diff --git a/test/relay-fanout-quorum.integration.test.mjs b/test/relay-fanout-quorum.integration.test.mjs
new file mode 100644
index 0000000..ca2769e
--- /dev/null
+++ b/test/relay-fanout-quorum.integration.test.mjs
@@ -0,0 +1,239 @@
+import { afterEach, beforeEach, describe, it } from 'node:test';
+import assert from 'node:assert';
+import net from 'node:net';
+import { WebSocketServer } from 'ws';
+
+import { publishLock, _resetRelayHealthState } from '../src/lock-ops.mjs';
+
+async function getFreePort() {
+  return new Promise((resolve, reject) => {
+    const server = net.createServer();
+    server.listen(0, '127.0.0.1', () => {
+      const address = server.address();
+      const port = typeof address === 'object' && address ? address.port : null;
+      server.close((closeErr) => {
+        if (closeErr) {
+          reject(closeErr);
+          return;
+        }
+        resolve(port);
+      });
+    });
+    server.on('error', reject);
+  });
+}
+
+async function createRelaySimulatorFixture(modes) {
+  if (modes.length !== 3) {
+    throw new Error(`Expected exactly three relays, got ${modes.length}`);
+  }
+
+  const servers = [];
+  const relays = [];
+
+  for (const mode of modes) {
+    const port = await getFreePort();
+    const relayUrl = `ws://127.0.0.1:${port}`;
+
+    if (mode.type === 'connection-fail') {
+      relays.push(relayUrl);
+      continue;
+    }
+
+    const wss = new WebSocketServer({ host: '127.0.0.1', port });
+    wss.on('connection', (socket) => {
+      socket.on('message', (rawData) => {
+        let payload;
+        try {
+          payload = JSON.parse(rawData.toString());
+        } catch {
+          return;
+        }
+
+        if (!Array.isArray(payload) || payload[0] !== 'EVENT') {
+          return;
+        }
+
+        const event = payload[1] || {};
+        if (mode.type === 'success') {
+          const delayMs = mode.delayMs ?? 0;
+          setTimeout(() => {
+            if (socket.readyState === socket.OPEN) {
+              socket.send(JSON.stringify(['OK', event.id, true, 'accepted']));
+            }
+          }, delayMs);
+        }
+      });
+    });
+
+    servers.push(wss);
+    relays.push(relayUrl);
+  }
+
+  return {
+    relays,
+    async stop() {
+      await Promise.all(servers.map((server) => new Promise((resolve, reject) => {
+        server.close((err) => {
+          if (err) reject(err);
+          else resolve();
+        });
+      })));
+    },
+  };
+}
+
+function parseTelemetry(lines) {
+  return lines.map((line) => JSON.parse(line));
+}
+
+function makeEvent(id) {
+  return {
+    id,
+    kind: 1,
+    pubkey: 'f'.repeat(64),
+    created_at: Math.floor(Date.now() / 1000),
+    tags: [],
+    content: 'relay-test',
+    sig: 'e'.repeat(128),
+  };
+}
+
+describe('relay fanout quorum integration', { concurrency: false }, () => {
+  let fixture = null;
+
+  beforeEach(() => {
+    _resetRelayHealthState();
+  });
+
+  afterEach(async () => {
+    if (fixture) {
+      await fixture.stop();
+      fixture = null;
+    }
+  });
+
+  it('passes with required=1 when one relay succeeds and two fail', async () => {
+    fixture = await createRelaySimulatorFixture([
+      { type: 'success' },
+      { type: 'timeout' },
+      { type: 'timeout' },
+    ]);
+
+    const telemetryLogs = [];
+    const result = await publishLock(fixture.relays, makeEvent('evt-required1-pass'), {
+      getPublishTimeoutMsFn: () => 80,
+      getMinSuccessfulRelayPublishesFn: () => 1,
+      getRelayFallbacksFn: () => [],
+      getMinActiveRelayPoolFn: () => 1,
+      retryAttempts: 1,
+      telemetryLogger: (line) => telemetryLogs.push(line),
+      healthLogger: () => {},
+    });
+
+    assert.strictEqual(result.id, 'evt-required1-pass');
+
+    const telemetry = parseTelemetry(telemetryLogs);
+    const quorumSummary = telemetry.find((entry) => entry.event === 'lock_publish_quorum_met');
+    assert.ok(quorumSummary);
+    assert.strictEqual(quorumSummary.successCount, 1);
+    assert.strictEqual(quorumSummary.requiredSuccesses, 1);
+    assert.strictEqual(quorumSummary.relayAttemptedCount, 3);
+  });
+
+  it('fails with quorum error for required=1 when all relays fail', async () => {
+    fixture = await createRelaySimulatorFixture([
+      { type: 'timeout' },
+      { type: 'timeout' },
+      { type: 'timeout' },
+    ]);
+
+    const telemetryLogs = [];
+    await assert.rejects(
+      () => publishLock(fixture.relays, makeEvent('evt-required1-all-fail'), {
+        getPublishTimeoutMsFn: () => 80,
+        getMinSuccessfulRelayPublishesFn: () => 1,
+        getRelayFallbacksFn: () => [],
+        getMinActiveRelayPoolFn: () => 1,
+        retryAttempts: 1,
+        telemetryLogger: (line) => telemetryLogs.push(line),
+        healthLogger: () => {},
+      }),
+      /error_category=relay_publish_quorum_failure/,
+    );
+
+    const telemetry = parseTelemetry(telemetryLogs);
+    const relayOutcomes = telemetry.filter((entry) => entry.event === 'lock_publish_failure');
+    assert.strictEqual(relayOutcomes.length, 3);
+    assert.ok(relayOutcomes.every((entry) => fixture.relays.includes(entry.relayUrl)));
+
+    const quorumSummary = telemetry.find((entry) => entry.event === 'lock_publish_quorum_failed');
+    assert.ok(quorumSummary);
+    assert.strictEqual(quorumSummary.successCount, 0);
+    assert.strictEqual(quorumSummary.requiredSuccesses, 1);
+    assert.strictEqual(quorumSummary.relayAttemptedCount, 3);
+  });
+
+  it('fails with required=2 when only one relay succeeds', async () => {
+    fixture = await createRelaySimulatorFixture([
+      { type: 'success' },
+      { type: 'timeout' },
+      { type: 'timeout' },
+    ]);
+
+    const telemetryLogs = [];
+    await assert.rejects(
+      () => publishLock(fixture.relays, makeEvent('evt-required2-fail'), {
+        getPublishTimeoutMsFn: () => 80,
+        getMinSuccessfulRelayPublishesFn: () => 2,
+        getRelayFallbacksFn: () => [],
+        getMinActiveRelayPoolFn: () => 1,
+        retryAttempts: 1,
+        telemetryLogger: (line) => telemetryLogs.push(line),
+        healthLogger: () => {},
+      }),
+      /error_category=relay_publish_quorum_failure/,
+    );
+
+    const telemetry = parseTelemetry(telemetryLogs);
+    const relayOutcomes = telemetry.filter((entry) => entry.event === 'lock_publish_failure');
+    assert.strictEqual(relayOutcomes.length, 2);
+
+    const quorumSummary = telemetry.find((entry) => entry.event === 'lock_publish_quorum_failed');
+    assert.ok(quorumSummary);
+    assert.strictEqual(quorumSummary.successCount, 1);
+    assert.strictEqual(quorumSummary.requiredSuccesses, 2);
+    assert.strictEqual(quorumSummary.relayAttemptedCount, 3);
+  });
+
+  it('passes when delayed successes reach quorum before timeout', async () => {
+    fixture = await createRelaySimulatorFixture([
+      { type: 'success', delayMs: 5 },
+      { type: 'success', delayMs: 25 },
+      { type: 'timeout' },
+    ]);
+
+    const telemetryLogs = [];
+    const startedAt = Date.now();
+    const result = await publishLock(fixture.relays, makeEvent('evt-delayed-quorum'), {
+      getPublishTimeoutMsFn: () => 80,
+      getMinSuccessfulRelayPublishesFn: () => 2,
+      getRelayFallbacksFn: () => [],
+      getMinActiveRelayPoolFn: () => 1,
+      retryAttempts: 1,
+      telemetryLogger: (line) => telemetryLogs.push(line),
+      healthLogger: () => {},
+    });
+    const elapsedMs = Date.now() - startedAt;
+
+    assert.strictEqual(result.id, 'evt-delayed-quorum');
+    assert.ok(elapsedMs < 160);
+
+    const telemetry = parseTelemetry(telemetryLogs);
+    const quorumSummary = telemetry.find((entry) => entry.event === 'lock_publish_quorum_met');
+    assert.ok(quorumSummary);
+    assert.strictEqual(quorumSummary.successCount, 2);
+    assert.strictEqual(quorumSummary.requiredSuccesses, 2);
+    assert.strictEqual(quorumSummary.relayAttemptedCount, 3);
+  });
+});