diff --git a/apps/gateway/src/__tests__/integration/federation-m3-list.integration.test.ts b/apps/gateway/src/__tests__/integration/federation-m3-list.integration.test.ts
new file mode 100644
index 0000000..b597a8f
--- /dev/null
+++ b/apps/gateway/src/__tests__/integration/federation-m3-list.integration.test.ts
@@ -0,0 +1,519 @@
+/**
+ * Federation M3 single-gateway integration tests (FED-M3-10).
+ *
+ * Covers MILESTONES.md M3 acceptance:
+ *  - #6: malformed certificate OIDs fail with 401; valid cert + revoked grant fails with 403.
+ *  - #7: max_rows_per_query caps list results.
+ *
+ * Strategy:
+ *  - Real PostgreSQL via @mosaicstack/db.
+ *  - Mocked TLS context/Fastify request shim for FederationAuthGuard.
+ *  - Direct controller calls using the real POST /api/federation/v1/list/:resource contract.
+ *
+ * Run:
+ *   FEDERATED_INTEGRATION=1 pnpm --filter @mosaicstack/gateway test -- \
+ *     src/__tests__/integration/federation-m3-list.integration.test.ts
+ */
+
+import 'reflect-metadata';
+import * as crypto from 'node:crypto';
+import type { ExecutionContext } from '@nestjs/common';
+import { Test, type TestingModule } from '@nestjs/testing';
+import type { FastifyReply, FastifyRequest } from 'fastify';
+import {
+  and,
+  createDb,
+  eq,
+  federationGrants,
+  federationPeers,
+  inArray,
+  missionTasks,
+  missions,
+  projects,
+  tasks,
+  teamMembers,
+  teams,
+  type Db,
+  type DbHandle,
+  users,
+} from '@mosaicstack/db';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+import { DB } from '../../database/database.module.js';
+import { GrantsService } from '../../federation/grants.service.js';
+import { FederationAuthGuard } from '../../federation/server/federation-auth.guard.js';
+import { FederationScopeService } from '../../federation/server/scope.service.js';
+import { FederationListQueryService } from '../../federation/server/verbs/list-query.service.js';
+import { ListController } from '../../federation/server/verbs/list.controller.js';
+import {
+  makeMosaicIssuedCert,
+  makeSelfSignedCert,
+} from '../../federation/__tests__/helpers/test-cert.js';
+
+const run = process.env['FEDERATED_INTEGRATION'] === '1';
+const PG_URL = process.env['DATABASE_URL'] ?? 'postgresql://mosaic:mosaic@localhost:5433/mosaic';
+const RUN_ID = `fed-m3-10-${crypto.randomUUID()}`;
+const CERT_SERIAL_HEX = crypto.randomUUID().replace(/-/g, '').toUpperCase();
+
+interface TestIds {
+  readonly subjectUserId: string;
+  readonly otherUserId: string;
+  readonly peerId: string;
+  readonly revokedPeerId: string;
+  readonly activeGrantId: string;
+  readonly revokedGrantId: string;
+  readonly subjectProjectId: string;
+  readonly subjectMissionId: string;
+  readonly otherProjectId: string;
+  readonly teamId: string;
+  readonly unauthorizedTeamId: string;
+  readonly teamProjectId: string;
+  readonly taskIds: readonly string[];
+  readonly excludedTaskIds: readonly string[];
+  readonly subjectNoteId: string;
+  readonly otherUserNoteId: string;
+}
+
+function pemToDer(pem: string): Buffer {
+  return Buffer.from(
+    pem
+      .replace(/-----BEGIN CERTIFICATE-----/, '')
+      .replace(/-----END CERTIFICATE-----/, '')
+      .replace(/\s+/g, ''),
+    'base64',
+  );
+}
+
+function makeFederationRequest(certPem: string): FastifyRequest {
+  return {
+    raw: {
+      socket: {
+        getPeerCertificate: () => ({
+          raw: pemToDer(certPem),
+          serialNumber: CERT_SERIAL_HEX,
+        }),
+      },
+    },
+  } as unknown as FastifyRequest;
+}
+
+function makeGuardContext(request: FastifyRequest): {
+  readonly context: ExecutionContext;
+  readonly sent: { statusCode?: number; payload?: unknown };
+} {
+  const sent: { statusCode?: number; payload?: unknown } = {};
+  const reply = {
+    status: (statusCode: number) => {
+      sent.statusCode = statusCode;
+      return {
+        header: () => ({
+          send: (payload: unknown) => {
+            sent.payload = payload;
+          },
+        }),
+      };
+    },
+  } as unknown as FastifyReply;
+
+  const context = {
+    switchToHttp: () => ({
+      getRequest: () => request,
+      getResponse: () => reply,
+    }),
+  } as unknown as ExecutionContext;
+
+  return { context, sent };
+}
+
+async function insertUser(db: Db, id: string, label: string): Promise<void> {
+  await db.insert(users).values({
+    id,
+    name: `${RUN_ID}-${label}`,
+    email: `${RUN_ID}-${label}@federation-test.invalid`,
+    emailVerified: false,
+  });
+}
+
+async function seedFixtures(db: Db): Promise<TestIds> {
+  const subjectUserId = `${RUN_ID}-subject`;
+  const otherUserId = `${RUN_ID}-other`;
+  const peerId = crypto.randomUUID();
+  const revokedPeerId = crypto.randomUUID();
+  const activeGrantId = crypto.randomUUID();
+  const revokedGrantId = crypto.randomUUID();
+  const subjectProjectId = crypto.randomUUID();
+  const subjectMissionId = crypto.randomUUID();
+  const otherProjectId = crypto.randomUUID();
+  const teamId = crypto.randomUUID();
+  const unauthorizedTeamId = crypto.randomUUID();
+  const teamProjectId = crypto.randomUUID();
+  const taskIds = [crypto.randomUUID(), crypto.randomUUID(), crypto.randomUUID()] as const;
+  const excludedTaskIds = [crypto.randomUUID(), crypto.randomUUID()] as const;
+  const subjectNoteId = crypto.randomUUID();
+  const otherUserNoteId = crypto.randomUUID();
+
+  await insertUser(db, subjectUserId, 'subject');
+  await insertUser(db, otherUserId, 'other');
+
+  await db.insert(teams).values([
+    {
+      id: teamId,
+      name: `${RUN_ID} allowed team`,
+      slug: `${RUN_ID}-allowed-team`,
+      ownerId: subjectUserId,
+      managerId: subjectUserId,
+    },
+    {
+      id: unauthorizedTeamId,
+      name: `${RUN_ID} unauthorized team`,
+      slug: `${RUN_ID}-unauthorized-team`,
+      ownerId: otherUserId,
+      managerId: otherUserId,
+    },
+  ]);
+
+  await db.insert(teamMembers).values([
+    { teamId, userId: subjectUserId, role: 'member' },
+    { teamId: unauthorizedTeamId, userId: subjectUserId, role: 'member' },
+  ]);
+
+  await db.insert(projects).values([
+    {
+      id: subjectProjectId,
+      name: `${RUN_ID} subject personal project`,
+      ownerType: 'user',
+      ownerId: subjectUserId,
+    },
+    {
+      id: otherProjectId,
+      name: `${RUN_ID} other personal project`,
+      ownerType: 'user',
+      ownerId: otherUserId,
+    },
+    {
+      id: teamProjectId,
+      name: `${RUN_ID} unauthorized team project`,
+      ownerType: 'team',
+      teamId: unauthorizedTeamId,
+    },
+  ]);
+
+  await db.insert(missions).values({
+    id: subjectMissionId,
+    name: `${RUN_ID} subject mission`,
+    projectId: subjectProjectId,
+    userId: subjectUserId,
+  });
+
+  await db.insert(tasks).values([
+    {
+      id: taskIds[0],
+      title: `${RUN_ID} visible task 1`,
+      missionId: subjectMissionId,
+      createdAt: new Date('2026-06-25T03:00:00.000Z'),
+      updatedAt: new Date('2026-06-25T03:00:00.000Z'),
+    },
+    {
+      id: taskIds[1],
+      title: `${RUN_ID} visible task 2`,
+      projectId: subjectProjectId,
+      createdAt: new Date('2026-06-25T02:00:00.000Z'),
+      updatedAt: new Date('2026-06-25T02:00:00.000Z'),
+    },
+    {
+      id: taskIds[2],
+      title: `${RUN_ID} visible task 3`,
+      projectId: subjectProjectId,
+      createdAt: new Date('2026-06-25T01:00:00.000Z'),
+      updatedAt: new Date('2026-06-25T01:00:00.000Z'),
+    },
+    {
+      id: excludedTaskIds[0],
+      title: `${RUN_ID} other user task`,
+      projectId: otherProjectId,
+      createdAt: new Date('2026-06-25T04:00:00.000Z'),
+      updatedAt: new Date('2026-06-25T04:00:00.000Z'),
+    },
+    {
+      id: excludedTaskIds[1],
+      title: `${RUN_ID} unauthorized team task`,
+      projectId: teamProjectId,
+      createdAt: new Date('2026-06-25T05:00:00.000Z'),
+      updatedAt: new Date('2026-06-25T05:00:00.000Z'),
+    },
+  ]);
+
+  await db.insert(missionTasks).values([
+    {
+      id: subjectNoteId,
+      missionId: subjectMissionId,
+      userId: subjectUserId,
+      notes: `${RUN_ID} subject visible note`,
+      createdAt: new Date('2026-06-25T03:30:00.000Z'),
+      updatedAt: new Date('2026-06-25T03:30:00.000Z'),
+    },
+    {
+      id: otherUserNoteId,
+      missionId: subjectMissionId,
+      userId: otherUserId,
+      notes: `${RUN_ID} other user note on subject mission`,
+      createdAt: new Date('2026-06-25T04:30:00.000Z'),
+      updatedAt: new Date('2026-06-25T04:30:00.000Z'),
+    },
+  ]);
+
+  await db.insert(federationPeers).values([
+    {
+      id: peerId,
+      commonName: `${RUN_ID}-active-peer`,
+      displayName: `${RUN_ID} Active Peer`,
+      certPem: '-----BEGIN CERTIFICATE-----\nMOCK\n-----END CERTIFICATE-----\n',
+      certSerial: CERT_SERIAL_HEX,
+      certNotAfter: new Date(Date.now() + 86_400_000),
+      state: 'active',
+    },
+    {
+      id: revokedPeerId,
+      commonName: `${RUN_ID}-revoked-peer`,
+      displayName: `${RUN_ID} Revoked Peer`,
+      certPem: '-----BEGIN CERTIFICATE-----\nMOCK\n-----END CERTIFICATE-----\n',
+      certSerial: `${CERT_SERIAL_HEX}${RUN_ID.replace(/-/g, '').slice(0, 8).toUpperCase()}`,
+      certNotAfter: new Date(Date.now() + 86_400_000),
+      state: 'active',
+    },
+  ]);
+
+  await db.insert(federationGrants).values([
+    {
+      id: activeGrantId,
+      peerId,
+      subjectUserId,
+      status: 'active',
+      scope: {
+        resources: ['tasks', 'notes'],
+        excluded_resources: [],
+        filters: {
+          tasks: { include_personal: true, include_teams: [] },
+          notes: { include_personal: true, include_teams: [] },
+        },
+        max_rows_per_query: 2,
+      },
+    },
+    {
+      id: revokedGrantId,
+      peerId,
+      subjectUserId,
+      status: 'revoked',
+      revokedAt: new Date(),
+      revokedReason: `${RUN_ID} revoked grant fixture`,
+      scope: {
+        resources: ['tasks'],
+        excluded_resources: [],
+        max_rows_per_query: 2,
+      },
+    },
+  ]);
+
+  return {
+    subjectUserId,
+    otherUserId,
+    peerId,
+    revokedPeerId,
+    activeGrantId,
+    revokedGrantId,
+    subjectProjectId,
+    subjectMissionId,
+    otherProjectId,
+    teamId,
+    unauthorizedTeamId,
+    teamProjectId,
+    taskIds,
+    excludedTaskIds,
+    subjectNoteId,
+    otherUserNoteId,
+  };
+}
+
+async function cleanupFixtures(db: Db, ids: TestIds | undefined): Promise<void> {
+  if (!ids) {
+    return;
+  }
+
+  await db
+    .delete(missionTasks)
+    .where(inArray(missionTasks.id, [ids.subjectNoteId, ids.otherUserNoteId]))
+    .catch(() => {});
+  await db
+    .delete(tasks)
+    .where(inArray(tasks.id, [...ids.taskIds, ...ids.excludedTaskIds]))
+    .catch(() => {});
+  await db
+    .delete(missions)
+    .where(eq(missions.id, ids.subjectMissionId))
+    .catch(() => {});
+  await db
+    .delete(projects)
+    .where(inArray(projects.id, [ids.subjectProjectId, ids.otherProjectId, ids.teamProjectId]))
+    .catch(() => {});
+  await db
+    .delete(teamMembers)
+    .where(
+      and(
+        eq(teamMembers.userId, ids.subjectUserId),
+        inArray(teamMembers.teamId, [ids.teamId, ids.unauthorizedTeamId]),
+      ),
+    )
+    .catch(() => {});
+  await db
+    .delete(teams)
+    .where(inArray(teams.id, [ids.teamId, ids.unauthorizedTeamId]))
+    .catch(() => {});
+  await db
+    .delete(federationGrants)
+    .where(inArray(federationGrants.id, [ids.activeGrantId, ids.revokedGrantId]))
+    .catch(() => {});
+  await db
+    .delete(federationPeers)
+    .where(inArray(federationPeers.id, [ids.peerId, ids.revokedPeerId]))
+    .catch(() => {});
+  await db
+    .delete(users)
+    .where(inArray(users.id, [ids.subjectUserId, ids.otherUserId]))
+    .catch(() => {});
+}
+
+describe.skipIf(!run)('federation M3 list verb — single-gateway integration', () => {
+  let handle: DbHandle;
+  let db: Db;
+  let moduleRef: TestingModule;
+  let guard: FederationAuthGuard;
+  let listController: ListController;
+  let ids: TestIds | undefined;
+
+  beforeAll(async () => {
+    handle = createDb(PG_URL);
+    db = handle.db;
+    ids = await seedFixtures(db);
+
+    moduleRef = await Test.createTestingModule({
+      controllers: [ListController],
+      providers: [
+        { provide: DB, useValue: db },
+        GrantsService,
+        FederationAuthGuard,
+        FederationScopeService,
+        FederationListQueryService,
+      ],
+    }).compile();
+
+    guard = moduleRef.get(FederationAuthGuard);
+    listController = moduleRef.get(ListController);
+  }, 30_000);
+
+  afterAll(async () => {
+    await moduleRef?.close().catch((e: unknown) => console.error('[fed-m3-10 cleanup]', e));
+    await cleanupFixtures(db, ids).catch((e: unknown) => console.error('[fed-m3-10 cleanup]', e));
+    await handle?.close().catch((e: unknown) => console.error('[fed-m3-10 cleanup]', e));
+  });
+
+  it('#6 — rejects a client cert with malformed/missing Mosaic OIDs with 401', async () => {
+    const malformedOidCert = await makeSelfSignedCert();
+    const request = makeFederationRequest(malformedOidCert);
+    const { context, sent } = makeGuardContext(request);
+
+    await expect(guard.canActivate(context)).resolves.toBe(false);
+    expect(sent.statusCode).toBe(401);
+    expect(sent.payload).toMatchObject({
+      error: {
+        code: 'unauthorized',
+        message: expect.stringContaining('missing required OID'),
+      },
+    });
+    expect(request.federationContext).toBeUndefined();
+  });
+
+  it('#6 — rejects a valid client cert when its grant is revoked with 403', async () => {
+    expect(ids).toBeDefined();
+    const revokedCert = await makeMosaicIssuedCert({
+      grantId: ids!.revokedGrantId,
+      subjectUserId: ids!.subjectUserId,
+    });
+    const request = makeFederationRequest(revokedCert);
+    const { context, sent } = makeGuardContext(request);
+
+    await expect(guard.canActivate(context)).resolves.toBe(false);
+    expect(sent.statusCode).toBe(403);
+    expect(sent.payload).toMatchObject({
+      error: {
+        code: 'forbidden',
+        message: 'Federation access denied',
+      },
+    });
+    expect(request.federationContext).toBeUndefined();
+  });
+
+  it('#7 — enforces max_rows_per_query on POST /api/federation/v1/list/:resource', async () => {
+    expect(ids).toBeDefined();
+    const activeCert = await makeMosaicIssuedCert({
+      grantId: ids!.activeGrantId,
+      subjectUserId: ids!.subjectUserId,
+    });
+    const request = makeFederationRequest(activeCert);
+    const { context } = makeGuardContext(request);
+
+    await expect(guard.canActivate(context)).resolves.toBe(true);
+
+    const response = await listController.list('tasks', request, { limit: 100 });
+    const returnedIds = response.items.map((item) => item['id']);
+
+    expect(response.items).toHaveLength(2);
+    expect(response._truncated).toBe(true);
+    expect(response.nextCursor).toEqual(expect.any(String));
+    expect(returnedIds).toEqual([ids!.taskIds[0], ids!.taskIds[1]]);
+    expect(returnedIds).not.toContain(ids!.taskIds[2]);
+    for (const excludedId of ids!.excludedTaskIds) {
+      expect(returnedIds).not.toContain(excludedId);
+    }
+    expect(response.items.every((item) => item._source === 'local')).toBe(true);
+  });
+
+  it('excludes another user mission task notes on the same authorized mission', async () => {
+    expect(ids).toBeDefined();
+    const activeCert = await makeMosaicIssuedCert({
+      grantId: ids!.activeGrantId,
+      subjectUserId: ids!.subjectUserId,
+    });
+    const request = makeFederationRequest(activeCert);
+    const { context } = makeGuardContext(request);
+
+    await expect(guard.canActivate(context)).resolves.toBe(true);
+
+    const response = await listController.list('notes', request, { limit: 10 });
+    const returnedIds = response.items.map((item) => item['id']);
+
+    expect(returnedIds).toEqual([ids!.subjectNoteId]);
+    expect(returnedIds).not.toContain(ids!.otherUserNoteId);
+    expect(response.items.every((item) => item._source === 'local')).toBe(true);
+  });
+
+  it('fails closed for unsupported list resources', async () => {
+    expect(ids).toBeDefined();
+    const activeCert = await makeMosaicIssuedCert({
+      grantId: ids!.activeGrantId,
+      subjectUserId: ids!.subjectUserId,
+    });
+    const request = makeFederationRequest(activeCert);
+    const { context } = makeGuardContext(request);
+
+    await expect(guard.canActivate(context)).resolves.toBe(true);
+
+    await expect(listController.list('widgets', request, {})).rejects.toMatchObject({
+      response: {
+        error: {
+          code: 'scope_violation',
+          message: 'Requested federation resource is not supported',
+        },
+      },
+      status: 403,
+    });
+  });
+});
diff --git a/docs/scratchpads/FED-M3-10-integration-tests.md b/docs/scratchpads/FED-M3-10-integration-tests.md
new file mode 100644
index 0000000..eaeb416
--- /dev/null
+++ b/docs/scratchpads/FED-M3-10-integration-tests.md
@@ -0,0 +1,60 @@
+# FED-M3-10 — Federation M3 Integration Tests
+
+## Objective
+
+Add single-gateway gateway integration tests for M3 acceptance #6 and #7.
+
+## Branch / base
+
+- Branch: `feat/federation-m3-integration`
+- Base: `origin/next` (`838701bd` after M3-06/#683 merge)
+- PR base when unblocked: `next`
+
+## Scope
+
+- Real PostgreSQL via `@mosaicstack/db`.
+- Mocked TLS context / Fastify request shim for `FederationAuthGuard`.
+- Direct controller calls using the real M3 route contract: `POST /api/federation/v1/list/:resource` with body `{ limit?, cursor? }`.
+- Gated by `FEDERATED_INTEGRATION=1`.
+- No federation harness dependency.
+
+## Fixture notes
+
+Aligned with the B2 seed design vocabulary:
+
+- `tasks` visibility uses personal `projects` + `missions` chain.
+- `notes` are `mission_tasks.notes`; the integration suite asserts subject-only note visibility on an authorized mission.
+- Seed includes a second user and unauthorized team/project tasks to prove exclusion from the max-row-cap list result.
+- Grants/peers are direct DB fixtures; cert auth still runs through `FederationAuthGuard` using real X.509 certs generated by existing test helpers.
+
+## Current implementation
+
+Added `apps/gateway/src/__tests__/integration/federation-m3-list.integration.test.ts` covering:
+
+1. M3 #6 — cert missing Mosaic OIDs returns 401 federation `unauthorized` envelope.
+2. M3 #6 — valid cert whose grant row is `revoked` returns 403 federation `forbidden` envelope.
+3. M3 #7 — active grant with `max_rows_per_query: 2` caps `list tasks`, returns `_truncated` + `nextCursor`, source-tags rows, and excludes other-user / unauthorized-team tasks.
+4. Cross-user notes invariant — subject can list their own `mission_tasks.notes` row while another user's note on the same authorized mission is excluded.
+5. Unsupported-resource invariant — `list widgets` fails closed with a federation `scope_violation` envelope.
+
+## Verification
+
+- `pnpm --filter @mosaicstack/types build` — PASS.
+- `pnpm --filter @mosaicstack/db build` — PASS.
+- `pnpm --filter @mosaicstack/storage build` — PASS.
+- `pnpm --filter @mosaicstack/brain build` — PASS.
+- `pnpm --filter @mosaicstack/queue build` — PASS.
+- `pnpm --filter @mosaicstack/config build` — PASS.
+- `pnpm --filter @mosaicstack/auth build` — PASS.
+- `pnpm --filter @mosaicstack/gateway test -- src/__tests__/integration/federation-m3-list.integration.test.ts` — PASS skipped when `FEDERATED_INTEGRATION` unset (5 skipped).
+- `FEDERATED_INTEGRATION=1 pnpm --filter @mosaicstack/gateway test -- src/__tests__/integration/federation-m3-list.integration.test.ts` — PASS (5 tests) after local `docker compose up -d postgres` + `pnpm --filter @mosaicstack/db db:push`.
+- `pnpm --filter @mosaicstack/gateway typecheck` — PASS.
+- `pnpm --filter @mosaicstack/gateway lint` — PASS.
+- `pnpm format:check` — PASS.
+- `~/.config/mosaic/tools/codex/codex-code-review.sh --uncommitted` — PASS; approve, no findings.
+- `~/.config/mosaic/tools/codex/codex-security-review.sh --uncommitted` — PASS; risk level none, no findings.
+
+## Push / PR
+
+- #683 landed in `next`; branch rebased onto `origin/next` before push.
+- CI is serialized; run queue guard before push.