feat(builder): rate limit per identity instead of per process

The limiter was a module-level singleton, so one busy caller throttled every
other caller on the box and a shared daily budget was trivially exhausted.
Buckets are now keyed by authenticated identity, and keyed centrally so
reconnecting does not hand back a clean bucket.

packages/builder/src/vector/agent-network.ts

@@ -11,7 +11,7 @@ import {
 } from '@apexfusion/vector-mcp-shared/config';
 export { deriveNftAssetName };
 import { safetyLayer } from './safety.js';
-import { rateLimiter } from './rate-limiter.js';
+import { limiterFor } from './rate-limiter.js';
 
 // Registry constants - agent-registry v2 (audited, compliant)
 // Source blueprint: vector-ai-agents/agent-registry/deploy/agent-registry/plutus.json
@@ -156,19 +156,21 @@ async function getRegistryAddress() {
   return _registryAddress;
 }
 
-// ─── Rate limit wrapper ──────────────────────────────────────────────────────
-
-function checkRateLimit() {
-  const rateCheck = rateLimiter.check();
-  if (!rateCheck.allowed) {
-    return { content: [{ type: "text", text: `Rate limit exceeded. Retry after ${rateCheck.retryAfterMs}ms.` }] };
-  }
-  return null;
-}
-
 // ─── Tool Registration ───────────────────────────────────────────────────────
 
-export function registerAgentNetworkTools(server) {
+export function registerAgentNetworkTools(server, identity) {
+  const rateLimiter = limiterFor(identity);
+
+  // Rate limit wrapper - defined inside the register function (not at module
+  // scope) so this closes over the per-identity `rateLimiter` above rather
+  // than a module-wide global.
+  function checkRateLimit() {
+    const rateCheck = rateLimiter.check();
+    if (!rateCheck.allowed) {
+      return { content: [{ type: "text", text: `Rate limit exceeded. Retry after ${rateCheck.retryAfterMs}ms.` }] };
+    }
+    return null;
+  }
 
   // vector_get_agent_profile (read-only - no mnemonic needed)
   server.tool(

packages/builder/src/vector/rate-limiter.ts

@@ -24,4 +24,23 @@ export class RateLimiter {
 }
 
 const RATE_LIMIT_PER_MINUTE = parseInt(process.env.VECTOR_RATE_LIMIT_PER_MINUTE || '60');
-export const rateLimiter = new RateLimiter(RATE_LIMIT_PER_MINUTE);
+
+// One bucket per identity. A process-global limiter meant one busy caller
+// throttled everyone on the box; keying by identity fixes that. The registry
+// is keyed rather than per-connection so a caller cannot reset its own budget
+// by reconnecting.
+const limiters = new Map<string, RateLimiter>();
+
+export function limiterFor(identity: string): RateLimiter {
+  let limiter = limiters.get(identity);
+  if (!limiter) {
+    limiter = new RateLimiter(RATE_LIMIT_PER_MINUTE);
+    limiters.set(identity, limiter);
+  }
+  return limiter;
+}
+
+/** Test-only. Clears every bucket. */
+export function resetLimiters(): void {
+  limiters.clear();
+}

packages/builder/src/vector/self-improvement.ts

@@ -23,7 +23,7 @@ import {
   VECTOR_OGMIOS_URL, VECTOR_SUBMIT_URL, VECTOR_KOIOS_URL, VECTOR_EXPLORER_URL, explorerTxLink,
 } from '@apexfusion/vector-mcp-shared/config';
 import { safetyLayer } from './safety.js';
-import { rateLimiter } from './rate-limiter.js';
+import { limiterFor } from './rate-limiter.js';
 
 // Agent Registry policy ID (shared across all modules)
 const AGENT_REGISTRY_POLICY = process.env.AGENT_REGISTRY_POLICY || 'be1a0a2912da180757ed3cd61b56bb8eab0188c19dc3c0e3912d2c01';
@@ -85,14 +85,6 @@ function lovelaceToApex(lovelace: number | bigint): string {
   return (Number(BigInt(String(lovelace))) / 1_000_000).toFixed(6);
 }
 
-function checkRateLimit() {
-  const rateCheck = rateLimiter.check();
-  if (!rateCheck.allowed) {
-    return { content: [{ type: "text", text: `Rate limit exceeded. Retry after ${rateCheck.retryAfterMs}ms.` }] };
-  }
-  return null;
-}
-
 function scriptHashToAddress(hash: string): string {
   return credentialToAddress('Mainnet', { type: 'Script', hash });
 }
@@ -263,7 +255,20 @@ function parseEndorsementDatum(datumCbor: string): any | null {
 
 // ─── Tool Registration ──────────────────────────────────────────────────────
 
-export function registerSelfImprovementTools(server) {
+export function registerSelfImprovementTools(server, identity) {
+  const rateLimiter = limiterFor(identity);
+
+  // Rate limit wrapper - defined inside the register function (not at module
+  // scope, where it used to live alongside the other helpers above) so this
+  // closes over the per-identity `rateLimiter` above rather than a
+  // module-wide global.
+  function checkRateLimit() {
+    const rateCheck = rateLimiter.check();
+    if (!rateCheck.allowed) {
+      return { content: [{ type: "text", text: `Rate limit exceeded. Retry after ${rateCheck.retryAfterMs}ms.` }] };
+    }
+    return null;
+  }
 
   // ─── vector_self_improvement_browse (read-only) ───────────────────────────────
 

packages/builder/src/vector/vector.ts

@@ -13,7 +13,7 @@ import {
   VECTOR_OGMIOS_URL, VECTOR_SUBMIT_URL, VECTOR_KOIOS_URL, VECTOR_EXPLORER_URL, explorerTxLink,
 } from '@apexfusion/vector-mcp-shared/config';
 import { safetyLayer } from './safety.js';
-import { rateLimiter } from './rate-limiter.js';
+import { limiterFor } from './rate-limiter.js';
 import { registerAgentNetworkTools } from './agent-network.js';
 import { registerSelfImprovementTools } from './self-improvement.js';
 import type {
@@ -473,7 +473,8 @@ export async function interactWithContract(
 }
 
 // Register all Vector MCP tools
-export function registerVectorTools(server: McpServer) {
+export function registerVectorTools(server: McpServer, identity: string) {
+  const rateLimiter = limiterFor(identity);
 
   // vector_get_balance - Get balance for any address
   server.tool(
@@ -1286,8 +1287,8 @@ Funds ${actionVerb} the script address.
 
   // Agent network tools (register, discover, message, profile) live in agent-network.ts
   // to isolate C (Cardano WASM) imports from tsc's complex type inference
-  registerAgentNetworkTools(server);
+  registerAgentNetworkTools(server, identity);
 
   // Self-Improvement Module tools (Module 6)
-  registerSelfImprovementTools(server);
+  registerSelfImprovementTools(server, identity);
 }