diff --git a/desktop/src/app/routes/market.tsx b/desktop/src/app/routes/market.tsx
index 5d0dc6f053..f57aec45dc 100644
--- a/desktop/src/app/routes/market.tsx
+++ b/desktop/src/app/routes/market.tsx
@@ -8,11 +8,16 @@ import {
 import { ViewLoadingFallback } from "@/shared/ui/ViewLoadingFallback";
 
 type MarketRouteSearch = {
+  market?: string;
   scenario?: MarketScenarioId;
 };
 
 export const Route = createFileRoute("/market")({
   validateSearch: (search: Record<string, unknown>): MarketRouteSearch => ({
+    market:
+      typeof search.market === "string" && search.market.length <= 120
+        ? search.market
+        : undefined,
     scenario: isMarketScenarioId(search.scenario) ? search.scenario : undefined,
   }),
   component: MarketRouteComponent,
@@ -29,7 +34,10 @@ function MarketRouteComponent() {
     <React.Suspense
       fallback={<ViewLoadingFallback includeHeader kind="channel" />}
     >
-      <MarketScreen scenarioId={search.scenario ?? "finite"} />
+      <MarketScreen
+        marketId={search.market}
+        scenarioId={search.scenario ?? "finite"}
+      />
     </React.Suspense>
   );
 }
diff --git a/desktop/src/features/market/lib/marketProtocol.test.mjs b/desktop/src/features/market/lib/marketProtocol.test.mjs
new file mode 100644
index 0000000000..60e837bdfe
--- /dev/null
+++ b/desktop/src/features/market/lib/marketProtocol.test.mjs
@@ -0,0 +1,189 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import {
+  MARKET_PROTOCOL,
+  parseMarketEnvelope,
+  projectMarketNotes,
+} from "./marketProtocol.ts";
+
+const SELLER = "a".repeat(64);
+const BUYER = "b".repeat(64);
+const LISTING_ID = "1".repeat(64);
+const RESPONSE_ID = "2".repeat(64);
+const AWARD_ID = "3".repeat(64);
+const FULFILLMENT_ID = "4".repeat(64);
+
+function note(id, pubkey, createdAt, envelope) {
+  return { id, pubkey, createdAt, content: JSON.stringify(envelope), tags: [] };
+}
+
+function listing(overrides = {}) {
+  return {
+    protocol: MARKET_PROTOCOL,
+    type: "listing",
+    marketId: "incident-report",
+    version: 1,
+    listing: {
+      actorName: "Seller Agent",
+      direction: "offer",
+      mechanism: "fixed",
+      title: "Incident report",
+      summary: "A cited report delivered after award.",
+      quantity: 1,
+      priceSats: 50,
+      deliveryMinutes: 120,
+      ...overrides,
+    },
+  };
+}
+
+test("parseMarketEnvelope accepts v0 and rejects unrelated Pulse notes", () => {
+  assert.equal(parseMarketEnvelope("hello Pulse"), null);
+  assert.equal(parseMarketEnvelope('{"protocol":"other"}'), null);
+  assert.equal(parseMarketEnvelope(JSON.stringify(listing()))?.type, "listing");
+});
+
+test("projectMarketNotes folds offer through fake settlement", () => {
+  const notes = [
+    note(LISTING_ID, SELLER, 100, listing()),
+    note(RESPONSE_ID, BUYER, 101, {
+      protocol: MARKET_PROTOCOL,
+      type: "response",
+      marketId: "incident-report",
+      listingEventId: LISTING_ID,
+      actorName: "Buyer Agent",
+      quantity: 1,
+      amountSats: 50,
+      message: "I reserve the report.",
+    }),
+    note(AWARD_ID, SELLER, 102, {
+      protocol: MARKET_PROTOCOL,
+      type: "award",
+      marketId: "incident-report",
+      listingEventId: LISTING_ID,
+      responseEventId: RESPONSE_ID,
+      actorName: "Seller Agent",
+      quantity: 1,
+      amountSats: 50,
+    }),
+    note(FULFILLMENT_ID, SELLER, 103, {
+      protocol: MARKET_PROTOCOL,
+      type: "fulfillment",
+      marketId: "incident-report",
+      listingEventId: LISTING_ID,
+      awardEventId: AWARD_ID,
+      actorName: "Seller Agent",
+      message: "Report delivered with cited evidence.",
+    }),
+    note("5".repeat(64), BUYER, 104, {
+      protocol: MARKET_PROTOCOL,
+      type: "settlement",
+      marketId: "incident-report",
+      listingEventId: LISTING_ID,
+      awardEventId: AWARD_ID,
+      fulfillmentEventId: FULFILLMENT_ID,
+      actorName: "Buyer Agent",
+      amountSats: 50,
+    }),
+  ];
+
+  const projection = projectMarketNotes(notes);
+  assert.ok(projection);
+  assert.equal(projection.scenario.status, "Fulfilled");
+  assert.equal(projection.scenario.title, "Incident report");
+  assert.equal(projection.scenario.activity.length, 5);
+  assert.equal(
+    projection.scenario.activity[0].title,
+    "Sandbox settlement complete",
+  );
+  assert.deepEqual(projection.rejected, []);
+});
+
+test("projectMarketNotes selects an explicit market", () => {
+  const other = listing();
+  other.marketId = "other-market";
+  other.listing.title = "Other listing";
+  const projection = projectMarketNotes(
+    [
+      note(LISTING_ID, SELLER, 100, listing()),
+      note("9".repeat(64), BUYER, 99, other),
+    ],
+    "incident-report",
+  );
+  assert.ok(projection);
+  assert.equal(projection.scenario.title, "Incident report");
+});
+
+test("projectMarketNotes rejects overselling and unauthorized awards", () => {
+  const notes = [
+    note(LISTING_ID, SELLER, 100, listing()),
+    note(RESPONSE_ID, BUYER, 101, {
+      protocol: MARKET_PROTOCOL,
+      type: "response",
+      marketId: "incident-report",
+      listingEventId: LISTING_ID,
+      actorName: "Buyer Agent",
+      quantity: 1,
+      amountSats: 50,
+      message: "Reserve one.",
+    }),
+    note(AWARD_ID, BUYER, 102, {
+      protocol: MARKET_PROTOCOL,
+      type: "award",
+      marketId: "incident-report",
+      listingEventId: LISTING_ID,
+      responseEventId: RESPONSE_ID,
+      actorName: "Buyer Agent",
+      quantity: 1,
+      amountSats: 50,
+    }),
+  ];
+
+  const projection = projectMarketNotes(notes);
+  assert.ok(projection);
+  assert.equal(projection.scenario.status, "Open");
+  assert.equal(projection.rejected[0].reason, "only listing author may award");
+});
+
+test("reverse auction enforces the minimum decrement", () => {
+  const auction = listing({
+    direction: "request",
+    mechanism: "reverse-auction",
+    quantity: 1,
+    priceSats: undefined,
+    maxBudgetSats: 100,
+    minimumDecrementSats: 10,
+  });
+  const notes = [
+    note(LISTING_ID, SELLER, 100, auction),
+    note(RESPONSE_ID, BUYER, 101, {
+      protocol: MARKET_PROTOCOL,
+      type: "response",
+      marketId: "incident-report",
+      listingEventId: LISTING_ID,
+      actorName: "Bidder One",
+      quantity: 1,
+      amountSats: 90,
+      message: "I bid 90.",
+    }),
+    note("6".repeat(64), "c".repeat(64), 102, {
+      protocol: MARKET_PROTOCOL,
+      type: "response",
+      marketId: "incident-report",
+      listingEventId: LISTING_ID,
+      actorName: "Bidder Two",
+      quantity: 1,
+      amountSats: 85,
+      message: "I bid 85.",
+    }),
+  ];
+
+  const projection = projectMarketNotes(notes);
+  assert.ok(projection);
+  assert.equal(projection.scenario.liveMetrics[1].value, "1");
+  assert.equal(
+    projection.rejected[0].reason,
+    "bid does not meet minimum decrement",
+  );
+});
diff --git a/desktop/src/features/market/lib/marketProtocol.ts b/desktop/src/features/market/lib/marketProtocol.ts
new file mode 100644
index 0000000000..aafa057024
--- /dev/null
+++ b/desktop/src/features/market/lib/marketProtocol.ts
@@ -0,0 +1,511 @@
+import { z } from "zod";
+
+import type {
+  MarketActivity,
+  MarketScenario,
+  MarketScenarioId,
+} from "@/features/market/lib/marketPrototypeData";
+import type { UserNote } from "@/shared/api/socialTypes";
+import { truncatePubkey } from "@/shared/lib/pubkey";
+
+export const MARKET_PROTOCOL = "buzz-market/v0" as const;
+
+const EventId = z.string().regex(/^[0-9a-f]{64}$/);
+const MarketId = z.string().min(1).max(120);
+const ActorName = z.string().min(1).max(80);
+const PositiveInteger = z.number().int().positive();
+const NonnegativeInteger = z.number().int().nonnegative();
+
+const BaseEnvelope = z.object({
+  protocol: z.literal(MARKET_PROTOCOL),
+  marketId: MarketId,
+});
+
+const ListingEnvelope = BaseEnvelope.extend({
+  type: z.literal("listing"),
+  version: z.literal(1),
+  listing: z.object({
+    actorName: ActorName,
+    direction: z.enum(["offer", "request"]),
+    mechanism: z.enum(["fixed", "reverse-auction", "tender"]),
+    title: z.string().min(1).max(160),
+    summary: z.string().min(1).max(2_000),
+    quantity: z.union([PositiveInteger, z.literal("unlimited")]),
+    priceSats: PositiveInteger.optional(),
+    maxBudgetSats: PositiveInteger.optional(),
+    closesAt: NonnegativeInteger.optional(),
+    deliveryMinutes: PositiveInteger.optional(),
+    minimumDecrementSats: PositiveInteger.optional(),
+  }),
+});
+
+const ResponseEnvelope = BaseEnvelope.extend({
+  type: z.literal("response"),
+  listingEventId: EventId,
+  actorName: ActorName,
+  quantity: PositiveInteger,
+  amountSats: PositiveInteger.optional(),
+  message: z.string().min(1).max(2_000),
+});
+
+const AwardEnvelope = BaseEnvelope.extend({
+  type: z.literal("award"),
+  listingEventId: EventId,
+  responseEventId: EventId,
+  actorName: ActorName,
+  quantity: PositiveInteger,
+  amountSats: PositiveInteger,
+});
+
+const FulfillmentEnvelope = BaseEnvelope.extend({
+  type: z.literal("fulfillment"),
+  listingEventId: EventId,
+  awardEventId: EventId,
+  actorName: ActorName,
+  message: z.string().min(1).max(2_000),
+});
+
+const SettlementEnvelope = BaseEnvelope.extend({
+  type: z.literal("settlement"),
+  listingEventId: EventId,
+  awardEventId: EventId,
+  fulfillmentEventId: EventId,
+  actorName: ActorName,
+  amountSats: PositiveInteger,
+});
+
+export const MarketEnvelopeSchema = z.discriminatedUnion("type", [
+  ListingEnvelope,
+  ResponseEnvelope,
+  AwardEnvelope,
+  FulfillmentEnvelope,
+  SettlementEnvelope,
+]);
+
+export type MarketEnvelope = z.infer<typeof MarketEnvelopeSchema>;
+export type MarketListingEnvelope = z.infer<typeof ListingEnvelope>;
+
+export type MarketProjection = {
+  listingEventId: string;
+  scenario: MarketScenario;
+  rejected: Array<{ eventId: string; reason: string }>;
+};
+
+export function parseMarketEnvelope(content: string): MarketEnvelope | null {
+  let value: unknown;
+  try {
+    value = JSON.parse(content);
+  } catch {
+    return null;
+  }
+  const parsed = MarketEnvelopeSchema.safeParse(value);
+  return parsed.success ? parsed.data : null;
+}
+
+function scenarioIdForListing(
+  listing: MarketListingEnvelope["listing"],
+  settled: boolean,
+): MarketScenarioId {
+  if (settled) return "awarded";
+  if (listing.mechanism === "reverse-auction") return "auction";
+  if (listing.mechanism === "tender") return "tender";
+  return listing.quantity === "unlimited" ? "unlimited" : "finite";
+}
+
+function formatAt(timestamp: number): string {
+  return new Intl.DateTimeFormat("en-GB", {
+    hour: "2-digit",
+    minute: "2-digit",
+    timeZone: "UTC",
+    timeZoneName: "short",
+  }).format(new Date(timestamp * 1_000));
+}
+
+function actorDetail(pubkey: string): string {
+  return `agent · ${truncatePubkey(pubkey)}`;
+}
+
+function listingPrice(listing: MarketListingEnvelope["listing"]): string {
+  if (listing.mechanism === "fixed") {
+    return `${listing.priceSats ?? 0} sats per unit`;
+  }
+  if (listing.mechanism === "reverse-auction") {
+    return `Maximum ${listing.maxBudgetSats ?? 0} sats`;
+  }
+  return listing.maxBudgetSats
+    ? `Budget up to ${listing.maxBudgetSats} sats`
+    : "Judged on published criteria";
+}
+
+function validateListing(
+  listing: MarketListingEnvelope["listing"],
+): string | null {
+  if (listing.mechanism === "fixed" && !listing.priceSats) {
+    return "fixed listing requires priceSats";
+  }
+  if (listing.mechanism === "reverse-auction" && !listing.maxBudgetSats) {
+    return "reverse auction requires maxBudgetSats";
+  }
+  return null;
+}
+
+function responseIsValid(
+  listing: MarketListingEnvelope["listing"],
+  response: Extract<MarketEnvelope, { type: "response" }>,
+  bestAuctionBid: number | null,
+): string | null {
+  if (
+    listing.quantity !== "unlimited" &&
+    response.quantity > listing.quantity
+  ) {
+    return "response quantity exceeds listing quantity";
+  }
+  if (
+    listing.mechanism === "fixed" &&
+    response.amountSats !== listing.priceSats
+  ) {
+    return "fixed-price response must match priceSats";
+  }
+  if (listing.mechanism === "reverse-auction") {
+    if (!response.amountSats)
+      return "reverse-auction response requires amountSats";
+    if (listing.maxBudgetSats && response.amountSats > listing.maxBudgetSats) {
+      return "bid exceeds maximum budget";
+    }
+    const decrement = listing.minimumDecrementSats ?? 1;
+    if (
+      bestAuctionBid !== null &&
+      response.amountSats > bestAuctionBid - decrement
+    ) {
+      return "bid does not meet minimum decrement";
+    }
+  }
+  return null;
+}
+
+function envelopePhase(envelope: MarketEnvelope): number {
+  switch (envelope.type) {
+    case "listing":
+      return 0;
+    case "response":
+      return 1;
+    case "award":
+      return 2;
+    case "fulfillment":
+      return 3;
+    case "settlement":
+      return 4;
+  }
+}
+
+export function projectMarketNotes(
+  notes: UserNote[],
+  marketId?: string,
+): MarketProjection | null {
+  const parsed = notes
+    .map((note) => ({ note, envelope: parseMarketEnvelope(note.content) }))
+    .filter(
+      (entry): entry is { note: UserNote; envelope: MarketEnvelope } =>
+        entry.envelope !== null &&
+        (marketId === undefined || entry.envelope.marketId === marketId),
+    )
+    .sort(
+      (left, right) =>
+        left.note.createdAt - right.note.createdAt ||
+        envelopePhase(left.envelope) - envelopePhase(right.envelope) ||
+        left.note.id.localeCompare(right.note.id),
+    );
+  const listingEntry = parsed.find(
+    (entry) =>
+      entry.envelope.type === "listing" &&
+      validateListing(entry.envelope.listing) === null,
+  );
+  if (listingEntry?.envelope.type !== "listing") return null;
+
+  const listingEventId = listingEntry.note.id;
+  const listing = listingEntry.envelope;
+  const marketEvents = parsed.filter(
+    (entry) =>
+      entry.envelope.marketId === listing.marketId &&
+      entry.note.createdAt >= listingEntry.note.createdAt,
+  );
+  const responses = new Map<
+    string,
+    { note: UserNote; envelope: Extract<MarketEnvelope, { type: "response" }> }
+  >();
+  const awards = new Map<
+    string,
+    { note: UserNote; envelope: Extract<MarketEnvelope, { type: "award" }> }
+  >();
+  const fulfillments = new Map<
+    string,
+    {
+      note: UserNote;
+      envelope: Extract<MarketEnvelope, { type: "fulfillment" }>;
+    }
+  >();
+  const settlements = new Map<string, UserNote>();
+  const rejected: MarketProjection["rejected"] = [];
+  let awardedQuantity = 0;
+  let bestAuctionBid: number | null = null;
+
+  for (const entry of marketEvents) {
+    const { envelope, note } = entry;
+    if (envelope.type === "listing") continue;
+    if (envelope.listingEventId !== listingEventId) {
+      rejected.push({
+        eventId: note.id,
+        reason: "listingEventId does not target current listing",
+      });
+      continue;
+    }
+    if (listing.listing.closesAt && note.createdAt > listing.listing.closesAt) {
+      rejected.push({
+        eventId: note.id,
+        reason: "event arrived after listing close",
+      });
+      continue;
+    }
+
+    if (envelope.type === "response") {
+      const reason = responseIsValid(listing.listing, envelope, bestAuctionBid);
+      if (reason) {
+        rejected.push({ eventId: note.id, reason });
+        continue;
+      }
+      responses.set(note.id, { note, envelope });
+      if (listing.listing.mechanism === "reverse-auction") {
+        bestAuctionBid = envelope.amountSats ?? bestAuctionBid;
+      }
+      continue;
+    }
+
+    if (envelope.type === "award") {
+      const response = responses.get(envelope.responseEventId);
+      const available =
+        listing.listing.quantity === "unlimited"
+          ? Number.POSITIVE_INFINITY
+          : listing.listing.quantity - awardedQuantity;
+      const reason =
+        note.pubkey !== listingEntry.note.pubkey
+          ? "only listing author may award"
+          : !response
+            ? "award references unknown response"
+            : awards.has(envelope.responseEventId)
+              ? "response already awarded"
+              : envelope.quantity > response.envelope.quantity
+                ? "award quantity exceeds response quantity"
+                : envelope.quantity > available
+                  ? "award quantity exceeds available quantity"
+                  : listing.listing.mechanism !== "tender" &&
+                      envelope.amountSats !== response.envelope.amountSats
+                    ? "award amount differs from response"
+                    : null;
+      if (reason) {
+        rejected.push({ eventId: note.id, reason });
+        continue;
+      }
+      awards.set(envelope.responseEventId, { note, envelope });
+      awardedQuantity += envelope.quantity;
+      continue;
+    }
+
+    if (envelope.type === "fulfillment") {
+      const award = [...awards.values()].find(
+        (value) => value.note.id === envelope.awardEventId,
+      );
+      const response = award
+        ? responses.get(award.envelope.responseEventId)
+        : null;
+      const fulfiller =
+        listing.listing.direction === "offer"
+          ? listingEntry.note.pubkey
+          : response?.note.pubkey;
+      const reason = !award
+        ? "fulfillment references unknown award"
+        : note.pubkey !== fulfiller
+          ? "fulfillment author is not the delivering agent"
+          : fulfillments.has(envelope.awardEventId)
+            ? "award already fulfilled"
+            : null;
+      if (reason) {
+        rejected.push({ eventId: note.id, reason });
+        continue;
+      }
+      fulfillments.set(envelope.awardEventId, { note, envelope });
+      continue;
+    }
+
+    const award = [...awards.values()].find(
+      (value) => value.note.id === envelope.awardEventId,
+    );
+    const response = award
+      ? responses.get(award.envelope.responseEventId)
+      : null;
+    const fulfillment = fulfillments.get(envelope.awardEventId);
+    const payer =
+      listing.listing.direction === "offer"
+        ? response?.note.pubkey
+        : listingEntry.note.pubkey;
+    const reason =
+      !award || !fulfillment
+        ? "settlement requires a fulfilled award"
+        : envelope.fulfillmentEventId !== fulfillment.note.id
+          ? "settlement references wrong fulfillment"
+          : note.pubkey !== payer
+            ? "settlement author is not the payer"
+            : envelope.amountSats !==
+                award.envelope.amountSats * award.envelope.quantity
+              ? "settlement amount differs from award total"
+              : settlements.has(envelope.awardEventId)
+                ? "award already settled"
+                : null;
+    if (reason) {
+      rejected.push({ eventId: note.id, reason });
+      continue;
+    }
+    settlements.set(envelope.awardEventId, note);
+  }
+
+  const accepted = marketEvents.filter((entry) => {
+    if (entry.envelope.type === "listing")
+      return entry.note.id === listingEventId;
+    return !rejected.some((item) => item.eventId === entry.note.id);
+  });
+  const activities: MarketActivity[] = accepted
+    .map(({ note, envelope }): MarketActivity => {
+      if (envelope.type === "listing") {
+        return {
+          actor: envelope.listing.actorName,
+          at: formatAt(note.createdAt),
+          detail: `Contract v${envelope.version} is signed and open on Pulse.`,
+          state: "accepted",
+          title: "Market opened",
+        };
+      }
+      if (envelope.type === "response") {
+        return {
+          actor: envelope.actorName,
+          at: formatAt(note.createdAt),
+          detail: envelope.message,
+          state: "discussion",
+          title:
+            listing.listing.mechanism === "reverse-auction"
+              ? "Bid submitted"
+              : "Response submitted",
+        };
+      }
+      if (envelope.type === "award") {
+        return {
+          actor: envelope.actorName,
+          at: formatAt(note.createdAt),
+          detail: `Awarded ${envelope.quantity} unit for ${envelope.amountSats} sats each.`,
+          state: "terminal",
+          title: "Response awarded",
+        };
+      }
+      if (envelope.type === "fulfillment") {
+        return {
+          actor: envelope.actorName,
+          at: formatAt(note.createdAt),
+          detail: envelope.message,
+          state: "terminal",
+          title: "Delivery fulfilled",
+        };
+      }
+      return {
+        actor: envelope.actorName,
+        at: formatAt(note.createdAt),
+        detail: `${envelope.amountSats} fake sats released for the fulfilled award.`,
+        state: "terminal",
+        title: "Sandbox settlement complete",
+      };
+    })
+    .reverse();
+
+  const settled = settlements.size > 0;
+  const fulfilled = fulfillments.size;
+  const scenarioId = scenarioIdForListing(listing.listing, settled);
+  const quantity = listing.listing.quantity;
+  const available =
+    quantity === "unlimited"
+      ? "Unlimited"
+      : `${quantity - awardedQuantity} of ${quantity}`;
+  const directionLabel =
+    listing.listing.direction === "offer" ? "Seller" : "Requester";
+  const closeAt = listing.listing.closesAt
+    ? `Closes ${new Date(listing.listing.closesAt * 1_000).toISOString().replace("T", " ").slice(0, 16)} UTC`
+    : quantity === "unlimited"
+      ? "No quantity limit"
+      : "No scheduled close · UTC";
+  const status: MarketScenario["status"] = settled
+    ? "Fulfilled"
+    : awards.size > 0
+      ? "Awarded"
+      : "Open";
+
+  return {
+    listingEventId,
+    rejected,
+    scenario: {
+      id: scenarioId,
+      eyebrow: `${listing.listing.direction === "offer" ? "Offer" : "Request"} · ${listing.listing.mechanism.replace("-", " ")} · ${quantity === "unlimited" ? "unlimited" : "finite"}`,
+      title: listing.listing.title,
+      summary: listing.listing.summary,
+      direction:
+        listing.listing.direction === "offer"
+          ? `Buyer pays ${listingPrice(listing.listing)} · Seller delivers`
+          : `Requester pays ${listingPrice(listing.listing)} · Winning agent delivers`,
+      mode:
+        listing.listing.mechanism === "fixed"
+          ? "Fixed price"
+          : listing.listing.mechanism === "reverse-auction"
+            ? "Reverse auction"
+            : "Qualitative tender",
+      status,
+      statusDetail: `Pulse state ${accepted.at(-1)?.note.id.slice(0, 8) ?? listingEventId.slice(0, 8)} · ${formatAt(accepted.at(-1)?.note.createdAt ?? listingEntry.note.createdAt)}`,
+      closeAt,
+      contractId: `${MARKET_PROTOCOL}:${listing.marketId}:v${listing.version}`,
+      primaryAction:
+        listing.listing.mechanism === "reverse-auction"
+          ? `Bid below ${bestAuctionBid ?? listing.listing.maxBudgetSats ?? 0} sats`
+          : `Respond for ${listing.listing.priceSats ?? listing.listing.maxBudgetSats ?? 0} sats`,
+      terms: [
+        {
+          label: directionLabel,
+          value: listing.listing.actorName,
+          detail: actorDetail(listingEntry.note.pubkey),
+        },
+        {
+          label: listing.listing.direction === "offer" ? "Price" : "Reward",
+          value: listingPrice(listing.listing),
+          detail: "fake-sats sandbox",
+        },
+        { label: "Initial quantity", value: String(quantity) },
+        ...(listing.listing.deliveryMinutes
+          ? [
+              {
+                label: "Delivery deadline",
+                value: `${listing.listing.deliveryMinutes} minutes after award`,
+              },
+            ]
+          : []),
+        {
+          label: "Contract version",
+          value: `v${listing.version} · event ${listingEventId.slice(0, 8)}`,
+        },
+        { label: "Settlement", value: "Signed fake-sats receipt" },
+      ],
+      liveMetrics: [
+        { label: "Available", value: available },
+        { label: "Responses", value: String(responses.size) },
+        { label: "Awarded", value: String(awards.size) },
+        {
+          label: "Fulfilled / settled",
+          value: `${fulfilled} / ${settlements.size}`,
+        },
+      ],
+      activity: activities,
+    },
+  };
+}
diff --git a/desktop/src/features/market/lib/useLiveMarketScenario.ts b/desktop/src/features/market/lib/useLiveMarketScenario.ts
new file mode 100644
index 0000000000..5cd2938d9d
--- /dev/null
+++ b/desktop/src/features/market/lib/useLiveMarketScenario.ts
@@ -0,0 +1,35 @@
+import { useQuery } from "@tanstack/react-query";
+import * as React from "react";
+
+import { projectMarketNotes } from "@/features/market/lib/marketProtocol";
+import type { MarketScenario } from "@/features/market/lib/marketPrototypeData";
+import { getGlobalNotes } from "@/shared/api/social";
+import { useFocusedRefetchInterval } from "@/shared/lib/useDocumentVisible";
+
+const MARKET_REFETCH_INTERVAL_MS = 5_000;
+
+export function useLiveMarketScenario(
+  fallback: MarketScenario,
+  marketId?: string,
+): {
+  scenario: MarketScenario;
+  live: boolean;
+  isLoading: boolean;
+} {
+  const refetchInterval = useFocusedRefetchInterval(MARKET_REFETCH_INTERVAL_MS);
+  const query = useQuery({
+    queryKey: ["market-notes", marketId ?? "latest"],
+    queryFn: () => getGlobalNotes({ limit: 200 }),
+    refetchInterval,
+    refetchOnWindowFocus: true,
+  });
+  const projection = React.useMemo(
+    () => projectMarketNotes(query.data?.notes ?? [], marketId),
+    [marketId, query.data?.notes],
+  );
+  return {
+    scenario: projection?.scenario ?? fallback,
+    live: projection !== null,
+    isLoading: query.isLoading,
+  };
+}
diff --git a/desktop/src/features/market/ui/MarketScreen.tsx b/desktop/src/features/market/ui/MarketScreen.tsx
index 188617d0c6..102d61f834 100644
--- a/desktop/src/features/market/ui/MarketScreen.tsx
+++ b/desktop/src/features/market/ui/MarketScreen.tsx
@@ -10,6 +10,7 @@ import * as React from "react";
 
 import { ChatHeader } from "@/features/chat/ui/ChatHeader";
 import { AgentWalletPanel } from "@/features/market/ui/AgentWalletPanel";
+import { useLiveMarketScenario } from "@/features/market/lib/useLiveMarketScenario";
 import {
   MARKET_SCENARIOS,
   type MarketActivity,
@@ -74,8 +75,18 @@ const ACTIVITY_STYLE: Record<
   },
 };
 
-export function MarketScreen({ scenarioId }: { scenarioId: MarketScenarioId }) {
-  const scenario = MARKET_SCENARIOS[scenarioId];
+export function MarketScreen({
+  marketId,
+  scenarioId,
+}: {
+  marketId?: string;
+  scenarioId: MarketScenarioId;
+}) {
+  const fallbackScenario = MARKET_SCENARIOS[scenarioId];
+  const { scenario, live, isLoading } = useLiveMarketScenario(
+    fallbackScenario,
+    marketId,
+  );
   const sidebar = useOptionalSidebar();
   const [createOpen, setCreateOpen] = React.useState(false);
   const [walletOpen, setWalletOpen] = React.useState(true);
@@ -139,7 +150,11 @@ export function MarketScreen({ scenarioId }: { scenarioId: MarketScenarioId }) {
                   </p>
                 </div>
                 <Badge variant="secondary">
-                  {scenario.activity.length} messages
+                  {isLoading
+                    ? "Checking Pulse…"
+                    : live
+                      ? "Live · Pulse"
+                      : `${scenario.activity.length} messages`}
                 </Badge>
               </div>
               <div>
diff --git a/docs/market-sandbox-v0.md b/docs/market-sandbox-v0.md
new file mode 100644
index 0000000000..9038cce0fb
--- /dev/null
+++ b/docs/market-sandbox-v0.md
@@ -0,0 +1,35 @@
+# Buzz Market v0 sandbox protocol
+
+`buzz-market/v0` is a disposable integration protocol for proving a two-agent
+market over today's relay. Each event is a signed NIP-01 kind `1` Pulse note
+whose entire content is one compact JSON object. Pulse provides discovery; the
+note ID and author key provide immutable references and identity.
+
+## Lifecycle
+
+1. `listing`: seller/requester publishes fixed, reverse-auction, or tender terms.
+2. `response`: another agent orders, bids, or proposes against the exact listing event ID.
+3. `award`: listing author selects a response and quantity.
+4. `fulfillment`: the delivering agent references the award.
+5. `settlement`: the payer releases fake sats after fulfillment.
+
+All lifecycle events repeat `marketId` for filtering and carry
+`listingEventId`; dependent transitions also reference the exact preceding
+event. Quantities and sats are positive integers. Timestamps are Nostr event
+timestamps, always UTC.
+
+The desktop projector deterministically sorts `(created_at, lifecycle phase,
+id)`, validates references and signer roles, prevents duplicate awards and
+settlements, and prevents accepted awards from exceeding finite quantity.
+Reverse auctions
+enforce the declared budget and minimum decrement. Invalid notes remain signed
+history but do not mutate projected state.
+
+This is not settlement or escrow. Fake sats are receipt fields only. Relay-side
+atomicity, authoritative agent-only writes, canonical market kinds, and wallet
+spend controls remain required before production.
+
+## Commands
+
+Use `scripts/market-sandbox.sh --help`. Each identity sets its own
+`BUZZ_PRIVATE_KEY`; both use the same `BUZZ_RELAY_URL`.
diff --git a/scripts/market-sandbox.sh b/scripts/market-sandbox.sh
new file mode 100755
index 0000000000..62d1c54a2b
--- /dev/null
+++ b/scripts/market-sandbox.sh
@@ -0,0 +1,111 @@
+#!/usr/bin/env bash
+# Relay-backed two-agent sandbox for buzz-market/v0 kind:1 Pulse envelopes.
+set -euo pipefail
+
+usage() {
+  cat <<'TXT'
+Usage:
+  market-sandbox.sh listing --market ID --actor NAME --title TEXT --summary TEXT [--direction offer|request] [--mechanism fixed|reverse-auction|tender] [--quantity N|unlimited] [--price N] [--budget N] [--decrement N] [--delivery-minutes N] [--closes-at UNIX]
+  market-sandbox.sh response --market ID --listing EVENT --actor NAME --quantity N [--amount N] --message TEXT
+  market-sandbox.sh award --market ID --listing EVENT --response EVENT --actor NAME --quantity N --amount N
+  market-sandbox.sh fulfill --market ID --listing EVENT --award EVENT --actor NAME --message TEXT
+  market-sandbox.sh settle --market ID --listing EVENT --award EVENT --fulfillment EVENT --actor NAME --amount N
+  market-sandbox.sh watch --pubkey HEX [--pubkey HEX ...]
+
+BUZZ_RELAY_URL and BUZZ_PRIVATE_KEY select the relay and signing agent. Writes
+publish strict buzz-market/v0 JSON as ordinary kind:1 Pulse notes.
+TXT
+}
+
+die() { echo "market-sandbox: $*" >&2; exit 1; }
+need() { [[ -n "${2:-}" ]] || die "missing --$1"; }
+json_write() {
+  local payload="$1"
+  buzz social publish --content "$payload"
+}
+
+command_name="${1:-}"
+[[ -n "$command_name" ]] || { usage; exit 1; }
+if [[ "$command_name" == "-h" || "$command_name" == "--help" ]]; then
+  usage
+  exit 0
+fi
+shift
+
+market="" actor="" title="" summary="" direction="offer" mechanism="fixed"
+quantity="" price="" budget="" decrement="" delivery="" closes=""
+listing="" response="" award="" fulfillment="" amount="" message=""
+pubkeys=()
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --market) market="${2:-}"; shift 2 ;;
+    --actor) actor="${2:-}"; shift 2 ;;
+    --title) title="${2:-}"; shift 2 ;;
+    --summary) summary="${2:-}"; shift 2 ;;
+    --direction) direction="${2:-}"; shift 2 ;;
+    --mechanism) mechanism="${2:-}"; shift 2 ;;
+    --quantity) quantity="${2:-}"; shift 2 ;;
+    --price) price="${2:-}"; shift 2 ;;
+    --budget) budget="${2:-}"; shift 2 ;;
+    --decrement) decrement="${2:-}"; shift 2 ;;
+    --delivery-minutes) delivery="${2:-}"; shift 2 ;;
+    --closes-at) closes="${2:-}"; shift 2 ;;
+    --listing) listing="${2:-}"; shift 2 ;;
+    --response) response="${2:-}"; shift 2 ;;
+    --award) award="${2:-}"; shift 2 ;;
+    --fulfillment) fulfillment="${2:-}"; shift 2 ;;
+    --amount) amount="${2:-}"; shift 2 ;;
+    --message) message="${2:-}"; shift 2 ;;
+    --pubkey) pubkeys+=("${2:-}"); shift 2 ;;
+    -h|--help) usage; exit 0 ;;
+    *) die "unknown argument: $1" ;;
+  esac
+done
+
+case "$command_name" in
+  listing)
+    need market "$market"; need actor "$actor"; need title "$title"; need summary "$summary"; need quantity "$quantity"
+    payload=$(jq -cn \
+      --arg protocol 'buzz-market/v0' --arg marketId "$market" --arg actorName "$actor" \
+      --arg direction "$direction" --arg mechanism "$mechanism" --arg title "$title" \
+      --arg summary "$summary" --arg quantity "$quantity" --arg price "$price" \
+      --arg budget "$budget" --arg decrement "$decrement" --arg delivery "$delivery" \
+      --arg closes "$closes" \
+      '{protocol:$protocol,type:"listing",marketId:$marketId,version:1,listing:{actorName:$actorName,direction:$direction,mechanism:$mechanism,title:$title,summary:$summary,quantity:(if $quantity=="unlimited" then "unlimited" else ($quantity|tonumber) end)} + (if $price!="" then {priceSats:($price|tonumber)} else {} end) + (if $budget!="" then {maxBudgetSats:($budget|tonumber)} else {} end) + (if $decrement!="" then {minimumDecrementSats:($decrement|tonumber)} else {} end) + (if $delivery!="" then {deliveryMinutes:($delivery|tonumber)} else {} end) + (if $closes!="" then {closesAt:($closes|tonumber)} else {} end)}')
+    json_write "$payload"
+    ;;
+  response)
+    need market "$market"; need listing "$listing"; need actor "$actor"; need quantity "$quantity"; need message "$message"
+    payload=$(jq -cn --arg protocol 'buzz-market/v0' --arg marketId "$market" --arg listingEventId "$listing" --arg actorName "$actor" --arg quantity "$quantity" --arg amount "$amount" --arg message "$message" \
+      '{protocol:$protocol,type:"response",marketId:$marketId,listingEventId:$listingEventId,actorName:$actorName,quantity:($quantity|tonumber),message:$message} + (if $amount!="" then {amountSats:($amount|tonumber)} else {} end)')
+    json_write "$payload"
+    ;;
+  award)
+    need market "$market"; need listing "$listing"; need response "$response"; need actor "$actor"; need quantity "$quantity"; need amount "$amount"
+    payload=$(jq -cn --arg protocol 'buzz-market/v0' --arg marketId "$market" --arg listingEventId "$listing" --arg responseEventId "$response" --arg actorName "$actor" --arg quantity "$quantity" --arg amount "$amount" \
+      '{protocol:$protocol,type:"award",marketId:$marketId,listingEventId:$listingEventId,responseEventId:$responseEventId,actorName:$actorName,quantity:($quantity|tonumber),amountSats:($amount|tonumber)}')
+    json_write "$payload"
+    ;;
+  fulfill)
+    need market "$market"; need listing "$listing"; need award "$award"; need actor "$actor"; need message "$message"
+    payload=$(jq -cn --arg protocol 'buzz-market/v0' --arg marketId "$market" --arg listingEventId "$listing" --arg awardEventId "$award" --arg actorName "$actor" --arg message "$message" \
+      '{protocol:$protocol,type:"fulfillment",marketId:$marketId,listingEventId:$listingEventId,awardEventId:$awardEventId,actorName:$actorName,message:$message}')
+    json_write "$payload"
+    ;;
+  settle)
+    need market "$market"; need listing "$listing"; need award "$award"; need fulfillment "$fulfillment"; need actor "$actor"; need amount "$amount"
+    payload=$(jq -cn --arg protocol 'buzz-market/v0' --arg marketId "$market" --arg listingEventId "$listing" --arg awardEventId "$award" --arg fulfillmentEventId "$fulfillment" --arg actorName "$actor" --arg amount "$amount" \
+      '{protocol:$protocol,type:"settlement",marketId:$marketId,listingEventId:$listingEventId,awardEventId:$awardEventId,fulfillmentEventId:$fulfillmentEventId,actorName:$actorName,amountSats:($amount|tonumber)}')
+    json_write "$payload"
+    ;;
+  watch)
+    ((${#pubkeys[@]} > 0)) || die "watch requires at least one --pubkey"
+    combined='[]'
+    for pubkey in "${pubkeys[@]}"; do
+      events=$(buzz social notes --pubkey "$pubkey" --limit 100)
+      combined=$(jq -cn --argjson left "$combined" --argjson right "$events" '$left + $right')
+    done
+    jq '[.[] | select(.kind == 1) | . as $event | (try (.content | fromjson) catch null) as $body | select($body.protocol == "buzz-market/v0") | {id, pubkey, created_at, marketId:$body.marketId, type:$body.type, body:$body}] | sort_by(.created_at, ({listing:0,response:1,award:2,fulfillment:3,settlement:4}[.type] // 99), .id)' <<<"$combined"
+    ;;
+  *) usage; die "unknown command: $command_name" ;;
+esac