type ChatMessage } from "@marketplace/shared/tx";
+import { badRequest } from "./errors.js";
+
+export interface ParsedChatRequest {
+  model: string;
+  messages: ChatMessage[];
+  maxTokens?: number;
+  stream: boolean;
+  tools?: unknown[];
+  toolChoice?: unknown;
+}
+
+const ROLES = new Set(["system", "user", "assistant"]);
+
+/** Validate an OpenAI chat.completions-style body. Default path rejects
+ * tools/functions; `allowTools` (demo keys) accepts tools/tool_choice, the
+ * `tool` role, null content and assistant tool_calls, normalizing every
+ * message into canonical mirror shape. Silently ignores temperature/n/stop/
+ * top_p/etc (documented). */
+export function parseChatRequest(body: unknown, opts?: { allowTools?: boolean }): ParsedChatRequest {
+  const allowTools = opts?.allowTools === true;
+  if (typeof body !== "object" || body === null) {
+    throw badRequest("invalid_body", "request body must be a JSON object");
+  }
+  const b = body as Record<string, unknown>;
+
+  if (!allowTools && ("tools" in b || "tool_choice" in b || "functions" in b || "function_call" in b)) {
+    throw badRequest("unsupported_parameter", "tools and function-calling are not supported by this gateway");
+  }
+  if (allowTools && ("functions" in b || "function_call" in b)) {
+    throw badRequest("unsupported_parameter", "legacy functions/function_call are not supported; use tools");
+  }
+
+  const model = b.model;
+  if (typeof model !== "string" || model === "") {
+    throw badRequest("invalid_model", "`model` is required and must be a non-empty string");
+  }
+
+  const rawMessages = b.messages;
+  if (!Array.isArray(rawMessages) || rawMessages.length === 0) {
+    throw badRequest("invalid_messages", "`messages` is required and must be a non-empty array");
+  }
+  const messages: ChatMessage[] = [];
+  for (const m of rawMessages) {
+    if (allowTools) {
+      const msg = normalizeChatMessage(m);
+      if (!msg) {
+        throw badRequest("invalid_messages", "each message must be OpenAI-shaped {role, content, tool_calls?, tool_call_id?}");
+      }
+      messages.push(msg);
+      continue;
+    }
+    if (
+      typeof m !== "object" ||
+      m === null ||
+      typeof (m as { role?: unknown }).role !== "string" ||
+      typeof (m as { content?: unknown }).content !== "string" ||
+      !ROLES.has((m as { role: string }).role)
+    ) {
+      throw badRequest("invalid_messages", "each message must be {role: system|user|assistant, content: string}");
+    }
+    const mm = m as { role: "system" | "user" | "assistant"; content: string };
+    messages.push({ role: mm.role, content: mm.content });
+  }
+
+  let tools: unknown[] | undefined;
+  let toolChoice: unknown;
+  if (allowTools && Array.isArray(b.tools) && b.tools.length > 0) {
+    tools = b.tools;
+    toolChoice = b.tool_choice;
+  }
+
+  let maxTokens: number | undefined;
+  const mt = b.max_tokens ?? b.max_completion_tokens;
+  if (mt !== undefined && mt !== null) {
+    if (typeof mt !== "number" || !Number.isInteger(mt) || mt <= 0) {
+      throw badRequest("invalid_max_tokens", "`max_tokens` must be a positive integer");
+    }
+    maxTokens = mt;
+  }
+
+  const stream = b.stream === true;
+  return { model, messages, maxTokens, stream, tools, toolChoice };
+}

gateway/src/routing/selectSupplier.ts

@@ -0,0 +1,134 @@
+/**
+ * gateway/src/routing/selectSupplier.ts — capability + model routing.
+ *
+ * Queries the indexer for suppliers advertising the requested model under the
+ * required capability. Per the design: match by capability + model, pick an
+ * AVAILABLE supplier (status free|unknown), NOT the cheapest. We return all
+ * eligible candidates so the caller can fall back to the next one when the
+ * chosen supplier turns out to be busy/offline at escrow-post time.
+ *
+ * `status==="unknown"` is treated as eligible: the indexer poller (~20s) leaves
+ * freshly-advertised suppliers as "unknown" until first polled, and excluding
+ * them would create artificial availability gaps.
+ */
+
+import type { OutputReference } from "@marketplace/shared/chain";
+
+/** Subset of the indexer's SupplierView we depend on. */
+interface SupplierView {
+  utxo_ref: string;
+  supplier_pkh: string;
+  capability_id: string;
+  model: string;
+  max_output_tokens: number;
+  price_lovelace: string;
+  supplier_bond_lovelace: string;
+  buyer_bond_lovelace: string;
+  endpoint_url: string;
+  advert_status: string;
+  status: string;
+}
+
+export interface SupplierCandidate {
+  advertRef: OutputReference;
+  utxoRef: string;
+  supplierPkh: string;
+  model: string;
+  capabilityId: string;
+  endpointUrl: string;
+  priceLovelace: bigint;
+  buyerBondLovelace: bigint;
+  supplierBondLovelace: bigint;
+  maxOutputTokens: number;
+  status: string;
+}
+
+const ESCROW_REF_RE = /^([0-9a-fA-F]{64})#(\d+)$/;
+
+export function parseRef(ref: string): OutputReference | null {
+  const m = ESCROW_REF_RE.exec(ref);
+  if (!m) return null;
+  return { txHash: m[1], index: Number(m[2]) };
+}
+
+export interface SelectSupplierOpts {
+  indexerUrl: string;
+  model: string;
+  capabilityId: string;
+  fetchFn?: typeof globalThis.fetch;
+  /** supplier_pkhs eligible regardless of polled status — used after the demo
+   * executor frees a supplier the indexer poller (~20 s cadence) still reports
+   * busy. sdk.startChat's live /status pre-check still guards genuinely-busy
+   * suppliers. */
+  ignoreStatusFor?: ReadonlySet<string>;
+}
+
+/**
+ * Return eligible candidates for (model, capability), ordered for fallback.
+ * Eligible = advert Active, model matches, live status ∈ {free, unknown}.
+ */
+export async function selectCandidates(opts: SelectSupplierOpts): Promise<SupplierCandidate[]> {
+  const fetchFn = opts.fetchFn ?? globalThis.fetch;
+  const url = `${opts.indexerUrl}/suppliers?capability_id=${encodeURIComponent(opts.capabilityId)}`;
+  const res = await fetchFn(url);
+  if (!res.ok) {
+    throw new Error(`indexer /suppliers returned ${res.status}`);
+  }
+  const body = (await res.json()) as unknown;
+  if (!Array.isArray(body)) {
+    throw new Error("indexer /suppliers did not return an array");
+  }
+
+  const candidates: SupplierCandidate[] = [];
+  for (const raw of body as SupplierView[]) {
+    if (raw.capability_id !== opts.capabilityId) continue;
+    if (raw.model !== opts.model) continue;
+    if (raw.advert_status !== "Active") continue;
+    if (raw.status !== "free" && raw.status !== "unknown" && !opts.ignoreStatusFor?.has(raw.supplier_pkh)) {
+      continue;
+    }
+    const advertRef = parseRef(raw.utxo_ref);
+    if (!advertRef) continue;
+    candidates.push({
+      advertRef,
+      utxoRef: raw.utxo_ref,
+      supplierPkh: raw.supplier_pkh,
+      model: raw.model,
+      capabilityId: raw.capability_id,
+      endpointUrl: raw.endpoint_url,
+      priceLovelace: BigInt(raw.price_lovelace),
+      buyerBondLovelace: BigInt(raw.buyer_bond_lovelace),
+      supplierBondLovelace: BigInt(raw.supplier_bond_lovelace),
+      maxOutputTokens: raw.max_output_tokens,
+      status: raw.status,
+    });
+  }
+  // Prefer known-free over unknown so we route to confirmed-available first.
+  candidates.sort((a, b) => (a.status === "free" ? 0 : 1) - (b.status === "free" ? 0 : 1));
+  return candidates;
+}
+
+/** Distinct models across Active suppliers (for GET /openai/v1/models).
+ * Pass capabilityId to list only models under one capability (demo keys see
+ * only llm.chat.v1 models — the session-backed executor's routing target). */
+export async function listModels(opts: {
+  indexerUrl: string;
+  capabilityId?: string;
+  fetchFn?: typeof globalThis.fetch;
+}): Promise<string[]> {
+  const fetchFn = opts.fetchFn ?? globalThis.fetch;
+  const url = opts.capabilityId
+    ? `${opts.indexerUrl}/suppliers?capability_id=${encodeURIComponent(opts.capabilityId)}`
+    : `${opts.indexerUrl}/suppliers`;
+  const res = await fetchFn(url);
+  if (!res.ok) throw new Error(`indexer /suppliers returned ${res.status}`);
+  const body = (await res.json()) as unknown;
+  if (!Array.isArray(body)) throw new Error("indexer /suppliers did not return an array");
+  const models = new Set<string>();
+  for (const raw of body as SupplierView[]) {
+    if (raw.advert_status !== "Active" || typeof raw.model !== "string") continue;
+    if (opts.capabilityId !== undefined && raw.capability_id !== opts.capabilityId) continue;
+    models.add(raw.model);
+  }
+  return [...models].sort();
+}

gateway/src/sdk/registry.ts

@@ -0,0 +1,89 @@
+/**
+ * gateway/src/sdk/registry.ts — per-API-key Marketplace SDK cache + serializer.
+ *
+ * Each API key is its own custodial wallet, so each gets its own Marketplace
+ * instance bound to that wallet's WalletKey. The shared ChainProvider and
+ * indexer URL are reused across all keys. A per-key Mutex serializes all
+ * on-chain work for one wallet (a single wallet cannot post two escrows from
+ * the same UTxO concurrently). The cache is LRU-bounded to cap memory.
+ */
+
+import { Marketplace, MemoryTaskHistoryStore } from "@marketplace/buyer/sdk";
+import type { LiveOgmiosProvider } from "@marketplace/shared/chain";
+import type { WalletKey } from "@marketplace/shared/tx";
+import { open as unseal } from "../crypto/seal.js";
+import { deriveWalletKey } from "../wallet.js";
+import type { ApiKeyRow } from "../db/store.js";
+
+/** Tiny promise-chain mutex: run(fn) executes fns strictly one at a time. */
+export class Mutex {
+  private tail: Promise<unknown> = Promise.resolve();
+
+  run<T>(fn: () => Promise<T>): Promise<T> {
+    const result = this.tail.then(fn, fn);
+    // Keep the chain alive even if fn rejects; swallow here so the next
+    // run() isn't poisoned by a prior rejection.
+    this.tail = result.then(
+      () => undefined,
+      () => undefined,
+    );
+    return result;
+  }
+}
+
+export interface KeyContext {
+  sdk: Marketplace;
+  mutex: Mutex;
+  walletKey: WalletKey;
+}
+
+export interface SdkRegistryDeps {
+  chain: LiveOgmiosProvider;
+  indexerUrl: string;
+  networkId: 0 | 1;
+  masterKeyHex: string;
+  max: number;
+}
+
+export class SdkRegistry {
+  private readonly cache = new Map<string, KeyContext>();
+
+  constructor(private readonly deps: SdkRegistryDeps) {}
+
+  /** Build (or fetch from cache) the per-key SDK context. Decrypts the wallet
+   * key in-memory only when first constructing the instance. */
+  getContext(keyRow: ApiKeyRow): KeyContext {
+    const existing = this.cache.get(keyRow.id);
+    if (existing) {
+      // LRU bump: re-insert to move to the end of iteration order.
+      this.cache.delete(keyRow.id);
+      this.cache.set(keyRow.id, existing);
+      return existing;
+    }
+
+    const privHex = unseal(
+      { nonce: keyRow.enc_priv_nonce, ct: keyRow.enc_priv_ct, tag: keyRow.enc_priv_tag },
+      this.deps.masterKeyHex,
+    );
+    const walletKey = deriveWalletKey(privHex, this.deps.networkId);
+    const sdk = new Marketplace({
+      chain: this.deps.chain,
+      indexerUrl: this.deps.indexerUrl,
+      walletKey,
+      networkParams: { networkId: this.deps.networkId },
+      historyStore: new MemoryTaskHistoryStore(),
+    });
+    const ctx: KeyContext = { sdk, mutex: new Mutex(), walletKey };
+    this.cache.set(keyRow.id, ctx);
+    this.evictIfNeeded();
+    return ctx;
+  }
+
+  private evictIfNeeded(): void {
+    while (this.cache.size > this.deps.max) {
+      const oldest = this.cache.keys().next().value as string | undefined;
+      if (oldest === undefined) break;
+      this.cache.delete(oldest);
+    }
+  }
+}

gateway/src/server.ts

@@ -0,0 +1,94 @@
+/**
+ * gateway/src/server.ts — Express app wiring.
+ *
+ * Public:   GET /healthz, GET /, POST /signup (IP rate-limited).
+ * Bearer:   GET /account, POST /account/withdraw,
+ *           POST /openai/v1/chat/completions, GET /openai/v1/models,
+ *           POST /openai/v1/chat/sessions[/:id/messages|/close].
+ */
+
+import express, { type Express, type NextFunction, type Request, type Response } from "express";
+import type { GatewayDeps } from "./deps.js";
+import { makeApiKeyAuth } from "./middleware/apiKeyAuth.js";
+import { ipRateLimit, keyRateLimit, demoIpRateLimit } from "./middleware/rateLimit.js";
+import { sendError } from "./middleware/http.js";
+import { notFound } from "./openai/errors.js";
+import { makeChatCompletionsHandler } from "./openai/chatCompletions.js";
+import { makeModelsHandler } from "./openai/models.js";
+import {
+  makeOpenSessionHandler,
+  makeSessionMessageHandler,
+  makeCloseSessionHandler,
+} from "./openai/sessions.js";
+import { makeSignupHandler, makeAccountHandler, makeWithdrawHandler } from "./account/routes.js";
+import { INDEX_HTML } from "./ui/page.js";
+
+/**
+ * CORS for browser clients on an allowlisted Origin (e.g. the marketplace
+ * frontend's "Generate API key" page, served from a different host than the
+ * gateway). Only echoes Access-Control-* headers when the request's Origin is
+ * in the configured allowlist; an empty allowlist disables CORS entirely.
+ * No credentials are allowed — the signup call is a plain bearer-less POST, so
+ * cookies never ride along cross-origin. Preflight OPTIONS is answered 204.
+ */
+function corsMiddleware(allowOrigins: string[]) {
+  const allow = new Set(allowOrigins);
+  return (req: Request, res: Response, next: NextFunction): void => {
+    const origin = req.headers.origin;
+    if (typeof origin === "string" && allow.has(origin)) {
+      res.setHeader("Access-Control-Allow-Origin", origin);
+      res.setHeader("Vary", "Origin");
+      res.setHeader("Access-Control-Allow-Methods", "GET, POST, OPTIONS");
+      res.setHeader("Access-Control-Allow-Headers", "Content-Type, Authorization");
+      res.setHeader("Access-Control-Max-Age", "600");
+    }
+    if (req.method === "OPTIONS") {
+      res.status(204).end();
+      return;
+    }
+    next();
+  };
+}
+
+export function createApp(deps: GatewayDeps): Express {
+  const app = express();
+  // Behind traefik/Cloudflare — trust the proxy chain so req.ip is the client.
+  app.set("trust proxy", true);
+  // CORS before body-parsing so preflight OPTIONS short-circuits cheaply.
+  app.use(corsMiddleware(deps.config.corsOrigins));
+  app.use(express.json({ limit: "1mb" }));
+
+  app.get("/healthz", (_req: Request, res: Response) => {
+    res.json({ ok: true });
+  });
+
+  app.get("/", (_req: Request, res: Response) => {
+    res.status(200).type("html").send(INDEX_HTML);
+  });
+
+  // Public signup, rate-limited per IP.
+  app.post("/signup", ipRateLimit(deps.config.signupRate), makeSignupHandler(deps));
+
+  // Bearer-gated routes: auth → per-key rate limit (skips demo keys) →
+  // per-IP demo limit (demo keys only) → handler.
+  const auth = makeApiKeyAuth(deps.store);
+  const krl = keyRateLimit(deps.config.keyRate);
+  const dirl = demoIpRateLimit(deps.config.demoIpRate);
+  const gated = [auth, krl, dirl] as const;
+
+  app.get("/account", auth, makeAccountHandler(deps));
+  app.post("/account/withdraw", auth, makeWithdrawHandler(deps));
+
+  app.post("/openai/v1/chat/completions", ...gated, makeChatCompletionsHandler(deps));
+  app.get("/openai/v1/models", auth, makeModelsHandler(deps));
+  app.post("/openai/v1/chat/sessions", ...gated, makeOpenSessionHandler(deps));
+  app.post("/openai/v1/chat/sessions/:id/messages", ...gated, makeSessionMessageHandler(deps));
+  app.post("/openai/v1/chat/sessions/:id/close", ...gated, makeCloseSessionHandler(deps));
+
+  // OpenAI-shaped 404 for anything else.
+  app.use((_req: Request, res: Response) => {
+    sendError(res, notFound("not_found", "unknown route"));
+  });
+
+  return app;
+}

gateway/src/sweeper.ts

@@ -0,0 +1,224 @@
+/**
+ * gateway/src/sweeper.ts — state-aware custody safety net.
+ *
+ * Per key, classifies on-chain escrows and recovers stranded funds:
+ *   Open|Claimed past the deliver_by deadline → Reclaim (returns funds + bond).
+ *   Submitted (verified, in accept-window)    → retry Accept (settle + refund).
+ *   Submitted past the accept-window          → leave for supplier Release (log).
+ *
+ * reclaim only works on Open/Claimed; Accept only on Submitted — so we branch by
+ * state and never blind-reclaim a Submitted escrow. The on-chain validator is
+ * the source of truth for deadlines, so premature/late attempts simply fail and
+ * are caught here; the age thresholds just avoid racing in-flight requests.
+ *
+ * Chat sessions get special handling:
+ *   - Their deliver_by is ~30 min (vs ~10 min one-shot), so rows belonging to
+ *     an OPEN session use CHAT_RECLAIM_AFTER_MS — otherwise every open session
+ *     older than 11 min would trigger a doomed Reclaim attempt per sweep while
+ *     holding the key's mutex.
+ *   - When a session's escrow reaches a terminal state (Accepted here, spent
+ *     elsewhere, or Reclaimed), the session row is closed, its in-memory state
+ *     dropped, and a usage row recorded — abandoned demo sessions (nobody calls
+ *     /close) settle and get billed through this path.
+ *
+ * Escrow↔session lineage: the indexer keeps one row per utxo_ref per state
+ * (terminal spends update nothing), and the validator preserves posted_at
+ * across states — so a session's lineage is "rows sharing the posted_at of the
+ * session's original Open ref row".
+ *
+ * Because terminal spends never update indexer rows, every settled escrow
+ * would be retried (one doomed chain query each) on every sweep forever. The
+ * in-process `settledRefs` memory skips refs this process has already settled
+ * or found spent; a restart just causes one harmless retry burst.
+ *
+ * Ticket mode (config.chatSettleMode === "ticket"): session escrows are never
+ * Claimed — they sit Open until reclaimed here after deliver_by. Reclaiming
+ * an Open ticket does NOT close a still-open session row: nothing re-checks
+ * the escrow after /v1/chat/start, so the conversation (and its affinity
+ * mirror) lives on, bounded only by the idle janitor.
+ */
+
+import { randomUUID } from "crypto";
+import type { GatewayDeps } from "./deps.js";
+import type { SessionRow } from "./db/store.js";
+import { fetchEscrows, acceptAndConfirm, reclaimAndConfirm, type EscrowRow } from "./onchain/settle.js";
+import { parseRef } from "./routing/selectSupplier.js";
+import { dropSessionState } from "./openai/transcripts.js";
+import { dropDemoSession, sweepIdleDemoSessions } from "./openai/demoChat.js";
+import { CAPABILITY as CHAT_CAPABILITY } from "./openai/sessions.js";
+
+// Don't touch escrows newer than this — an in-flight request is settling them.
+const MIN_AGE_MS = 90_000;
+// Reclaim Open/Claimed escrows older than this (past deliver_by ~10m + buffer).
+const RECLAIM_AFTER_MS = 11 * 60 * 1000;
+// Chat-session escrows: deliver_by ≈ posted_at + 30 min, so wait longer.
+const CHAT_RECLAIM_AFTER_MS = 35 * 60 * 1000;
+// Reclaim only fires once the validator allows it (validity lower bound >=
+// deliver_by); attempting earlier is a guaranteed-doomed tx build.
+const DELIVER_BY_BUFFER_MS = 60_000;
+
+/** Refs this process already settled (Accepted/Reclaimed) or found spent.
+ * The indexer never updates terminal rows, so without this every historical
+ * escrow is retried each sweep. Bounded FIFO; restart = one retry burst. */
+const settledRefs = new Set<string>();
+const SETTLED_REFS_MAX = 5_000;
+
+function markSettled(ref: string): void {
+  settledRefs.add(ref);
+  if (settledRefs.size > SETTLED_REFS_MAX) {
+    const first = settledRefs.values().next().value;
+    if (first !== undefined) settledRefs.delete(first);
+  }
+}
+
+function log(msg: string): void {
+  // eslint-disable-next-line no-console
+  console.log(`[gateway:sweeper] ${msg}`);
+}
+
+function closeSessionRow(
+  deps: GatewayDeps,
+  session: SessionRow,
+  outcome: { status: "completed" | "reclaimed"; costLovelace: string | null },
+): void {
+  // Re-read: an in-flight close (route handler or demo executor) may have won.
+  const current = deps.store.getSession(session.id);
+  if (!current || current.state !== "open") return;
+  deps.store.setSessionState(session.id, "closed", Date.now());
+  dropSessionState(session.id);
+  dropDemoSession(session.id);
+  deps.store.insertUsage({
+    id: randomUUID(),
+    key_id: session.key_id,
+    created_at: Date.now(),
+    kind: "chat_session",
+    model: session.model,
+    capability_id: CHAT_CAPABILITY,
+    supplier_pkh: session.supplier_pkh,
+    escrow_ref: session.escrow_ref,
+    cost_lovelace: outcome.costLovelace,
+    prompt_tokens: 0,
+    completion_tokens: 0,
+    status: outcome.status,
+    failure_reason: null,
+  });
+  log(`closed abandoned session ${session.id} (${outcome.status})`);
+}
+
+/** Chain-settle functions, injectable for tests. */
+export interface SweepSettleFns {
+  accept: typeof acceptAndConfirm;
+  reclaim: typeof reclaimAndConfirm;
+}
+
+export async function runSweepOnce(
+  deps: GatewayDeps,
+  settle: SweepSettleFns = { accept: acceptAndConfirm, reclaim: reclaimAndConfirm },
+): Promise<void> {
+  // Idle demo sessions first: closing them makes the supplier Submit, so this
+  // sweep (or the next) can Accept the escrow right after.
+  await sweepIdleDemoSessions(deps).catch((err) =>
+    log(`demo idle janitor: ${err instanceof Error ? err.message : String(err)}`),
+  );
+
+  const now = Date.now();
+  for (const keyRow of deps.store.listKeys()) {
+    let rows: EscrowRow[];
+    try {
+      rows = await fetchEscrows(deps.config.indexerUrl, keyRow.wallet_pkh, deps.fetchFn);
+    } catch (err) {
+      log(`indexer error for ${keyRow.key_prefix}: ${err instanceof Error ? err.message : String(err)}`);
+      continue;
+    }
+
+    // Lineage-match open sessions: the session stores its ORIGINAL Open ref;
+    // rows sharing that row's posted_at are the same escrow in later states.
+    const sessionByPostedAt = new Map<number, SessionRow>();
+    for (const session of deps.store.listOpenSessionsByKey(keyRow.id)) {
+      const origin = rows.find((r) => r.utxo_ref === session.escrow_ref);
+      if (origin) sessionByPostedAt.set(origin.posted_at, session);
+    }
+
+    const ctx = deps.registry.getContext(keyRow);
+    for (const row of rows) {
+      const ref = parseRef(row.utxo_ref);
+      if (!ref) continue;
+      if (settledRefs.has(row.utxo_ref)) continue;
+      const ageMs = now - (row.posted_at ?? 0);
+      if (ageMs < MIN_AGE_MS) continue;
+      const chatSession = sessionByPostedAt.get(row.posted_at);
+
+      try {
+        if (row.state === "Submitted") {
+          try {
+            await ctx.mutex.run(() => settle.accept(deps.chain, ctx.walletKey, ref));
+            log(`accepted stranded Submitted escrow ${row.utxo_ref}`);
+            markSettled(row.utxo_ref);
+            if (chatSession) {
+              closeSessionRow(deps, chatSession, { status: "completed", costLovelace: chatSession.price_lovelace });
+            }
+          } catch (err) {
+            // Accept fails routinely when the UTxO is already spent (settled
+            // by an in-flight request, an earlier sweep, or supplier Release).
+            // For session lineages, confirm the spend on-chain before closing
+            // the row — an Accept that failed for another reason (timeout)
+            // must leave the session open for the next sweep.
+            if ((await deps.chain.queryUtxo(ref)) === null) {
+              markSettled(row.utxo_ref);
+              if (chatSession) {
+                closeSessionRow(deps, chatSession, { status: "completed", costLovelace: chatSession.price_lovelace });
+              }
+            } else if (!chatSession) {
+              // Preserve the historical quiet-skip for one-shot escrows.
+              void err;
+            }
+          }
+        } else if (row.state === "Open" || row.state === "Claimed") {
+          const reclaimAfterMs = chatSession ? CHAT_RECLAIM_AFTER_MS : RECLAIM_AFTER_MS;
+          // The validator only allows Reclaim at/after deliver_by — skip
+          // attempts that cannot succeed yet (early-closed ticket sessions).
+          const pastDeliverBy =
+            typeof row.deliver_by === "number" ? now > row.deliver_by + DELIVER_BY_BUFFER_MS : true;
+          if (ageMs > reclaimAfterMs && pastDeliverBy) {
+            await ctx.mutex.run(() => settle.reclaim(deps.chain, ctx.walletKey, ref));
+            log(`reclaimed stranded ${row.state} escrow ${row.utxo_ref}`);
+            markSettled(row.utxo_ref);
+            if (chatSession) {
+              const ticketOpen = deps.config.chatSettleMode === "ticket" && row.state === "Open";
+              if (ticketOpen) {
+                // Ticket escrow reclaimed out from under a LIVE session —
+                // by design. Keep the session row + mirror; only the idle
+                // janitor / close paths end ticket sessions.
+                log(`ticket mode: escrow reclaimed, session ${chatSession.id} stays open`);
+              } else {
+                // Funds returned — the session never settled; record no cost.
+                closeSessionRow(deps, chatSession, { status: "reclaimed", costLovelace: null });
+              }
+            }
+          }
+        }
+      } catch {
+        // Expected when the validator rejects (wrong window/state) or the UTxO
+        // was already spent by an in-flight request; skip quietly.
+      }
+    }
+  }
+}
+
+/** Start the periodic sweeper. Returns a stop() function. */
+export function startSweeper(deps: GatewayDeps): () => void {
+  let running = false;
+  const tick = async (): Promise<void> => {
+    if (running) return;
+    running = true;
+    try {
+      await runSweepOnce(deps);
+    } catch (err) {
+      log(`sweep failed: ${err instanceof Error ? err.message : String(err)}`);
+    } finally {
+      running = false;
+    }
+  };
+  const handle = setInterval(() => void tick(), deps.config.sweeperIntervalMs);
+  return () => clearInterval(handle);
+}

gateway/src/ui/page.ts

@@ -0,0 +1,81 @@
+/**
+ * gateway/src/ui/page.ts — self-serve web UI, inlined as a string so it ships
+ * in dist/ (tsc does not copy .html). Plain HTML + fetch, no build step.
+ */
+
+export const INDEX_HTML = `<!doctype html>
+<html lang="en">
+<head>
+<meta charset="utf-8" />
+<meta name="viewport" content="width=device-width, initial-scale=1" />
+<title>Vector Marketplace - OpenAI Gateway</title>
+<style>
+  body { font-family: system-ui, sans-serif; max-width: 760px; margin: 2rem auto; padding: 0 1rem; line-height: 1.5; }
+  h1 { font-size: 1.5rem; } h2 { font-size: 1.1rem; margin-top: 2rem; }
+  code, pre { background: #f4f4f5; border-radius: 4px; padding: .15rem .35rem; }
+  pre { padding: .75rem; overflow-x: auto; }
+  input, button { font-size: 1rem; padding: .45rem .6rem; border-radius: 6px; border: 1px solid #ccc; }
+  button { background: #111; color: #fff; cursor: pointer; border: none; }
+  .row { display: flex; gap: .5rem; flex-wrap: wrap; align-items: center; margin: .5rem 0; }
+  .key { background: #fffbe6; border: 1px solid #f5d90a; padding: .75rem; border-radius: 6px; word-break: break-all; }
+  .muted { color: #666; font-size: .9rem; }
+</style>
+</head>
+<body>
+<h1>Vector Marketplace - OpenAI-compatible Gateway</h1>
+<p class="muted">Point any OpenAI SDK at <code id="base"></code> using your API key as the bearer token.</p>
+
+<h2>1. Create an API key</h2>
+<div class="row">
+  <input id="label" placeholder="label (optional)" />
+  <button onclick="signup()">Create key</button>
+</div>
+<div id="signupOut"></div>
+
+<h2>2. Fund your wallet</h2>
+<p class="muted">Send AP3X to your deposit address (you need price + bonds + ~5 AP3X collateral + fees).</p>
+
+<h2>3. Account</h2>
+<div class="row">
+  <input id="apiKey" placeholder="vk_..." style="flex:1; min-width: 320px" />
+  <button onclick="account()">Check account</button>
+</div>
+<div id="acctOut"></div>
+
+<h2>4. Withdraw</h2>
+<div class="row">
+  <input id="toAddr" placeholder="addr... (destination)" style="flex:1; min-width: 320px" />
+  <input id="amt" placeholder="amount lovelace (blank = all)" />
+  <button onclick="withdraw()">Withdraw</button>
+</div>
+<div id="wOut"></div>
+
+<script>
+document.getElementById('base').textContent = location.origin + '/openai/v1';
+function pre(id, obj){ document.getElementById(id).innerHTML = '<pre>'+JSON.stringify(obj,null,2)+'</pre>'; }
+async function signup(){
+  const label = document.getElementById('label').value;
+  const r = await fetch('/signup', {method:'POST', headers:{'content-type':'application/json'}, body: JSON.stringify({label})});
+  const j = await r.json();
+  if (j.api_key) {
+    document.getElementById('signupOut').innerHTML =
+      '<div class="key"><b>API key (shown once):</b><br>'+j.api_key+'<br><br><b>Deposit address:</b><br>'+j.deposit_address+'</div>';
+    document.getElementById('apiKey').value = j.api_key;
+    document.getElementById('toAddr').value = '';
+  } else pre('signupOut', j);
+}
+function authHeaders(){ return {'authorization':'Bearer '+document.getElementById('apiKey').value, 'content-type':'application/json'}; }
+async function account(){
+  const r = await fetch('/account', {headers: authHeaders()});
+  pre('acctOut', await r.json());
+}
+async function withdraw(){
+  const to_address = document.getElementById('toAddr').value;
+  const amt = document.getElementById('amt').value.trim();
+  const body = amt ? {to_address, amount_lovelace: amt} : {to_address};
+  const r = await fetch('/account/withdraw', {method:'POST', headers: authHeaders(), body: JSON.stringify(body)});
+  pre('wOut', await r.json());
+}
+</script>
+</body>
+</html>`;

gateway/src/wallet.ts

@@ -0,0 +1,60 @@
+/**
+ * gateway/src/wallet.ts — per-user wallet key derivation.
+ *
+ * Copied from buyer/src/index.ts:24-64 (deriveWalletKey + ed25519 sha512 hook)
+ * so the gateway does not have to import the buyer entrypoint (which boots an
+ * Express server). genPrivKeyHex mints a fresh custodial wallet at signup.
+ */
+
+import { createHash, randomBytes } from "crypto";
+import * as ed from "@noble/ed25519";
+import { blake2b } from "@noble/hashes/blake2b";
+import { bech32 } from "bech32";
+import type { WalletKey } from "@marketplace/shared/tx";
+
+// Wire ed25519 sha512 hook (idempotent — same as buyer/src/index.ts + receipt/sign.ts).
+ed.etc.sha512Sync = (...messages: Uint8Array[]): Uint8Array => {
+  const h = createHash("sha512");
+  for (const m of messages) h.update(m);
+  return new Uint8Array(h.digest());
+};
+
+function hexToBytes(hex: string): Uint8Array {
+  const bytes = new Uint8Array(hex.length / 2);
+  for (let i = 0; i < hex.length; i += 2) {
+    bytes[i / 2] = parseInt(hex.substring(i, i + 2), 16);
+  }
+  return bytes;
+}
+
+function bytesToHex(b: Uint8Array): string {
+  let out = "";
+  for (let i = 0; i < b.length; i++) out += b[i].toString(16).padStart(2, "0");
+  return out;
+}
+
+/** Mint a fresh 32-byte Ed25519 private key as 64-char hex. */
+export function genPrivKeyHex(): string {
+  return bytesToHex(new Uint8Array(randomBytes(32)));
+}
+
+export function deriveWalletKey(privHex: string, networkId: 0 | 1): WalletKey {
+  const priv = hexToBytes(privHex);
+  const pub = ed.getPublicKey(priv);
+  const pubHex = bytesToHex(pub);
+  const pkh = blake2b(pub, { dkLen: 28 });
+  const pkhHex = bytesToHex(pkh);
+  const header = networkId === 0 ? 0x60 : 0x61;
+  const payload = new Uint8Array(29);
+  payload[0] = header;
+  payload.set(pkh, 1);
+  const words = bech32.toWords(payload);
+  const hrp = networkId === 0 ? "addr_test" : "addr";
+  const addr = bech32.encode(hrp, words, 1023);
+  return {
+    pubKeyHash: pkhHex,
+    pubKeyHex: pubHex,
+    privateKeyHex: privHex,
+    address: addr,
+  };
+}

gateway/src/walletHealth.ts

@@ -0,0 +1,49 @@
+/**
+ * gateway/src/walletHealth.ts — keep each custodial wallet usable.
+ *
+ * After every settled request (and on a periodic tick) we re-shape the wallet to
+ * {≥5 AP3X collateral UTxO, working UTxO} via the shared consolidate builder, so
+ * the NEXT request's Accept/Reclaim script-spend always finds a pure-AP3X
+ * collateral candidate. No-op when the wallet is already healthy.
+ */
+
+import type { LiveOgmiosProvider } from "@marketplace/shared/chain";
+import type { WalletKey } from "@marketplace/shared/tx";
+import { runConsolidateWallet, DEFAULT_COLLATERAL_LOVELACE } from "@marketplace/shared/tx/server";
+import type { GatewayDeps } from "./deps.js";
+
+export async function ensureWalletHealthy(
+  chain: LiveOgmiosProvider,
+  walletKey: WalletKey,
+): Promise<void> {
+  await runConsolidateWallet({
+    chain,
+    walletKey,
+    collateralLovelace: DEFAULT_COLLATERAL_LOVELACE,
+    log: () => {
+      /* quiet; callers log failures */
+    },
+  });
+}
+
+/** Periodically re-shape every wallet so a collateral UTxO is always available.
+ * Serialized per key via the registry mutex; no-op for already-healthy wallets. */
+export function startWalletHealthTicker(deps: GatewayDeps): () => void {
+  let running = false;
+  const tick = async (): Promise<void> => {
+    if (running) return;
+    running = true;
+    try {
+      for (const keyRow of deps.store.listKeys()) {
+        const ctx = deps.registry.getContext(keyRow);
+        await ctx.mutex.run(() => ensureWalletHealthy(deps.chain, ctx.walletKey)).catch(() => {
+          /* skip wallets that can't consolidate (e.g. drained) */
+        });
+      }
+    } finally {
+      running = false;
+    }
+  };
+  const handle = setInterval(() => void tick(), deps.config.walletHealthIntervalMs);
+  return () => clearInterval(handle);
+}

gateway/test/affinity.test.ts

@@ -0,0 +1,143 @@
+/**
+ * affinity.test.ts — transcript-prefix session matching rules.
+ */
+
+import { describe, it, expect } from "vitest";
+import {
+  matchSessionPrefix,
+  normalizeAssistantContent,
+  trimToRespondable,
+  type AffinityCandidate,
+} from "../src/openai/affinity.js";
+import type { ChatMessage } from "@marketplace/shared/tx";
+
+const u = (content: string): ChatMessage => ({ role: "user", content });
+const a = (content: string): ChatMessage => ({ role: "assistant", content });
+const TOOL_CALL = { id: "call_1", type: "function" as const, function: { name: "get_time", arguments: "{}" } };
+
+function cand(sessionId: string, mirror: ChatMessage[], lastUsedAt = 0, model = "m"): AffinityCandidate {
+  return { sessionId, model, mirror, lastUsedAt };
+}
+
+describe("matchSessionPrefix", () => {
+  it("matches an exact prefix and returns the delta", () => {
+    const got = matchSessionPrefix([cand("s1", [u("hi"), a("hello")])], [u("hi"), a("hello"), u("more")], "m");
+    expect(got).toEqual({ sessionId: "s1", delta: [u("more")] });
+  });
+
+  it("accepts a multi-message tool delta ending with a tool result", () => {
+    const mirror = [u("hi"), { role: "assistant" as const, content: "", tool_calls: [TOOL_CALL] }];
+    const incoming = [...mirror, { role: "tool" as const, content: "3pm", tool_call_id: "call_1" }];
+    const got = matchSessionPrefix([cand("s1", mirror)], incoming, "m");
+    expect(got?.sessionId).toBe("s1");
+    expect(got?.delta).toHaveLength(1);
+    expect(got?.delta[0].role).toBe("tool");
+  });
+
+  it("rejects deltas that end with a non-respondable role", () => {
+    const got = matchSessionPrefix([cand("s1", [u("hi")])], [u("hi"), a("stray assistant")], "m");
+    expect(got).toBeNull();
+  });
+
+  it("never matches when incoming is not longer than the mirror (retry of answered request)", () => {
+    const mirror = [u("hi"), a("hello")];
+    expect(matchSessionPrefix([cand("s1", mirror)], mirror, "m")).toBeNull();
+    expect(matchSessionPrefix([cand("s1", mirror)], [u("hi")], "m")).toBeNull();
+  });
+
+  it("rejects diverged histories (prefix mismatch)", () => {
+    const got = matchSessionPrefix([cand("s1", [u("hi"), a("hello")])], [u("hi"), a("DIFFERENT"), u("more")], "m");
+    expect(got).toBeNull();
+  });
+
+  it("requires the model to match", () => {
+    expect(matchSessionPrefix([cand("s1", [u("hi")], 0, "other")], [u("hi"), u("more")], "m")).toBeNull();
+  });
+
+  it("prefers the longest mirror, then most recently used", () => {
+    const incoming = [u("hi"), a("hello"), u("more")];
+    const longest = matchSessionPrefix(
+      [cand("short", [u("hi")], 99), cand("long", [u("hi"), a("hello")], 0)],
+      incoming,
+      "m",
+    );
+    expect(longest?.sessionId).toBe("long");
+
+    const tie = matchSessionPrefix(
+      [cand("old", [u("hi"), a("hello")], 1), cand("recent", [u("hi"), a("hello")], 2)],
+      incoming,
+      "m",
+    );
+    expect(tie?.sessionId).toBe("recent");
+  });
+
+  it("matches an empty mirror (fresh session) against any respondable history", () => {
+    const incoming = [{ role: "system" as const, content: "be nice" }, u("hi")];
+    const got = matchSessionPrefix([cand("fresh", [])], incoming, "m");
+    expect(got).toEqual({ sessionId: "fresh", delta: incoming });
+  });
+
+  it("treats content null-normalization as equivalent (tool-call assistant echo)", () => {
+    const mirror = [u("hi"), { role: "assistant" as const, content: "", tool_calls: [TOOL_CALL] }];
+    // Client echoes the assistant message back with content:"" (normalized from null upstream).
+    const incoming = [u("hi"), { role: "assistant" as const, content: "", tool_calls: [{ ...TOOL_CALL }] }, { role: "tool" as const, content: "x", tool_call_id: "call_1" }];
+    expect(matchSessionPrefix([cand("s1", mirror)], incoming, "m")?.sessionId).toBe("s1");
+  });
+
+  it("matches leniently when the client reshapes the assistant echo (think-strip + whitespace)", () => {
+    const mirror = [u("hi"), a("<think>plan it</think>Hello  there\n")];
+    const got = matchSessionPrefix([cand("s1", mirror)], [u("hi"), a("Hello there"), u("more")], "m");
+    expect(got).toEqual({ sessionId: "s1", delta: [u("more")] });
+  });
+
+  it("stays strict on user/tool divergence even with lenient assistant matching", () => {
+    const mirror = [u("hi "), a("Hello")];
+    // User content differs by whitespace — client-authored roles must be byte-exact.
+    expect(matchSessionPrefix([cand("s1", mirror)], [u("hi"), a("Hello"), u("more")], "m")).toBeNull();
+  });
+
+  it("rejects assistant tool_calls divergence under lenient matching", () => {
+    const mirror = [u("hi"), { role: "assistant" as const, content: "x", tool_calls: [TOOL_CALL] }];
+    const changed = { ...TOOL_CALL, function: { name: "get_time", arguments: '{"tz":"utc"}' } };
+    const incoming = [u("hi"), { role: "assistant" as const, content: "x ", tool_calls: [changed] }, { role: "tool" as const, content: "t", tool_call_id: "call_1" }];
+    expect(matchSessionPrefix([cand("s1", mirror)], incoming, "m")).toBeNull();
+  });
+
+  it("prefers a strict match over a lenient one regardless of recency", () => {
+    const incoming = [u("hi"), a("Hello"), u("more")];
+    const got = matchSessionPrefix(
+      [
+        cand("lenient", [u("hi"), a("Hello   ")], 99),
+        cand("strict", [u("hi"), a("Hello")], 1),
+      ],
+      incoming,
+      "m",
+    );
+    expect(got?.sessionId).toBe("strict");
+  });
+});
+
+describe("normalizeAssistantContent", () => {
+  it("strips think blocks, collapses whitespace and trims", () => {
+    expect(normalizeAssistantContent("<think>a\nb</think> Hi\n\nthere  friend ")).toBe("Hi there friend");
+    expect(normalizeAssistantContent("<THINK>x</THINK>ok")).toBe("ok");
+    expect(normalizeAssistantContent("plain")).toBe("plain");
+  });
+});
+
+describe("trimToRespondable", () => {
+  it("drops trailing assistant/system messages", () => {
+    expect(trimToRespondable([u("hi"), a("partial")])).toEqual([u("hi")]);
+    expect(trimToRespondable([u("hi"), a("x"), { role: "system" as const, content: "nudge" }])).toEqual([u("hi")]);
+  });
+
+  it("returns empty when nothing respondable remains", () => {
+    expect(trimToRespondable([a("hello")])).toEqual([]);
+    expect(trimToRespondable([])).toEqual([]);
+  });
+
+  it("keeps already-respondable histories unchanged", () => {
+    const msgs = [u("hi"), a("x"), u("more")];
+    expect(trimToRespondable(msgs)).toEqual(msgs);
+  });
+});

gateway/test/http.test.ts

@@ -0,0 +1,570 @@
+import { describe, it, expect, vi } from "vitest";
+import { tmpdir } from "os";
+import { join } from "path";
+import { randomBytes, randomUUID } from "crypto";
+import request from "supertest";
+import { createApp } from "../src/server.js";
+import { sweepIdleDemoSessions } from "../src/openai/demoChat.js";
+import { GatewayStore } from "../src/db/store.js";
+import { SdkRegistry } from "../src/sdk/registry.js";
+import { genPrivKeyHex, deriveWalletKey } from "../src/wallet.js";
+import { seal } from "../src/crypto/seal.js";
+import { hashApiKey } from "../src/middleware/apiKeyAuth.js";
+import type { GatewayConfig } from "../src/config.js";
+import type { GatewayDeps } from "../src/deps.js";
+
+const MASTER = "ab".repeat(32);
+
+const SUPPLIERS = [
+  { utxo_ref: "aa".repeat(32) + "#0", supplier_pkh: "s1", capability_id: "llm.text.generate.v1", model: "qwen", max_output_tokens: 256, price_lovelace: "1000000", supplier_bond_lovelace: "1000000", buyer_bond_lovelace: "1000000", endpoint_url: "http://sup", advert_status: "Active", status: "free" },
+  { utxo_ref: "bb".repeat(32) + "#0", supplier_pkh: "s2", capability_id: "llm.chat.v1", model: "kimi", max_output_tokens: 256, price_lovelace: "1000000", supplier_bond_lovelace: "1000000", buyer_bond_lovelace: "1000000", endpoint_url: "http://sup", advert_status: "Active", status: "free" },
+];
+
+function makeDeps(
+  fetchFn?: typeof globalThis.fetch,
+  overrides?: {
+    demoIpRate?: { max: number; windowMs: number };
+    chain?: GatewayDeps["chain"];
+    chatSettleMode?: "full" | "ticket";
+  },
+): GatewayDeps {
+  const dbDir = join(tmpdir(), `gw-test-${randomUUID()}`);
+  const store = new GatewayStore(dbDir);
+  const config: GatewayConfig = {
+    masterKeyHex: MASTER,
+    indexerUrl: "http://ix",
+    ogmiosUrl: "http://og",
+    networkId: 0,
+    liveChain: true,
+    port: 0,
+    dbDir,
+    signupRate: { max: 1000, windowMs: 60_000 },
+    keyRate: { max: 1000, windowMs: 60_000 },
+    demoIpRate: overrides?.demoIpRate ?? { max: 1000, windowMs: 60_000 },
+    sweeperIntervalMs: 60_000,
+    demoSessionIdleMs: 180_000,
+    chatSettleMode: overrides?.chatSettleMode ?? "full",
+    walletHealthIntervalMs: 600_000,
+    sdkRegistryMax: 100,
+    corsOrigins: [],
+  };
+  const chain = overrides?.chain ?? ({ queryUtxosByAddress: async () => [] } as unknown as GatewayDeps["chain"]);
+  const registry = new SdkRegistry({
+    chain,
+    indexerUrl: config.indexerUrl,
+    networkId: config.networkId,
+    masterKeyHex: config.masterKeyHex,
+    max: config.sdkRegistryMax,
+  });
+  const defaultFetch = (async () => new Response("[]", { status: 200 })) as unknown as typeof globalThis.fetch;
+  return { config, store, chain, registry, fetchFn: fetchFn ?? defaultFetch };
+}
+
+describe("gateway HTTP", () => {
+  it("GET /healthz", async () => {
+    const res = await request(createApp(makeDeps())).get("/healthz");
+    expect(res.status).toBe(200);
+    expect(res.body).toEqual({ ok: true });
+  });
+
+  it("GET / serves the UI", async () => {
+    const res = await request(createApp(makeDeps())).get("/");
+    expect(res.status).toBe(200);
+    expect(res.text).toContain("OpenAI-compatible Gateway");
+  });
+
+  it("rejects unauthenticated chat completions with OpenAI error shape", async () => {
+    const res = await request(createApp(makeDeps()))
+      .post("/openai/v1/chat/completions")
+      .send({ model: "qwen", messages: [{ role: "user", content: "hi" }] });
+    expect(res.status).toBe(401);
+    expect(res.body.error.type).toBe("authentication_error");
+    expect(res.body.error.code).toBe("invalid_api_key");
+  });
+
+  it("signup → account roundtrip", async () => {
+    const app = createApp(makeDeps());
+    const signup = await request(app).post("/signup").send({ label: "test" });
+    expect(signup.status).toBe(201);
+    expect(signup.body.api_key).toMatch(/^vk_test_[0-9a-f]{48}$/);
+    expect(signup.body.deposit_address).toMatch(/^addr_test1/);
+
+    const key = signup.body.api_key as string;
+    const acct = await request(app).get("/account").set("authorization", `Bearer ${key}`);
+    expect(acct.status).toBe(200);
+    expect(acct.body.balance.available_lovelace).toBe("0");
+    expect(acct.body.collateral_ok).toBe(false);
+    expect(acct.body.spend.request_count).toBe(0);
+  });
+
+  it("GET /openai/v1/models lists distinct models", async () => {
+    const fetchFn = (async (url: string) =>
+      new Response(JSON.stringify(String(url).includes("/suppliers") ? SUPPLIERS : []), { status: 200 })) as unknown as typeof globalThis.fetch;
+    const app = createApp(makeDeps(fetchFn));
+    const signup = await request(app).post("/signup").send({});
+    const key = signup.body.api_key as string;
+    const res = await request(app).get("/openai/v1/models").set("authorization", `Bearer ${key}`);
+    expect(res.status).toBe(200);
+    expect(res.body.object).toBe("list");
+    expect(res.body.data.map((m: { id: string }) => m.id)).toContain("qwen");
+  });
+
+  it("rejects tools/functions with 400 before any chain work", async () => {
+    const app = createApp(makeDeps());
+    const signup = await request(app).post("/signup").send({});
+    const key = signup.body.api_key as string;
+    const res = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${key}`)
+      .send({ model: "qwen", messages: [{ role: "user", content: "hi" }], tools: [{ type: "function" }] });
+    expect(res.status).toBe(400);
+    expect(res.body.error.code).toBe("unsupported_parameter");
+  });
+});
+
+// ─── Shared demo key (session-backed completions) ───────────────────────────
+
+const TOOLS = [{ type: "function", function: { name: "get_time", parameters: {} } }];
+const TOOL_CALL = { id: "call_1", type: "function", function: { name: "get_time", arguments: "{}" } };
+
+/** A funded wallet: covers price+bonds+collateral+fee and has pure-ADA ≥ 5. */
+const fundedChain = {
+  queryUtxosByAddress: async () => [
+    { ref: { txHash: "ff".repeat(32), index: 0 }, address: "a", lovelace: 20_000_000n, assets: {}, datumHex: null, scriptRef: null },
+  ],
+} as unknown as GatewayDeps["chain"];
+
+function supplierSse(frames: unknown[]): Response {
+  const body = frames.map((f) => `data: ${JSON.stringify(f)}\n\n`).join("");
+  return new Response(body, { status: 200, headers: { "content-type": "text/event-stream" } });
+}
+
+function doneFrame(message: Record<string, unknown>, finishReason: string, usage = { prompt_tokens: 3, completion_tokens: 2 }) {
+  return { type: "done", message, finish_reason: finishReason, usage };
+}
+
+/** fetchFn serving the indexer supplier list and scripted /v1/chat/message
+ * responses. Pass `suppliers` to serve a mutable list (eviction tests flip
+ * status mid-test); /v1/chat/end calls are recorded and 200-acked. */
+function demoFetch(messageResponses: Array<() => Response>, suppliers?: () => unknown[]) {
+  const messageCalls: Array<Record<string, unknown>> = [];
+  const endCalls: string[] = [];
+  let i = 0;
+  const fetchFn = (async (url: unknown, init?: { body?: string; headers?: Record<string, string> }) => {
+    const u = String(url);
+    if (u.includes("/v1/chat/message")) {
+      messageCalls.push(init?.body ? (JSON.parse(init.body) as Record<string, unknown>) : {});
+      const make = messageResponses[Math.min(i, messageResponses.length - 1)];
+      i += 1;
+      return make();
+    }
+    if (u.includes("/v1/chat/end")) {
+      endCalls.push(init?.headers?.["X-Escrow-Ref"] ?? "");
+      return new Response(JSON.stringify({ status: "submitted" }), { status: 200 });
+    }
+    if (u.includes("/suppliers")) return new Response(JSON.stringify(suppliers ? suppliers() : SUPPLIERS), { status: 200 });
+    return new Response("[]", { status: 200 });
+  }) as unknown as typeof globalThis.fetch;
+  return { fetchFn, messageCalls, endCalls };
+}
+
+/** Insert a demo-flagged key directly (public signup can't mint one) and stub
+ * the SDK's chain-touching startChat on the pre-warmed per-key context. */
+function setupDemoKey(deps: GatewayDeps) {
+  const rawKey = `vk_test_${randomBytes(24).toString("hex")}`;
+  const privHex = genPrivKeyHex();
+  const walletKey = deriveWalletKey(privHex, 0);
+  const sealed = seal(privHex, MASTER);
+  deps.store.insertKey({
+    id: randomUUID(),
+    key_hash: hashApiKey(rawKey),
+    key_prefix: rawKey.slice(0, 12),
+    label: "shared-demo",
+    wallet_pkh: walletKey.pubKeyHash,
+    deposit_address: walletKey.address,
+    enc_priv_nonce: sealed.nonce,
+    enc_priv_ct: sealed.ct,
+    enc_priv_tag: sealed.tag,
+    master_key_version: 1,
+    created_at: Date.now(),
+    demo: 1,
+  });
+  const keyRow = deps.store.getKeyByHash(hashApiKey(rawKey))!;
+  const ctx = deps.registry.getContext(keyRow);
+  const startChat = vi.fn(async () => ({
+    escrowRef: { txHash: randomBytes(32).toString("hex"), index: 0 },
+    sessionNonce: "nonce",
+    supplierBaseUrl: "http://sup",
+  }));
+  (ctx.sdk as { startChat: unknown }).startChat = startChat;
+  return { rawKey, keyRow, startChat };
+}
+
+describe("gateway demo key", () => {
+  it("runs a session-backed completion with tools and reuses the session via affinity", async () => {
+    const { fetchFn, messageCalls } = demoFetch([
+      () => supplierSse([doneFrame({ role: "assistant", content: "", tool_calls: [TOOL_CALL] }, "tool_calls")]),
+      () => supplierSse([{ type: "token", value: "It is 3pm" }, doneFrame({ role: "assistant", content: "It is 3pm" }, "stop")]),
+    ]);
+    const deps = makeDeps(fetchFn, { chain: fundedChain });
+    const { rawKey, startChat } = setupDemoKey(deps);
+    const app = createApp(deps);
+
+    // Turn 1: model asks for a tool call.
+    const history: Array<Record<string, unknown>> = [{ role: "user", content: "what time is it?" }];
+    const res1 = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: history, tools: TOOLS });
+    expect(res1.status).toBe(200);
+    expect(res1.body.choices[0].message.tool_calls).toEqual([TOOL_CALL]);
+    expect(res1.body.choices[0].finish_reason).toBe("tool_calls");
+    expect(startChat).toHaveBeenCalledTimes(1);
+    // First turn replays the full history and forwards tools.
+    expect((messageCalls[0].messages as unknown[]).length).toBe(1);
+    expect(messageCalls[0].tools).toEqual(TOOLS);
+
+    // Turn 2: client echoes the assistant tool_calls + tool result.
+    history.push({ role: "assistant", content: "", tool_calls: [TOOL_CALL] });
+    history.push({ role: "tool", content: "3pm", tool_call_id: "call_1" });
+    const res2 = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: history, tools: TOOLS });
+    expect(res2.status).toBe(200);
+    expect(res2.body.choices[0].message.content).toBe("It is 3pm");
+    expect(res2.body.choices[0].finish_reason).toBe("stop");
+    // Affinity hit: no new session, only the unseen delta is forwarded.
+    expect(startChat).toHaveBeenCalledTimes(1);
+    const delta = messageCalls[1].messages as Array<{ role: string }>;
+    expect(delta).toHaveLength(1);
+    expect(delta[0].role).toBe("tool");
+  });
+
+  it("streams tool_calls chunks with finish_reason tool_calls", async () => {
+    const { fetchFn } = demoFetch([
+      () => supplierSse([doneFrame({ role: "assistant", content: "", tool_calls: [TOOL_CALL] }, "tool_calls")]),
+    ]);
+    const deps = makeDeps(fetchFn, { chain: fundedChain });
+    const { rawKey } = setupDemoKey(deps);
+    const res = await request(createApp(deps))
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: [{ role: "user", content: "time?" }], tools: TOOLS, stream: true });
+    expect(res.status).toBe(200);
+    const chunks = res.text
+      .split("\n\n")
+      .filter((l) => l.startsWith("data: ") && !l.includes("[DONE]"))
+      .map((l) => JSON.parse(l.slice(6)));
+    const toolChunk = chunks.find((c) => c.choices?.[0]?.delta?.tool_calls);
+    expect(toolChunk.choices[0].delta.tool_calls[0].function.name).toBe("get_time");
+    expect(chunks.at(-1).choices[0].finish_reason).toBe("tool_calls");
+    expect(res.text).toContain("data: [DONE]");
+  });
+
+  it("transparently reopens when the supplier lost the session (idle-close)", async () => {
+    const { fetchFn, messageCalls } = demoFetch([
+      () => supplierSse([{ type: "token", value: "Hi" }, doneFrame({ role: "assistant", content: "Hi" }, "stop")]),
+      () => new Response("not found", { status: 404 }),
+      () => supplierSse([{ type: "token", value: "Sure" }, doneFrame({ role: "assistant", content: "Sure" }, "stop")]),
+    ]);
+    const deps = makeDeps(fetchFn, { chain: fundedChain });
+    const { rawKey, startChat } = setupDemoKey(deps);
+    const app = createApp(deps);
+
+    const res1 = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: [{ role: "user", content: "hi" }] });
+    expect(res1.status).toBe(200);
+
+    // Extended history matches the session, but the supplier 404s the turn →
+    // the executor closes the session and reopens, replaying full history.
+    const history = [
+      { role: "user", content: "hi" },
+      { role: "assistant", content: "Hi" },
+      { role: "user", content: "more please" },
+    ];
+    const res2 = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: history });
+    expect(res2.status).toBe(200);
+    expect(res2.body.choices[0].message.content).toBe("Sure");
+    expect(startChat).toHaveBeenCalledTimes(2);
+    expect((messageCalls[2].messages as unknown[]).length).toBe(3);
+    // The dead session's fee was recorded for spend audit.
+    const usage = deps.store.listUsage(deps.store.listAllKeys().find((k) => k.demo === 1)!.id, 10);
+    expect(usage.some((u) => u.kind === "chat_session" && u.cost_lovelace === "1000000")).toBe(true);
+  });
+
+  it("rejects histories with nothing respondable before any chain work", async () => {
+    const deps = makeDeps(undefined, { chain: fundedChain });
+    const { rawKey, startChat } = setupDemoKey(deps);
+    const res = await request(createApp(deps))
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: [{ role: "assistant", content: "hello" }] });
+    expect(res.status).toBe(400);
+    expect(res.body.error.code).toBe("invalid_messages");
+    expect(startChat).not.toHaveBeenCalled();
+  });
+
+  it("answers a trailing-assistant history by trimming to the last user message (regenerate)", async () => {
+    const { fetchFn, messageCalls } = demoFetch([
+      () => supplierSse([{ type: "token", value: "Again" }, doneFrame({ role: "assistant", content: "Again" }, "stop")]),
+    ]);
+    const deps = makeDeps(fetchFn, { chain: fundedChain });
+    const { rawKey, startChat } = setupDemoKey(deps);
+    const res = await request(createApp(deps))
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({
+        model: "kimi",
+        messages: [
+          { role: "user", content: "hi" },
+          { role: "assistant", content: "partial answer" },
+        ],
+      });
+    expect(res.status).toBe(200);
+    expect(res.body.choices[0].message.content).toBe("Again");
+    expect(startChat).toHaveBeenCalledTimes(1);
+    // The trailing assistant message is dropped from the replay.
+    expect((messageCalls[0].messages as Array<{ role: string }>).map((m) => m.role)).toEqual(["user"]);
+  });
+
+  it("keeps the session when the client reshapes the assistant echo (lenient affinity)", async () => {
+    const { fetchFn, messageCalls } = demoFetch([
+      () => supplierSse([{ type: "token", value: "<think>hm</think>Hi  there" }, doneFrame({ role: "assistant", content: "<think>hm</think>Hi  there" }, "stop")]),
+      () => supplierSse([{ type: "token", value: "Sure" }, doneFrame({ role: "assistant", content: "Sure" }, "stop")]),
+    ]);
+    const deps = makeDeps(fetchFn, { chain: fundedChain });
+    const { rawKey, startChat } = setupDemoKey(deps);
+    const app = createApp(deps);
+
+    const res1 = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: [{ role: "user", content: "hi" }] });
+    expect(res1.status).toBe(200);
+
+    // Client echoes the assistant reply with the think block stripped and
+    // whitespace collapsed — still the same session, delta only.
+    const res2 = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({
+        model: "kimi",
+        messages: [
+          { role: "user", content: "hi" },
+          { role: "assistant", content: "Hi there" },
+          { role: "user", content: "more" },
+        ],
+      });
+    expect(res2.status).toBe(200);
+    expect(res2.body.choices[0].message.content).toBe("Sure");
+    expect(startChat).toHaveBeenCalledTimes(1);
+    expect((messageCalls[1].messages as unknown[]).length).toBe(1);
+  });
+
+  it("evicts the LRU demo session when every supplier is pinned", async () => {
+    const suppliers = [{ ...SUPPLIERS[1] }]; // single chat supplier, mutable status
+    const { fetchFn, messageCalls, endCalls } = demoFetch(
+      [
+        () => supplierSse([{ type: "token", value: "Hi" }, doneFrame({ role: "assistant", content: "Hi" }, "stop")]),
+        () => supplierSse([{ type: "token", value: "New" }, doneFrame({ role: "assistant", content: "New" }, "stop")]),
+      ],
+      () => suppliers,
+    );
+    const deps = makeDeps(fetchFn, { chain: fundedChain });
+    const { rawKey, startChat } = setupDemoKey(deps);
+    const app = createApp(deps);
+
+    const res1 = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: [{ role: "user", content: "hi" }] });
+    expect(res1.status).toBe(200);
+
+    // The lone supplier is now pinned by session 1 (indexer sees it working).
+    suppliers[0] = { ...suppliers[0], status: "working" };
+
+    // Unrelated history → affinity miss → no free supplier → evict session 1
+    // (supplier /v1/chat/end) and retry, bypassing the stale indexer status.
+    const res2 = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: [{ role: "user", content: "different topic" }] });
+    expect(res2.status).toBe(200);
+    expect(res2.body.choices[0].message.content).toBe("New");
+    expect(startChat).toHaveBeenCalledTimes(2);
+    expect(endCalls).toHaveLength(1);
+    expect((messageCalls[1].messages as unknown[]).length).toBe(1);
+    // Evicted session closed + billed.
+    const keyId = deps.store.listAllKeys().find((k) => k.demo === 1)!.id;
+    const usage = deps.store.listUsage(keyId, 10);
+    expect(usage.some((u) => u.kind === "chat_session" && u.cost_lovelace === "1000000")).toBe(true);
+    expect(deps.store.listOpenSessionsByKey(keyId)).toHaveLength(1); // only session 2
+  });
+
+  it("surfaces the original no-supplier error when there is nothing to evict", async () => {
+    const suppliers = [{ ...SUPPLIERS[1], status: "working" }];
+    const { fetchFn, endCalls } = demoFetch([() => new Response("unused", { status: 500 })], () => suppliers);
+    const deps = makeDeps(fetchFn, { chain: fundedChain });
+    const { rawKey, startChat } = setupDemoKey(deps);
+    const res = await request(createApp(deps))
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: [{ role: "user", content: "hi" }] });
+    expect(res.status).toBe(404);
+    expect(res.body.error.code).toBe("model_not_found");
+    expect(startChat).not.toHaveBeenCalled();
+    expect(endCalls).toHaveLength(0);
+  });
+
+  it("ticket mode: session close settles nothing and bills zero", async () => {
+    const { fetchFn } = demoFetch([
+      () => supplierSse([{ type: "token", value: "Hi" }, doneFrame({ role: "assistant", content: "Hi" }, "stop")]),
+    ]);
+    const deps = makeDeps(fetchFn, { chain: fundedChain, chatSettleMode: "ticket" });
+    const { rawKey, keyRow } = setupDemoKey(deps);
+    const ctx = deps.registry.getContext(keyRow);
+    const endChat = vi.fn(async (opts: { escrowRef: unknown }) => ({
+      settleMode: "ticket" as const,
+      escrowRef: opts.escrowRef,
+    }));
+    (ctx.sdk as { endChat: unknown }).endChat = endChat;
+    const app = createApp(deps);
+
+    const res1 = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: [{ role: "user", content: "hi" }] });
+    expect(res1.status).toBe(200);
+
+    const session = deps.store.listOpenSessionsByKey(keyRow.id)[0];
+    const close = await request(app)
+      .post(`/openai/v1/chat/sessions/${session.id}/close`)
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({});
+    expect(close.status).toBe(200);
+    expect(close.body.settle_mode).toBe("ticket");
+    expect(close.body.accepted_ref).toBeUndefined();
+    expect(endChat).toHaveBeenCalledTimes(1);
+
+    const usage = deps.store.listUsage(keyRow.id, 10);
+    expect(usage.some((u) => u.kind === "chat_session" && u.cost_lovelace === "0")).toBe(true);
+  });
+
+  it("ticket mode: janitor-closed demo sessions bill zero", async () => {
+    const { fetchFn, endCalls } = demoFetch([
+      () => supplierSse([{ type: "token", value: "Hi" }, doneFrame({ role: "assistant", content: "Hi" }, "stop")]),
+    ]);
+    const deps = makeDeps(fetchFn, { chain: fundedChain, chatSettleMode: "ticket" });
+    const { rawKey, keyRow } = setupDemoKey(deps);
+    const app = createApp(deps);
+
+    const res = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: [{ role: "user", content: "hi" }] });
+    expect(res.status).toBe(200);
+
+    await sweepIdleDemoSessions(deps, Date.now() + deps.config.demoSessionIdleMs + 1);
+    expect(endCalls.length).toBeGreaterThan(0);
+    const usage = deps.store.listUsage(keyRow.id, 10);
+    expect(usage.some((u) => u.kind === "chat_session" && u.cost_lovelace === "0")).toBe(true);
+  });
+
+  it("janitor closes idle demo sessions so the next request opens fresh", async () => {
+    const { fetchFn, messageCalls, endCalls } = demoFetch([
+      () => supplierSse([{ type: "token", value: "Hi" }, doneFrame({ role: "assistant", content: "Hi" }, "stop")]),
+      () => supplierSse([{ type: "token", value: "Fresh" }, doneFrame({ role: "assistant", content: "Fresh" }, "stop")]),
+    ]);
+    const deps = makeDeps(fetchFn, { chain: fundedChain });
+    const { rawKey, startChat } = setupDemoKey(deps);
+    const app = createApp(deps);
+
+    const res1 = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ model: "kimi", messages: [{ role: "user", content: "hi" }] });
+    expect(res1.status).toBe(200);
+
+    // Pretend demoSessionIdleMs elapsed: the sweeper tick closes the session.
+    await sweepIdleDemoSessions(deps, Date.now() + deps.config.demoSessionIdleMs + 1);
+    expect(endCalls).toHaveLength(1);
+    const keyId = deps.store.listAllKeys().find((k) => k.demo === 1)!.id;
+    expect(deps.store.listOpenSessionsByKey(keyId)).toHaveLength(0);
+
+    // Continuing the thread now misses affinity and reopens with full replay.
+    const res2 = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({
+        model: "kimi",
+        messages: [
+          { role: "user", content: "hi" },
+          { role: "assistant", content: "Hi" },
+          { role: "user", content: "more" },
+        ],
+      });
+    expect(res2.status).toBe(200);
+    expect(startChat).toHaveBeenCalledTimes(2);
+    expect((messageCalls[1].messages as unknown[]).length).toBe(3);
+  });
+
+  it("blocks withdraw and hides the deposit address for demo keys", async () => {
+    const deps = makeDeps();
+    const { rawKey } = setupDemoKey(deps);
+    const app = createApp(deps);
+
+    const wd = await request(app)
+      .post("/account/withdraw")
+      .set("authorization", `Bearer ${rawKey}`)
+      .send({ to_address: "addr_test1abc" });
+    expect(wd.status).toBe(403);
+    expect(wd.body.error.code).toBe("demo_key_restricted");
+
+    const acct = await request(app).get("/account").set("authorization", `Bearer ${rawKey}`);
+    expect(acct.status).toBe(200);
+    expect(acct.body.deposit_address).toBeNull();
+    expect(acct.body.demo).toBe(true);
+  });
+
+  it("lists only chat-capable models for demo keys", async () => {
+    const fetchFn = (async (url: unknown) =>
+      new Response(JSON.stringify(String(url).includes("/suppliers") ? SUPPLIERS.filter((s) => !String(url).includes("capability_id") || s.capability_id === "llm.chat.v1") : []), { status: 200 })) as unknown as typeof globalThis.fetch;
+    const deps = makeDeps(fetchFn);
+    const { rawKey } = setupDemoKey(deps);
+    const app = createApp(deps);
+
+    const demoModels = await request(app).get("/openai/v1/models").set("authorization", `Bearer ${rawKey}`);
+    expect(demoModels.body.data.map((m: { id: string }) => m.id)).toEqual(["kimi"]);
+
+    const signup = await request(app).post("/signup").send({});
+    const normalModels = await request(app).get("/openai/v1/models").set("authorization", `Bearer ${signup.body.api_key as string}`);
+    expect(normalModels.body.data.map((m: { id: string }) => m.id).sort()).toEqual(["kimi", "qwen"]);
+  });
+
+  it("rate-limits demo requests per IP (and not per key)", async () => {
+    const deps = makeDeps(undefined, { demoIpRate: { max: 1, windowMs: 60_000 } });
+    const { rawKey } = setupDemoKey(deps);
+    const app = createApp(deps);
+
+    // Model with no chat suppliers → cheap 404 AFTER passing the limiter.
+    const body = { model: "nope", messages: [{ role: "user", content: "hi" }] };
+    const first = await request(app).post("/openai/v1/chat/completions").set("authorization", `Bearer ${rawKey}`).send(body);
+    expect(first.status).toBe(404);
+    const second = await request(app).post("/openai/v1/chat/completions").set("authorization", `Bearer ${rawKey}`).send(body);
+    expect(second.status).toBe(429);
+
+    // Non-demo keys are untouched by the demo IP limiter.
+    const signup = await request(app).post("/signup").send({});
+    const normal = await request(app)
+      .post("/openai/v1/chat/completions")
+      .set("authorization", `Bearer ${signup.body.api_key as string}`)
+      .send(body);
+    expect(normal.status).not.toBe(429);
+  });
+});

gateway/test/migration.test.ts

@@ -0,0 +1,79 @@
+/**
+ * migration.test.ts — the demo-column migration on pre-existing databases.
+ *
+ * GatewayStore has no migration framework (pure CREATE TABLE IF NOT EXISTS),
+ * so opening a DB created before the `demo` column must ALTER it in place.
+ */
+
+import { describe, it, expect } from "vitest";
+import { tmpdir } from "os";
+import { join } from "path";
+import { mkdirSync } from "fs";
+import { randomUUID } from "crypto";
+import Database from "better-sqlite3";
+import { GatewayStore } from "../src/db/store.js";
+
+const LEGACY_API_KEYS_SQL = `
+CREATE TABLE IF NOT EXISTS api_keys (
+  id                 TEXT PRIMARY KEY,
+  key_hash           TEXT NOT NULL UNIQUE,
+  key_prefix         TEXT NOT NULL,
+  label              TEXT,
+  wallet_pkh         TEXT NOT NULL,
+  deposit_address    TEXT NOT NULL,
+  enc_priv_nonce     TEXT NOT NULL,
+  enc_priv_ct        TEXT NOT NULL,
+  enc_priv_tag       TEXT NOT NULL,
+  master_key_version INTEGER NOT NULL DEFAULT 1,
+  created_at         INTEGER NOT NULL,
+  disabled           INTEGER NOT NULL DEFAULT 0
+);
+`;
+
+function keyRow(id: string) {
+  return {
+    id,
+    key_hash: `hash-${id}`,
+    key_prefix: "vk_test_xxxx",
+    label: null,
+    wallet_pkh: "pkh",
+    deposit_address: "addr_test1x",
+    enc_priv_nonce: "n",
+    enc_priv_ct: "c",
+    enc_priv_tag: "t",
+    master_key_version: 1,
+    created_at: Date.now(),
+  };
+}
+
+describe("GatewayStore demo-column migration", () => {
+  it("adds the demo column to a legacy DB and defaults existing keys to 0", () => {
+    const dir = join(tmpdir(), `gw-mig-${randomUUID()}`);
+    mkdirSync(dir, { recursive: true });
+    const raw = new Database(join(dir, "gateway.db"));
+    raw.exec(LEGACY_API_KEYS_SQL);
+    raw
+      .prepare(
+        `INSERT INTO api_keys (id, key_hash, key_prefix, label, wallet_pkh, deposit_address,
+         enc_priv_nonce, enc_priv_ct, enc_priv_tag, master_key_version, created_at, disabled)
+         VALUES (@id, @key_hash, @key_prefix, @label, @wallet_pkh, @deposit_address,
+         @enc_priv_nonce, @enc_priv_ct, @enc_priv_tag, @master_key_version, @created_at, 0)`,
+      )
+      .run(keyRow("legacy"));
+    raw.close();
+
+    const store = new GatewayStore(dir);
+    const legacy = store.getKeyByHash("hash-legacy");
+    expect(legacy?.demo).toBe(0);
+
+    store.insertKey({ ...keyRow("demo-key"), demo: 1 });
+    expect(store.getKeyByHash("hash-demo-key")?.demo).toBe(1);
+  });
+
+  it("persists the demo flag on fresh databases (default 0)", () => {
+    const dir = join(tmpdir(), `gw-fresh-${randomUUID()}`);
+    const store = new GatewayStore(dir);
+    store.insertKey(keyRow("plain"));
+    expect(store.getKeyByHash("hash-plain")?.demo).toBe(0);
+  });
+});

gateway/test/sweeper.test.ts

@@ -0,0 +1,186 @@
+/**
+ * sweeper.test.ts — reclaim/close decoupling + settled-refs memory.
+ *
+ * Ticket mode: reclaiming a live session's Open escrow must NOT close the
+ * session row or drop its transcript mirror (the conversation continues on a
+ * spent ticket). Full mode keeps close-on-reclaim. Claimed rows close even
+ * under ticket config (they can only come from full-mode suppliers). The
+ * settled-refs memory prevents re-attempting refs already settled, and the
+ * deliver_by gate skips reclaims the validator would reject.
+ */
+
+import { describe, it, expect, vi } from "vitest";
+import { tmpdir } from "os";
+import { join } from "path";
+import { randomBytes, randomUUID } from "crypto";
+import { GatewayStore } from "../src/db/store.js";
+import { SdkRegistry } from "../src/sdk/registry.js";
+import { genPrivKeyHex, deriveWalletKey } from "../src/wallet.js";
+import { seal } from "../src/crypto/seal.js";
+import { hashApiKey } from "../src/middleware/apiKeyAuth.js";
+import { runSweepOnce } from "../src/sweeper.js";
+import { transcripts } from "../src/openai/transcripts.js";
+import type { GatewayConfig } from "../src/config.js";
+import type { GatewayDeps } from "../src/deps.js";
+import type { EscrowRow } from "../src/onchain/settle.js";
+
+const MASTER = "ab".repeat(32);
+
+function makeSweepDeps(opts: { chatSettleMode: "full" | "ticket"; escrows: EscrowRow[] }) {
+  const dbDir = join(tmpdir(), `gw-sweep-${randomUUID()}`);
+  const store = new GatewayStore(dbDir);
+  const config: GatewayConfig = {
+    masterKeyHex: MASTER,
+    indexerUrl: "http://ix",
+    ogmiosUrl: "http://og",
+    networkId: 0,
+    liveChain: true,
+    port: 0,
+    dbDir,
+    signupRate: { max: 1000, windowMs: 60_000 },
+    keyRate: { max: 1000, windowMs: 60_000 },
+    demoIpRate: { max: 1000, windowMs: 60_000 },
+    sweeperIntervalMs: 60_000,
+    demoSessionIdleMs: 180_000,
+    chatSettleMode: opts.chatSettleMode,
+    walletHealthIntervalMs: 600_000,
+    sdkRegistryMax: 100,
+    corsOrigins: [],
+  };
+  const chain = { queryUtxo: async () => null } as unknown as GatewayDeps["chain"];
+  const registry = new SdkRegistry({
+    chain,
+    indexerUrl: config.indexerUrl,
+    networkId: config.networkId,
+    masterKeyHex: config.masterKeyHex,
+    max: config.sdkRegistryMax,
+  });
+  const fetchFn = (async (url: unknown) => {
+    if (String(url).includes("/escrows")) return new Response(JSON.stringify(opts.escrows), { status: 200 });
+    return new Response("[]", { status: 200 });
+  }) as unknown as typeof globalThis.fetch;
+  const deps: GatewayDeps = { config, store, chain, registry, fetchFn };
+
+  const rawKey = `vk_test_${randomBytes(24).toString("hex")}`;
+  const privHex = genPrivKeyHex();
+  const walletKey = deriveWalletKey(privHex, 0);
+  const sealed = seal(privHex, MASTER);
+  store.insertKey({
+    id: randomUUID(),
+    key_hash: hashApiKey(rawKey),
+    key_prefix: rawKey.slice(0, 12),
+    label: "sweep-test",
+    wallet_pkh: walletKey.pubKeyHash,
+    deposit_address: walletKey.address,
+    enc_priv_nonce: sealed.nonce,
+    enc_priv_ct: sealed.ct,
+    enc_priv_tag: sealed.tag,
+    master_key_version: 1,
+    created_at: Date.now(),
+    demo: 1,
+  });
+  const keyRow = store.getKeyByHash(hashApiKey(rawKey))!;
+  return { deps, keyRow };
+}
+
+function insertOpenSession(deps: GatewayDeps, keyId: string, escrowRef: string): string {
+  const id = randomUUID();
+  deps.store.insertSession({
+    id,
+    key_id: keyId,
+    escrow_ref: escrowRef,
+    session_nonce: "nonce",
+    supplier_base_url: "http://sup",
+    supplier_pkh: "s1",
+    model: "kimi",
+    price_lovelace: "200000",
+    state: "open",
+    opened_at: Date.now() - 40 * 60 * 1000,
+  });
+  return id;
+}
+
+function openRow(refChar: string, opts?: Partial<EscrowRow>): EscrowRow {
+  return {
+    utxo_ref: `${refChar.repeat(64)}#0`,
+    state: "Open",
+    posted_at: Date.now() - 40 * 60 * 1000,
+    deliver_by: Date.now() - 5 * 60 * 1000,
+    ...opts,
+  };
+}
+
+const settleOk = () => ({
+  accept: vi.fn(async () => undefined) as never,
+  reclaim: vi.fn(async () => undefined) as never,
+});
+
+describe("sweeper — ticket-mode reclaim/close decoupling", () => {
+  it("reclaims a live session's Open ticket but keeps the session (and mirror) alive", async () => {
+    const row = openRow("1");
+    const { deps, keyRow } = makeSweepDeps({ chatSettleMode: "ticket", escrows: [row] });
+    const sessionId = insertOpenSession(deps, keyRow.id, row.utxo_ref);
+    transcripts.set(sessionId, [{ role: "user", content: "hi" }]);
+    const settle = settleOk();
+
+    await runSweepOnce(deps, settle);
+
+    expect(settle.reclaim).toHaveBeenCalledTimes(1);
+    expect(deps.store.getSession(sessionId)!.state).toBe("open"); // NOT closed
+    expect(transcripts.get(sessionId)).toBeDefined(); // mirror intact
+    expect(deps.store.listUsage(keyRow.id, 10)).toHaveLength(0); // nothing billed
+
+    transcripts.delete(sessionId);
+  });
+
+  it("full mode: reclaim closes the session row", async () => {
+    const row = openRow("2");
+    const { deps, keyRow } = makeSweepDeps({ chatSettleMode: "full", escrows: [row] });
+    const sessionId = insertOpenSession(deps, keyRow.id, row.utxo_ref);
+    const settle = settleOk();
+
+    await runSweepOnce(deps, settle);
+
+    expect(settle.reclaim).toHaveBeenCalledTimes(1);
+    expect(deps.store.getSession(sessionId)!.state).toBe("closed");
+    const usage = deps.store.listUsage(keyRow.id, 10);
+    expect(usage.some((u) => u.status === "reclaimed")).toBe(true);
+  });
+
+  it("ticket config still closes sessions behind Claimed rows (full-mode suppliers)", async () => {
+    const row = openRow("3", { state: "Claimed" });
+    const { deps, keyRow } = makeSweepDeps({ chatSettleMode: "ticket", escrows: [row] });
+    const sessionId = insertOpenSession(deps, keyRow.id, row.utxo_ref);
+    const settle = settleOk();
+
+    await runSweepOnce(deps, settle);
+
+    expect(settle.reclaim).toHaveBeenCalledTimes(1);
+    expect(deps.store.getSession(sessionId)!.state).toBe("closed");
+  });
+});
+
+describe("sweeper — reclaim gating + settled-refs memory", () => {
+  it("skips reclaim while deliver_by has not passed", async () => {
+    const row = openRow("4", { deliver_by: Date.now() + 10 * 60 * 1000 });
+    const { deps, keyRow } = makeSweepDeps({ chatSettleMode: "ticket", escrows: [row] });
+    insertOpenSession(deps, keyRow.id, row.utxo_ref);
+    const settle = settleOk();
+
+    await runSweepOnce(deps, settle);
+
+    expect(settle.reclaim).not.toHaveBeenCalled();
+  });
+
+  it("does not re-attempt refs it already settled (in-process memory)", async () => {
+    const row = openRow("5");
+    const { deps, keyRow } = makeSweepDeps({ chatSettleMode: "ticket", escrows: [row] });
+    insertOpenSession(deps, keyRow.id, row.utxo_ref);
+    const settle = settleOk();
+
+    await runSweepOnce(deps, settle);
+    await runSweepOnce(deps, settle);
+
+    expect(settle.reclaim).toHaveBeenCalledTimes(1);
+  });
+});

gateway/test/unit.test.ts

@@ -0,0 +1,223 @@
+import { describe, it, expect } from "vitest";
+import { seal, open } from "../src/crypto/seal.js";
+import { Mutex } from "../src/sdk/registry.js";
+import { selectCandidates, listModels, parseRef } from "../src/routing/selectSupplier.js";
+import { parseChatRequest } from "../src/openai/validate.js";
+import { buildChatCompletion, buildChunk, usageFromReceipt, renderMessages } from "../src/openai/shapes.js";
+import { totalLovelace, hasCollateral, preflight } from "../src/onchain/preflight.js";
+import { GatewayError } from "../src/openai/errors.js";
+
+const MASTER = "ab".repeat(32); // 64 hex
+
+const delay = (ms: number) => new Promise((r) => setTimeout(r, ms));
+
+function jsonResponse(body: unknown): typeof globalThis.fetch {
+  return (async () => new Response(JSON.stringify(body), { status: 200 })) as unknown as typeof globalThis.fetch;
+}
+
+describe("crypto/seal", () => {
+  it("round-trips and binds the master key", () => {
+    const priv = "cd".repeat(32);
+    const sealed = seal(priv, MASTER);
+    expect(open(sealed, MASTER)).toBe(priv);
+    // Wrong key fails the GCM auth tag.
+    expect(() => open(sealed, "ff".repeat(32))).toThrow();
+    // Tampered ciphertext fails.
+    expect(() => open({ ...sealed, ct: sealed.ct.replace(/.$/, "0") }, MASTER)).toThrow();
+  });
+});
+
+describe("Mutex", () => {
+  it("serializes in submission order and survives rejection", async () => {
+    const m = new Mutex();
+    const order: number[] = [];
+    const p1 = m.run(async () => {
+      await delay(20);
+      order.push(1);
+    });
+    const p2 = m.run(async () => {
+      order.push(2);
+    });
+    await Promise.all([p1, p2]);
+    expect(order).toEqual([1, 2]);
+
+    await m.run(async () => {
+      throw new Error("boom");
+    }).catch(() => undefined);
+    expect(await m.run(async () => 42)).toBe(42);
+  });
+});
+
+describe("routing/selectSupplier", () => {
+  const rows = [
+    { utxo_ref: "aa".repeat(32) + "#0", supplier_pkh: "s1", capability_id: "llm.text.generate.v1", model: "m", max_output_tokens: 1, price_lovelace: "2", supplier_bond_lovelace: "1", buyer_bond_lovelace: "1", endpoint_url: "http://a", advert_status: "Active", status: "free" },
+    { utxo_ref: "bb".repeat(32) + "#1", supplier_pkh: "s2", capability_id: "llm.text.generate.v1", model: "m", max_output_tokens: 1, price_lovelace: "9", supplier_bond_lovelace: "1", buyer_bond_lovelace: "1", endpoint_url: "http://b", advert_status: "Active", status: "unknown" },
+    { utxo_ref: "cc".repeat(32) + "#0", supplier_pkh: "s3", capability_id: "llm.text.generate.v1", model: "m", max_output_tokens: 1, price_lovelace: "1", supplier_bond_lovelace: "1", buyer_bond_lovelace: "1", endpoint_url: "http://c", advert_status: "Retired", status: "free" },
+    { utxo_ref: "dd".repeat(32) + "#0", supplier_pkh: "s4", capability_id: "llm.chat.v1", model: "m", max_output_tokens: 1, price_lovelace: "1", supplier_bond_lovelace: "1", buyer_bond_lovelace: "1", endpoint_url: "http://d", advert_status: "Active", status: "free" },
+    { utxo_ref: "ee".repeat(32) + "#0", supplier_pkh: "s5", capability_id: "llm.text.generate.v1", model: "other", max_output_tokens: 1, price_lovelace: "1", supplier_bond_lovelace: "1", buyer_bond_lovelace: "1", endpoint_url: "http://e", advert_status: "Active", status: "free" },
+  ];
+
+  it("matches capability + model + Active + (free|unknown), free first", async () => {
+    const got = await selectCandidates({
+      indexerUrl: "http://ix",
+      model: "m",
+      capabilityId: "llm.text.generate.v1",
+      fetchFn: jsonResponse(rows),
+    });
+    expect(got.map((c) => c.supplierPkh)).toEqual(["s1", "s2"]); // s3 Retired, s4 chat, s5 other model
+    expect(got[0].status).toBe("free");
+    expect(got[1].status).toBe("unknown");
+    expect(got[0].priceLovelace).toBe(2n);
+  });
+
+  it("routes chat.v1 separately", async () => {
+    const got = await selectCandidates({
+      indexerUrl: "http://ix",
+      model: "m",
+      capabilityId: "llm.chat.v1",
+      fetchFn: jsonResponse(rows),
+    });
+    expect(got.map((c) => c.supplierPkh)).toEqual(["s4"]);
+  });
+
+  it("lists distinct Active models", async () => {
+    expect(await listModels({ indexerUrl: "http://ix", fetchFn: jsonResponse(rows) })).toEqual(["m", "other"]);
+  });
+
+  it("lists only one capability's models when capabilityId is given", async () => {
+    expect(await listModels({ indexerUrl: "http://ix", capabilityId: "llm.chat.v1", fetchFn: jsonResponse(rows) })).toEqual(["m"]);
+  });
+
+  it("parseRef", () => {
+    expect(parseRef("aa".repeat(32) + "#3")).toEqual({ txHash: "aa".repeat(32), index: 3 });
+    expect(parseRef("nope")).toBeNull();
+  });
+
+  it("ignoreStatusFor readmits a busy supplier by pkh (stale indexer status)", async () => {
+    const busy = [
+      { ...rows[0], status: "working" },
+      { ...rows[1], status: "offline" },
+    ];
+    const base = { indexerUrl: "http://ix", model: "m", capabilityId: "llm.text.generate.v1" };
+    const excluded = await selectCandidates({ ...base, fetchFn: jsonResponse(busy) });
+    expect(excluded).toEqual([]);
+
+    const readmitted = await selectCandidates({
+      ...base,
+      fetchFn: jsonResponse(busy),
+      ignoreStatusFor: new Set(["s1"]),
+    });
+    expect(readmitted.map((c) => c.supplierPkh)).toEqual(["s1"]);
+  });
+});
+
+describe("openai/validate", () => {
+  it("accepts a valid body and ignores temperature", () => {
+    const p = parseChatRequest({ model: "m", messages: [{ role: "user", content: "hi" }], temperature: 0.7, max_tokens: 50 });
+    expect(p.model).toBe("m");
+    expect(p.maxTokens).toBe(50);
+    expect(p.stream).toBe(false);
+  });
+  it("rejects tools/functions", () => {
+    expect(() => parseChatRequest({ model: "m", messages: [{ role: "user", content: "x" }], tools: [] })).toThrow(GatewayError);
+  });
+  it("rejects empty messages and bad model", () => {
+    expect(() => parseChatRequest({ model: "m", messages: [] })).toThrow();
+    expect(() => parseChatRequest({ messages: [{ role: "user", content: "x" }] })).toThrow();
+  });
+
+  const TOOL_CALL = { id: "call_1", type: "function", function: { name: "get_time", arguments: "{}" } };
+
+  it("allowTools accepts tools, tool role, null content and assistant tool_calls", () => {
+    const p = parseChatRequest(
+      {
+        model: "m",
+        messages: [
+          { role: "user", content: "hi" },
+          { role: "assistant", content: null, tool_calls: [TOOL_CALL] },
+          { role: "tool", content: "3pm", tool_call_id: "call_1" },
+        ],
+        tools: [{ type: "function", function: { name: "get_time", parameters: {} } }],
+        tool_choice: "auto",
+      },
+      { allowTools: true },
+    );
+    expect(p.tools).toHaveLength(1);
+    expect(p.toolChoice).toBe("auto");
+    expect(p.messages[1]).toEqual({ role: "assistant", content: "", tool_calls: [TOOL_CALL] });
+    expect(p.messages[2]).toEqual({ role: "tool", content: "3pm", tool_call_id: "call_1" });
+  });
+
+  it("allowTools still rejects legacy functions and the default path still rejects tool role", () => {
+    expect(() =>
+      parseChatRequest({ model: "m", messages: [{ role: "user", content: "x" }], functions: [] }, { allowTools: true }),
+    ).toThrow(GatewayError);
+    expect(() =>
+      parseChatRequest({ model: "m", messages: [{ role: "tool", content: "x", tool_call_id: "c" }] }),
+    ).toThrow(GatewayError);
+  });
+});
+
+describe("openai/shapes", () => {
+  const receipt = { prompt_hash: "p", response_hash: "r", model: "m", prompt_tokens: 3, completion_tokens: 5, wallclock_ms: 1, supplier_pkh: "s", escrow_ref: "x#0" };
+  it("usage + completion shape", () => {
+    const usage = usageFromReceipt(receipt);
+    expect(usage).toEqual({ prompt_tokens: 3, completion_tokens: 5, total_tokens: 8 });
+    const cc = buildChatCompletion({ id: "id", model: "m", content: "hello", usage, vector: { receipt, receipt_signature: "sig", escrow_ref: "x#0" } });
+    expect(cc.object).toBe("chat.completion");
+    expect((cc.choices as any)[0].message).toEqual({ role: "assistant", content: "hello" });
+    expect((cc as any).x_vector.escrow_ref).toBe("x#0");
+  });
+  it("chunk shape", () => {
+    const ch = buildChunk({ id: "id", model: "m", delta: { content: "tok" }, finishReason: null });
+    expect(ch.object).toBe("chat.completion.chunk");
+    expect((ch.choices as any)[0].delta.content).toBe("tok");
+  });
+  it("tool_calls chunk + finish_reason tool_calls", () => {
+    const tc = { index: 0, id: "call_1", type: "function" as const, function: { name: "f", arguments: "{}" } };
+    const ch = buildChunk({ id: "id", model: "m", delta: { tool_calls: [tc] }, finishReason: "tool_calls" });
+    expect((ch.choices as any)[0].delta.tool_calls).toEqual([tc]);
+    expect((ch.choices as any)[0].finish_reason).toBe("tool_calls");
+  });
+  it("completion with tool_calls and finish_reason", () => {
+    const cc = buildChatCompletion({
+      id: "id",
+      model: "m",
+      content: "",
+      usage: { prompt_tokens: 1, completion_tokens: 1, total_tokens: 2 },
+      toolCalls: [{ id: "call_1", type: "function", function: { name: "f", arguments: "{}" } }],
+      finishReason: "tool_calls",
+    });
+    expect((cc.choices as any)[0].message.tool_calls).toHaveLength(1);
+    expect((cc.choices as any)[0].finish_reason).toBe("tool_calls");
+  });
+  it("renderMessages folds roles", () => {
+    expect(renderMessages([{ role: "system", content: "be nice" }, { role: "user", content: "hi" }])).toBe("System: be nice\n\nUser: hi");
+  });
+});
+
+describe("onchain/preflight", () => {
+  const pure = (lov: bigint) => ({ ref: { txHash: "x", index: 0 }, address: "a", lovelace: lov, assets: {}, datumHex: null, scriptRef: null });
+  const mixed = (lov: bigint) => ({ ...pure(lov), assets: { "policy.tok": 1n } });
+
+  it("totalLovelace + hasCollateral", () => {
+    expect(totalLovelace([pure(3_000_000n), pure(4_000_000n)])).toBe(7_000_000n);
+    expect(hasCollateral([pure(4_000_000n)])).toBe(false); // < 5 ADA
+    expect(hasCollateral([mixed(6_000_000n)])).toBe(false); // has native asset
+    expect(hasCollateral([pure(6_000_000n)])).toBe(true);
+  });
+
+  it("preflight requires balance AND collateral", async () => {
+    const cost = { priceLovelace: 2_000_000n, buyerBondLovelace: 1_000_000n, supplierBondLovelace: 1_000_000n };
+    // required = 2 + 1 + 1 + 5 (collateral) + 2 (fee) = 11 ADA
+    const fakeChain = { queryUtxosByAddress: async () => [pure(20_000_000n)] } as any;
+    const ok = await preflight(fakeChain, "a", cost);
+    expect(ok.ok).toBe(true);
+    expect(ok.requiredLovelace).toBe(11_000_000n);
+
+    const poor = { queryUtxosByAddress: async () => [pure(4_000_000n)] } as any;
+    const bad = await preflight(poor, "a", cost);
+    expect(bad.ok).toBe(false);
+    expect(bad.collateralOk).toBe(false);
+  });
+});

gateway/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "./src",
+    "outDir": "./dist",
+    "lib": ["ES2022"]
+  },
+  "include": ["src/**/*.ts"]
+}

package.json

@@ -37,5 +37,10 @@
     "tsx": "^4.19.2",
     "typescript": "^5.7.2",
     "vitest": "^2.1.8"
+  },
+  "pnpm": {
+    "patchedDependencies": {
+      "libsodium-wrappers-sumo@0.7.16": "patches/libsodium-wrappers-sumo@0.7.16.patch"
+    }
   }
 }

packages/shared/src/tx/chatMessage.ts

@@ -0,0 +1,88 @@
+/**
+ * tx/chatMessage.ts — canonical ChatMessage normalization + equivalence.
+ *
+ * The supplier's session transcript and the gateway's in-memory mirror must be
+ * hash-identical (receipt response_hash = sha256(canonicalize(transcript))),
+ * so both sides build messages through normalizeChatMessage: optional fields
+ * are truly absent when empty, content is never null, and vendor extras are
+ * stripped. chatMessagesEquivalent is the tolerant comparison used by the
+ * demo-endpoint transcript-prefix affinity matcher.
+ */
+
+import type { ChatMessage, ToolCall } from "./types.js";
+
+const ROLES = new Set(["system", "user", "assistant", "tool"]);
+
+function normalizeToolCall(raw: unknown): ToolCall | null {
+  if (typeof raw !== "object" || raw === null) return null;
+  const tc = raw as Record<string, unknown>;
+  const fn = tc.function as Record<string, unknown> | undefined;
+  if (typeof tc.id !== "string" || tc.id === "") return null;
+  if (tc.type !== "function") return null;
+  if (typeof fn !== "object" || fn === null) return null;
+  if (typeof fn.name !== "string" || fn.name === "") return null;
+  if (typeof fn.arguments !== "string") return null;
+  return { id: tc.id, type: "function", function: { name: fn.name, arguments: fn.arguments } };
+}
+
+/**
+ * Validate and canonicalize an untrusted message-shaped value.
+ * Returns null when the value is not a usable ChatMessage.
+ */
+export function normalizeChatMessage(raw: unknown): ChatMessage | null {
+  if (typeof raw !== "object" || raw === null) return null;
+  const m = raw as Record<string, unknown>;
+  if (typeof m.role !== "string" || !ROLES.has(m.role)) return null;
+  const role = m.role as ChatMessage["role"];
+
+  let content: string;
+  if (typeof m.content === "string") content = m.content;
+  else if (m.content === null || m.content === undefined) content = "";
+  else return null;
+
+  const msg: ChatMessage = { role, content };
+
+  if (m.tool_calls !== undefined && m.tool_calls !== null) {
+    if (role !== "assistant" || !Array.isArray(m.tool_calls)) return null;
+    const calls: ToolCall[] = [];
+    for (const raw of m.tool_calls) {
+      const tc = normalizeToolCall(raw);
+      if (!tc) return null;
+      calls.push(tc);
+    }
+    if (calls.length > 0) msg.tool_calls = calls;
+  }
+
+  if (m.tool_call_id !== undefined && m.tool_call_id !== null) {
+    if (role !== "tool" || typeof m.tool_call_id !== "string" || m.tool_call_id === "") return null;
+    msg.tool_call_id = m.tool_call_id;
+  }
+  if (role === "tool" && msg.tool_call_id === undefined) return null;
+
+  return msg;
+}
+
+export function toolCallsEqual(a?: ToolCall[], b?: ToolCall[]): boolean {
+  const la = a ?? [];
+  const lb = b ?? [];
+  if (la.length !== lb.length) return false;
+  return la.every((tc, i) =>
+    tc.id === lb[i].id &&
+    tc.function.name === lb[i].function.name &&
+    tc.function.arguments === lb[i].function.arguments,
+  );
+}
+
+/**
+ * Tolerant equality for affinity prefix matching. Both sides are expected to
+ * already be normalized; comparison ignores incidental key order and treats
+ * missing tool fields as empty.
+ */
+export function chatMessagesEquivalent(a: ChatMessage, b: ChatMessage): boolean {
+  return (
+    a.role === b.role &&
+    a.content === b.content &&
+    (a.tool_call_id ?? "") === (b.tool_call_id ?? "") &&
+    toolCallsEqual(a.tool_calls, b.tool_calls)
+  );
+}

packages/shared/src/tx/escrow/postChatEscrow.ts

@@ -42,6 +42,7 @@ import { loadBlueprint } from "../blueprint.js";
 import { encodeTxBody, sha256Hex } from "../internal/testTxBody.js";
 import { mockSlotToWallclockMs, NETWORK_BUFFER_MS } from "../internal/constants.js";
 import { detectCborBackend } from "../internal/cborBackend.js";
+import { escrowLockFloor } from "../internal/minAdaFloor.js";
 import type { LiveOgmiosProvider } from "../../chain/LiveOgmiosProvider.js";
 
 export interface PostChatEscrowParams {
@@ -132,7 +133,7 @@ export async function buildPostChatEscrowTx(
   const requestSpecHash = sha256Utf8Hex(requestSpecCanonical);
   const promptHash = chatSessionPromptHash({ session_nonce });
 
-  const totalLocked =
+  const economicTotal =
     advertDatum.price_lovelace +
     advertDatum.buyer_bond_lovelace +
     advertDatum.supplier_bond_lovelace;
@@ -154,6 +155,11 @@ export async function buildPostChatEscrowTx(
     state: "Open",
   };
 
+  // Lock enough that the escrow output satisfies min-ada in its LARGEST
+  // future state (Submitted) - value_equal on Claim/Submit forbids any
+  // later bump (min-ada floor).
+  const totalLocked = escrowLockFloor(escrowDatum, economicTotal);
+
   // Live path: reuse the capability-agnostic chat builder (messages = []).
   // The on-chain commitment is the escrowDatum (carrying our session-init
   // prompt_hash); messages are only used for the mock cbor body, which we omit.

packages/shared/src/tx/escrow/postEscrow.ts

@@ -38,6 +38,7 @@ import { loadBlueprint } from "../blueprint.js";
 import { encodeTxBody, sha256Hex } from "../internal/testTxBody.js";
 import { mockSlotToWallclockMs, NETWORK_BUFFER_MS } from "../internal/constants.js";
 import { detectCborBackend } from "../internal/cborBackend.js";
+import { escrowLockFloor } from "../internal/minAdaFloor.js";
 import type { LiveOgmiosProvider } from "../../chain/LiveOgmiosProvider.js";
 
 export interface PostEscrowParams {
@@ -129,7 +130,7 @@ export async function buildPostEscrowTx(
   // supplier-side validation in M1-C can verify role/content/system integrity.
   const promptHash = sha256Utf8Hex(canonicalize(messages));
 
-  const totalLocked =
+  const economicTotal =
     advertDatum.price_lovelace +
     advertDatum.buyer_bond_lovelace +
     advertDatum.supplier_bond_lovelace;
@@ -151,6 +152,11 @@ export async function buildPostEscrowTx(
     state: "Open",
   };
 
+  // Lock enough that the escrow output satisfies min-ada in its LARGEST
+  // future state (Submitted) - value_equal on Claim/Submit forbids any
+  // later bump (min-ada floor).
+  const totalLocked = escrowLockFloor(escrowDatum, economicTotal);
+
   // Live path: produce real Cardano CBOR via lucid-evolution.
   if (detectCborBackend(chain) === "live") {
     const liveCborPath = "../internal/liveCbor.js";

packages/shared/src/tx/escrow/postTtsEscrow.ts

@@ -31,6 +31,7 @@ import { loadBlueprint } from "../blueprint.js";
 import { encodeTxBody, sha256Hex } from "../internal/testTxBody.js";
 import { mockSlotToWallclockMs, NETWORK_BUFFER_MS } from "../internal/constants.js";
 import { detectCborBackend } from "../internal/cborBackend.js";
+import { escrowLockFloor } from "../internal/minAdaFloor.js";
 import type { LiveOgmiosProvider } from "../../chain/LiveOgmiosProvider.js";
 
 /** TTS request envelope. The buyer-side hash and the supplier-side hash
@@ -149,7 +150,7 @@ export async function buildPostTtsEscrowTx(
   const requestSpecHash = sha256Utf8Hex(requestSpecCanonical);
   const promptHash = ttsPromptHash(request);
 
-  const totalLocked =
+  const economicTotal =
     advertDatum.price_lovelace +
     advertDatum.buyer_bond_lovelace +
     advertDatum.supplier_bond_lovelace;
@@ -171,6 +172,11 @@ export async function buildPostTtsEscrowTx(
     state: "Open",
   };
 
+  // Lock enough that the escrow output satisfies min-ada in its LARGEST
+  // future state (Submitted) - value_equal on Claim/Submit forbids any
+  // later bump (min-ada floor).
+  const totalLocked = escrowLockFloor(escrowDatum, economicTotal);
+
   // Live path: reuse the chat builder. The live cbor path is already
   // capability-agnostic — `messages` is `void`-marked there. We pass an
   // empty array so the type checker is satisfied; the actual on-chain

packages/shared/src/tx/index.ts

@@ -2,8 +2,9 @@
  * tx/index.ts — public exports for M1-B tx builders.
  */
 
-export type { ChatMessage, WalletKey, BuildResult, PostAdvertBuildResult, PostEscrowBuildResult } from "./types.js";
+export type { ChatMessage, ToolCall, WalletKey, BuildResult, PostAdvertBuildResult, PostEscrowBuildResult } from "./types.js";
 export { TxConstructionError } from "./types.js";
+export { normalizeChatMessage, chatMessagesEquivalent, toolCallsEqual } from "./chatMessage.js";
 export { mockSlotToWallclockMs, mockWallclockMsToSlot, NETWORK_BUFFER_MS } from "./internal/constants.js";
 export { detectCborBackend, type CborBackend } from "./internal/cborBackend.js";
 export type { Signer } from "./signer.js";

packages/shared/src/tx/internal/liveCbor.ts

@@ -358,6 +358,45 @@ function rethrowAsTxError(err: unknown, fallback: string): never {
   throw new TxConstructionError(fallback, msg);
 }
 
+/** Choose PostEscrow inputs that PRESERVE a pure-ADA collateral UTxO for the
+ * later Accept/Reclaim script-spend. PostEscrow is NOT a script spend, so lucid
+ * is otherwise free to consume the dedicated ≥5-ADA collateral UTxO as an
+ * ordinary input — leaving the wallet with no collateral candidate and
+ * stranding the escrow when Accept later runs (the fragmentation bug observed
+ * on back-to-back requests).
+ *
+ * Reserve the SMALLEST pure-ADA UTxO ≥ collateral floor and fund the escrow
+ * from the remaining UTxOs. Returns null (→ default lucid coin selection) when
+ * reservation isn't possible or needed:
+ *   - a single UTxO (nothing to reserve),
+ *   - no qualifying pure-ADA collateral UTxO, or
+ *   - excluding it would underfund the escrow. The large-single-UTxO case is
+ *     safe under default selection anyway: the change output is itself a
+ *     pure-ADA UTxO well above the collateral floor. */
+export function reserveCollateralInputs(
+  utxos: LucidUTxO[],
+  lockedLovelace: bigint,
+): LucidUTxO[] | null {
+  if (utxos.length < 2) return null;
+  const candidates = utxos
+    .filter(
+      (u) =>
+        u.assets.lovelace >= COLLATERAL_MIN_LOVELACE &&
+        Object.keys(u.assets).every((k) => k === "lovelace"),
+    )
+    .sort((a, b) => (a.assets.lovelace < b.assets.lovelace ? -1 : 1));
+  if (candidates.length === 0) return null;
+  const reserved = candidates[0];
+  const remaining = utxos.filter(
+    (u) => !(u.txHash === reserved.txHash && u.outputIndex === reserved.outputIndex),
+  );
+  if (remaining.length === 0) return null;
+  const remainingLovelace = remaining.reduce((s, u) => s + u.assets.lovelace, 0n);
+  // Cover the locked output + tx fee + a min-change cushion; else fall back.
+  if (remainingLovelace < lockedLovelace + 2_000_000n) return null;
+  return remaining;
+}
+
 // ─── PostEscrow ──────────────────────────────────────────────────────
 
 export async function buildLiveTxForEscrow(
@@ -382,6 +421,12 @@ export async function buildLiveTxForEscrow(
 
   const lockedLovelace = totalLocked < MIN_UTXO_LOVELACE ? MIN_UTXO_LOVELACE : totalLocked;
 
+  // Preserve a pure-ADA collateral UTxO so the buyer's later Accept/Reclaim
+  // script-spend can find collateral. Without this, PostEscrow coin selection
+  // can consume the 5-ADA collateral UTxO and strand the escrow at Accept.
+  const walletUtxos = await lucid.wallet().getUtxos();
+  const reservedInputs = reserveCollateralInputs(walletUtxos, lockedLovelace);
+
   let signed;
   try {
     const txBuilder = lucid
@@ -404,7 +449,12 @@ export async function buildLiveTxForEscrow(
       // becomes change. Same fix as Claim/Submit/Accept paths.
       .setMinFee(500_000n);
 
-    const completed = await txBuilder.complete();
+    // When we can reserve collateral, restrict coin selection to the remaining
+    // (working) UTxOs so the collateral candidate survives for Accept. Else
+    // fall back to lucid's default selection (single/large-UTxO cases are safe).
+    const completed = reservedInputs
+      ? await txBuilder.complete({ presetWalletInputs: reservedInputs, localUPLCEval: false })
+      : await txBuilder.complete();
     signed = await completed.sign.withWallet().complete();
   } catch (err) {
     rethrowAsTxError(err, "post-escrow build failed");

packages/shared/src/tx/internal/minAdaFloor.ts

@@ -0,0 +1,67 @@
+/**
+ * minAdaFloor.ts — min-ada floor for the escrow's LARGEST future datum.
+ *
+ * The escrow validator requires value_equal(continuing, in) on Claim and
+ * Submit, so the lovelace locked at POST time must already satisfy min-ada
+ * for every datum the output will ever carry. The largest is the Submitted
+ * state: submitted_at None -> Some(POSIX ms) and result_receipt_hash
+ * None -> Some(32 bytes) add ~43 bytes over Open/Claimed. If the posted
+ * lovelace sits below that state's min-ada, lucid bumps the Submit
+ * continuing output to min-ada, value_equal fails, and the validator
+ * errors with no traces (the 2026-08-07 mainnet incident: the 33-byte
+ * "ocr.page.extract.chandra-ocr-2.v1" capability_id pushed the Submitted
+ * output 11,030 lovelace over a 2,200,000 lock; the 20-byte chat
+ * capability stayed 49,310 under, which is why only OCR Submits failed).
+ *
+ * escrowLockFloor() returns the lovelace to lock: the economic total
+ * (payment + both bonds), raised to the Submitted-state min-ada plus a
+ * safety margin when the total alone is too small.
+ */
+
+import type { EscrowDatum } from "../../cbor/types.js";
+import { encodeEscrowDatum } from "../../cbor/EscrowDatum.js";
+
+/** Conway/Babbage utxoCostPerByte on Vector mainnet (protocol params). */
+const UTXO_COST_PER_BYTE = 4310n;
+
+/** Ledger constant: min-ada = (160 + serialized output bytes) * costPerByte. */
+const OUTPUT_OVERHEAD_BYTES = 160n;
+
+/** Covers CBOR framing drift between this estimate and the ledger's exact
+ * serialization (address, coin width, datum wrapper). Generous on purpose:
+ * 50k lovelace = 0.05 AP3X, dwarfed by per-leg tx fees. */
+const SAFETY_MARGIN_LOVELACE = 50_000n;
+
+/** Serialized-output byte estimate for an enterprise script address output
+ * carrying `lovelace` and an inline datum of `datumBytes`. Mirrors the
+ * arithmetic validated against mainnet on 2026-08-07 (minada-calc). */
+function estimateOutputBytes(datumBytes: number, lovelace: bigint): bigint {
+  const addr = 1n + 29n;
+  const coin = 1n + (lovelace > 0xffffffffn ? 8n : 4n);
+  const datumField = 1n + 2n + 3n + BigInt(datumBytes);
+  const mapOverhead = 3n;
+  return addr + coin + datumField + mapOverhead;
+}
+
+/** Min-ada for the escrow output when it carries `datum`. */
+export function minAdaForEscrowDatum(datum: EscrowDatum, lovelace: bigint): bigint {
+  const datumBytes = encodeEscrowDatum(datum).length / 2;
+  const size = estimateOutputBytes(datumBytes, lovelace);
+  return (OUTPUT_OVERHEAD_BYTES + size) * UTXO_COST_PER_BYTE;
+}
+
+/** The lovelace a POST must lock so the escrow output satisfies min-ada in
+ * every reachable state, including Submitted. `economicTotal` is
+ * payment + buyer_bond + supplier_bond. */
+export function escrowLockFloor(openDatum: EscrowDatum, economicTotal: bigint): bigint {
+  const submittedShape: EscrowDatum = {
+    ...openDatum,
+    // Representative worst-case Submit fields: a 13-digit POSIX ms stamp
+    // and a 32-byte receipt hash — sizes, not values, matter here.
+    submitted_at: openDatum.deliver_by,
+    result_receipt_hash: "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
+    state: "Submitted",
+  };
+  const floor = minAdaForEscrowDatum(submittedShape, economicTotal) + SAFETY_MARGIN_LOVELACE;
+  return floor > economicTotal ? floor : economicTotal;
+}

packages/shared/src/tx/internal/reserveCollateral.test.ts

@@ -0,0 +1,42 @@
+import { describe, it, expect } from "vitest";
+import { reserveCollateralInputs } from "./liveCbor.js";
+
+// Minimal LucidUTxO-shaped fixtures (the helper only reads txHash/outputIndex/assets).
+const pure = (id: string, lovelace: bigint) =>
+  ({ txHash: id, outputIndex: 0, assets: { lovelace } }) as never;
+const mixed = (id: string, lovelace: bigint) =>
+  ({ txHash: id, outputIndex: 0, assets: { lovelace, "policy.tok": 1n } }) as never;
+
+const LOCKED = 2_200_000n; // price + buyer_bond + supplier_bond
+const ids = (r: ReturnType<typeof reserveCollateralInputs>) =>
+  (r ?? []).map((u: { txHash: string }) => u.txHash);
+
+describe("reserveCollateralInputs", () => {
+  it("reserves a 5-ADA collateral UTxO and funds from the rest", () => {
+    const r = reserveCollateralInputs([pure("collat", 5_000_000n), pure("work", 6_000_000n)], LOCKED);
+    expect(ids(r)).toEqual(["work"]); // collat (smallest ≥5) reserved
+  });
+
+  it("reserves the SMALLEST qualifying candidate", () => {
+    const r = reserveCollateralInputs([pure("big", 9_000_000n), pure("small", 5_000_000n)], LOCKED);
+    expect(ids(r)).toEqual(["big"]); // small reserved as collateral
+  });
+
+  it("only reserves PURE-ADA UTxOs (ignores ones carrying native assets)", () => {
+    const r = reserveCollateralInputs([mixed("mixed", 10_000_000n), pure("purecol", 6_000_000n)], LOCKED);
+    expect(ids(r)).toEqual(["mixed"]); // purecol reserved, fund from the mixed UTxO
+  });
+
+  it("returns null for a single UTxO (large change stays as collateral under default selection)", () => {
+    expect(reserveCollateralInputs([pure("only", 12_000_000n)], LOCKED)).toBeNull();
+  });
+
+  it("returns null when no UTxO qualifies as collateral", () => {
+    expect(reserveCollateralInputs([pure("a", 4_000_000n), pure("b", 4_000_000n)], LOCKED)).toBeNull();
+  });
+
+  it("returns null when reserving collateral would underfund the escrow", () => {
+    // {5 collateral, 3 working}: working can't cover locked + cushion → fall back.
+    expect(reserveCollateralInputs([pure("collat", 5_000_000n), pure("work", 3_000_000n)], LOCKED)).toBeNull();
+  });
+});

packages/shared/src/tx/server.ts

@@ -38,3 +38,10 @@ export type {
   ConsolidateWalletFlowResult,
 } from "./wallet/runConsolidateWallet.js";
 export { runConsolidateWallet } from "./wallet/runConsolidateWallet.js";
+
+// ── Wallet withdraw (custodial exit; live-only) ─────────────────────────
+export type {
+  WithdrawWalletParams,
+  WithdrawWalletBuildResult,
+} from "./wallet/withdrawWallet.js";
+export { buildWithdrawTx } from "./wallet/withdrawWallet.js";

packages/shared/src/tx/types.ts

@@ -11,14 +11,29 @@
 
 import type { OutputReference } from "../chain/ChainProvider.js";
 
+/**
+ * ToolCall — OpenAI-compatible function tool call emitted by an assistant turn.
+ * `function.arguments` is the raw JSON string as produced by the model.
+ */
+export interface ToolCall {
+  id: string;
+  type: "function";
+  function: { name: string; arguments: string };
+}
+
 /**
  * ChatMessage — OpenAI-compatible chat message.
- * v1 supports user/system/assistant roles. The wire shape is intentionally
- * narrow; future capabilities (tools, multimodal) will extend or replace it.
+ * `content` is always a string ("" for tool-call-only assistant messages —
+ * OpenAI's `content: null` is normalized on ingest). `tool_calls` /
+ * `tool_call_id` MUST be omitted (not set to undefined) when absent: the
+ * receipt hash canonicalizes the transcript objects, so field presence is
+ * part of the identity shared between supplier transcript and gateway mirror.
  */
 export interface ChatMessage {
-  role: "system" | "user" | "assistant";
+  role: "system" | "user" | "assistant" | "tool";
   content: string;
+  tool_calls?: ToolCall[];
+  tool_call_id?: string;
 }
 
 /**

packages/shared/src/tx/wallet/withdrawWallet.ts

@@ -0,0 +1,81 @@
+/**
+ * withdrawWallet.ts — custodial-exit tx builder (wallet → external address).
+ *
+ * Mirrors consolidateWallet.ts but pays a chosen amount to an arbitrary bech32
+ * address (lucid returns the change to the wallet). This is the withdrawal path
+ * for the gateway's custodial wallets: a user can move their unspent AP3X back
+ * out. No script, no datum, no native assets.
+ *
+ * `amountLovelace` omitted ⇒ withdraw all available minus a fee reserve.
+ * Live-only (needs a real Ogmios endpoint).
+ */
+
+import type { LiveOgmiosProvider } from "../../chain/LiveOgmiosProvider.js";
+import type { BuildResult, WalletKey } from "../types.js";
+import { TxConstructionError } from "../types.js";
+import { OgmiosLucidProvider } from "../../chain/OgmiosLucidProvider.js";
+import { createLucidContext } from "../internal/lucidContext.js";
+import { DEFAULT_FEE_RESERVE } from "./planConsolidate.js";
+
+export interface WithdrawWalletParams {
+  chain: LiveOgmiosProvider;
+  walletKey: WalletKey;
+  /** Destination bech32 address. */
+  toAddress: string;
+  /** Lovelace to send. Omit to withdraw all available minus the fee reserve. */
+  amountLovelace?: bigint;
+}
+
+export interface WithdrawWalletBuildResult extends BuildResult {
+  amountLovelace: bigint;
+  toAddress: string;
+}
+
+export async function buildWithdrawTx(
+  params: WithdrawWalletParams,
+): Promise<WithdrawWalletBuildResult> {
+  const { chain, walletKey, toAddress } = params;
+
+  const provider = new OgmiosLucidProvider({ ogmiosUrl: chain.url, fetch: chain.fetchImpl });
+  const { lucid } = await createLucidContext(
+    provider,
+    walletKey,
+    { networkId: 1, systemStartUnix: 0, slotLengthMs: 1000 },
+    { usePresetProtocolParameters: true },
+  );
+
+  const realWalletUtxos = await lucid.wallet().getUtxos();
+  const total = realWalletUtxos.reduce((sum, u) => sum + (u.assets.lovelace ?? 0n), 0n);
+  const spendable = total - DEFAULT_FEE_RESERVE;
+
+  const amount = params.amountLovelace ?? spendable;
+  if (amount <= 0n) {
+    throw new TxConstructionError("withdraw_amount_invalid", "nothing to withdraw");
+  }
+  if (amount > spendable) {
+    throw new TxConstructionError(
+      "withdraw_insufficient",
+      `requested ${amount} exceeds withdrawable ${spendable} (total ${total} minus fee reserve)`,
+    );
+  }
+
+  let signed;
+  try {
+    const txBuilder = lucid
+      .newTx()
+      .pay.ToAddress(toAddress, { lovelace: amount })
+      .addSignerKey(walletKey.pubKeyHash)
+      .setMinFee(500_000n);
+    const completed = await txBuilder.complete({ presetWalletInputs: realWalletUtxos, localUPLCEval: false });
+    signed = await completed.sign.withWallet().complete();
+  } catch (err) {
+    const msg = err instanceof Error ? err.message : String(err);
+    throw new TxConstructionError("withdraw_build_failed", msg);
+  }
+
+  const txCborHex = signed.toCBOR();
+  const expectedTxHash = signed.toHash();
+  await chain.submitTx(txCborHex);
+
+  return { txCborHex, expectedTxHash, amountLovelace: amount, toAddress };
+}

pnpm-lock.yaml

@@ -4,6 +4,11 @@ settings:
   autoInstallPeers: true
   excludeLinksFromLockfile: false
 
+patchedDependencies:
+  libsodium-wrappers-sumo@0.7.16:
+    hash: 761a204004f889b65fdf148159f4bd90733703d63a0ff00eb0671c92ea085096
+    path: patches/libsodium-wrappers-sumo@0.7.16.patch
+
 importers:
 
   .:
@@ -160,6 +165,46 @@ importers:
         specifier: ^5.4.0
         version: 5.4.21(@types/node@25.6.0)
 
+  gateway:
+    dependencies:
+      '@marketplace/buyer':
+        specifier: workspace:*
+        version: link:../buyer
+      '@marketplace/shared':
+        specifier: workspace:*
+        version: link:../packages/shared
+      '@noble/ed25519':
+        specifier: ^2.3.0
+        version: 2.3.0
+      '@noble/hashes':
+        specifier: ^1.8.0
+        version: 1.8.0
+      bech32:
+        specifier: ^2.0.0
+        version: 2.0.0
+      better-sqlite3:
+        specifier: ^11.9.1
+        version: 11.10.0
+      express:
+        specifier: ^4.21.2
+        version: 4.22.1
+    devDependencies:
+      '@types/better-sqlite3':
+        specifier: ^7.6.12
+        version: 7.6.13
+      '@types/express':
+        specifier: ^5.0.3
+        version: 5.0.6
+      supertest:
+        specifier: ^7.0.0
+        version: 7.2.2
+      tsx:
+        specifier: ^4.19.0
+        version: 4.21.0
+      typescript:
+        specifier: ^5.7.2
+        version: 5.9.3
+
   indexer:
     dependencies:
       '@marketplace/shared':
@@ -290,6 +335,16 @@ importers:
         specifier: ^5.7.2
         version: 5.9.3
 
+  wallet-monitor:
+    dependencies:
+      '@marketplace/shared':
+        specifier: workspace:*
+        version: link:../packages/shared
+    devDependencies:
+      typescript:
+        specifier: ^5.7.2
+        version: 5.9.3
+
 packages:
 
   '@adobe/css-tools@4.4.4':
@@ -3116,7 +3171,7 @@ snapshots:
       '@cardano-sdk/util': 0.16.0
       blake2b: 2.1.4
       i: 0.3.7
-      libsodium-wrappers-sumo: 0.7.16
+      libsodium-wrappers-sumo: 0.7.16(patch_hash=761a204004f889b65fdf148159f4bd90733703d63a0ff00eb0671c92ea085096)
       lodash: 4.18.1
       npm: 9.9.4
       pbkdf2: 3.1.5
@@ -4693,7 +4748,7 @@ snapshots:
 
   libsodium-sumo@0.7.16: {}
 
-  libsodium-wrappers-sumo@0.7.16:
+  libsodium-wrappers-sumo@0.7.16(patch_hash=761a204004f889b65fdf148159f4bd90733703d63a0ff00eb0671c92ea085096):
     dependencies:
       libsodium-sumo: 0.7.16