apps/gateway/src/agent/hermes-runtime-reachability.e2e.test.ts

@@ -115,6 +115,38 @@ describe('Hermes runtime provider reachability', (): void => {
     await app?.close();
   });
 
+  it('returns gateway denial responses from the actual guarded interaction routes', async (): Promise<void> => {
+    if (!app) throw new Error('Nest application did not initialize');
+
+    const attachDenied = await app.inject({
+      method: 'POST',
+      url: '/api/interaction/Nova/sessions/session-1/attach',
+      headers: { 'x-correlation-id': 'correlation-1' },
+      payload: { mode: 'read' },
+    });
+    expect(attachDenied.statusCode).toBe(401);
+
+    const sendDenied = await app.inject({
+      method: 'POST',
+      url: '/api/interaction/Nova/sessions/session-1/send',
+      headers: { cookie: 'session=trusted', 'x-correlation-id': 'correlation-1' },
+      payload: {},
+    });
+    expect(sendDenied.statusCode).toBe(403);
+    expect(sendDenied.json()).toMatchObject({
+      message: 'Content and idempotency key are required',
+    });
+
+    const stopDenied = await app.inject({
+      method: 'POST',
+      url: '/api/interaction/Nova/sessions/session-1/stop',
+      headers: { cookie: 'session=trusted', 'x-correlation-id': 'correlation-1' },
+      payload: {},
+    });
+    expect(stopDenied.statusCode).toBe(403);
+    expect(stopDenied.json()).toMatchObject({ message: 'Exact-action approval is required' });
+  });
+
   it('requires authentication and reaches the Hermes provider registered by AgentModule', async (): Promise<void> => {
     if (!app) throw new Error('Nest application did not initialize');
     const registry = app.get(AGENT_RUNTIME_PROVIDER_REGISTRY);

docs/openapi-tess.yaml

@@ -124,7 +124,7 @@ paths:
         {
           summary: Submit Mos handoff,
           parameters: [{ $ref: '#/components/parameters/correlation' }],
-          requestBody: { $ref: '#/components/requestBodies/MosHandoff' },
+          requestBody: { $ref: '#/components/requestBodies/Handoff' },
           responses: { '200': { description: Receipt } },
         },
     }
@@ -261,7 +261,7 @@ components:
               },
           },
       }
-    MosHandoff:
+    Handoff:
       {
         required: true,
         content:

docs/scratchpads/tess-m4-001-mos-coordination.md

@@ -18,11 +18,11 @@ Implement a transport-neutral coordination contract allowing a configured intera
 
 ## Design checkpoint — 2026-07-12
 
-Created `docs/tess/MOS-COORDINATION.md`. Mos approved the design and selected the native in-process `InMemoryMosCoordinationPort` for M4. Fleet/tmux remains a documented M5 adapter seam; no Mos-side consumer is built in this task.
+Created `docs/tess/MOS-COORDINATION.md`. Mos approved the design and selected the native in-process `InMemoryInteractionCoordinationPort` for M4. Fleet/tmux remains a documented M5 adapter seam; no Mos-side consumer is built in this task.
 
 ## Progress checkpoint — 2026-07-13
 
-- Implemented `MosCoordinationPort` with handoff/observe/result only, an authority-checking client, and deterministic native adapter in `@mosaicstack/coord`.
+- Implemented `InteractionCoordinationPort` with handoff/observe/result only, an authority-checking client, and deterministic native adapter in `@mosaicstack/coord`.
 - Implemented the gateway `InteractionCoordinationService`, deriving requester identity from trusted configuration and actor/tenant/correlation from authenticated context.
 - Added contract and gateway boundary tests for configurable identities, native round-trip, unconfigured requester, self-delegation, target drift, and cross-tenant observe/result denial before adapter invocation.
 - Did not modify `apps/gateway/src/commands/command-authorization.service.ts`.

docs/tess/ARCHITECTURE.md

@@ -54,7 +54,7 @@ Termination is fail-closed: a runtime approval verifier consumes a one-time, exa
 
 ### Mos Coordination Boundary
 
-`@mosaicstack/coord` exposes only the transport-neutral `MosCoordinationPort`
+`@mosaicstack/coord` exposes only the transport-neutral `InteractionCoordinationPort`
 verbs `handoff`, `observe`, and `result`. Gateway derives the actor, tenant,
 correlation, and interaction-agent identity from authenticated context plus
 trusted configuration; callers never provide an orchestration target. It

docs/tess/MOS-COORDINATION.md

@@ -20,29 +20,29 @@ interface CoordinationScope {
   readonly requesterAgentId: string; // trusted gateway/configuration data
 }
 
-interface MosHandoffRequest {
+interface HandoffRequest {
   readonly idempotencyKey: string;
   readonly summary: string;
   readonly context?: string;
   readonly missionId?: string;
 }
 
-interface MosHandoffReceipt {
+interface HandoffReceipt {
   readonly handoffId: string;
   readonly targetAgentId: string;
   readonly status: 'accepted' | 'queued';
   readonly correlationId: string;
 }
 
-interface MosHandoff {
+interface Handoff {
   readonly handoffId: string;
   readonly targetAgentId: string;
-  readonly request: MosHandoffRequest;
+  readonly request: HandoffRequest;
   readonly scope: CoordinationScope;
 }
 
-interface MosCoordinationPort {
-  handoff(handoff: MosHandoff): Promise<MosHandoffReceipt>;
+interface InteractionCoordinationPort {
+  handoff(handoff: Handoff): Promise<HandoffReceipt>;
   observe(handoffId: string, scope: CoordinationScope): Promise<CoordinationObservation>;
   result(handoffId: string, scope: CoordinationScope): Promise<CoordinationResult>;
 }
@@ -65,13 +65,13 @@ identity drift, cross-tenant observe/result lookup, and attempts to observe or
 receive a result for a handoff outside the originating tenant. The service exposes handoff, observe,
 and result only, and delegates delivery to an injected adapter.
 
-M4 ships a native in-process `InMemoryMosCoordinationPort` as the concrete,
+M4 ships a native in-process `InMemoryInteractionCoordinationPort` as the concrete,
 deterministic adapter. It preserves the immutable handoff ID, tenant, requester
 identity, and correlation ID while demonstrating the handoff → observe → result
 round trip. It is a queue/port adapter, not a Mos-side consumer.
 
 A future fleet/tmux adapter is a documented M5 deployment seam and must
-implement the same `MosCoordinationPort`; no channel client or interaction
+implement the same `InteractionCoordinationPort`; no channel client or interaction
 runtime calls a transport directly.
 
 ## Required tests

packages/mosaic/src/tui/gateway-api.interaction-errors.test.ts

@@ -11,7 +11,7 @@ const base = { agentName: 'Nova', correlationId: 'corr-1', sessionId: 'session-1
 
 afterEach(() => vi.unstubAllGlobals());
 
-/** The TUI must preserve gateway denial type/status rather than treating it as success. */
+/** Unit coverage: the TUI preserves a non-success gateway response in its CLI error. */
 describe('interaction gateway error mapping', (): void => {
   it.each([
     {
@@ -23,7 +23,7 @@ describe('interaction gateway error mapping', (): void => {
     },
     {
       name: 'send invalid request',
-      response: { status: 400, message: 'Content and idempotency key are required' },
+      response: { status: 403, message: 'Content and idempotency key are required' },
       invoke: (): Promise<unknown> =>
         sendInteractionMessage(gateway, cookie, {
           ...base,
@@ -31,7 +31,7 @@ describe('interaction gateway error mapping', (): void => {
           idempotencyKey: 'message-1',
         }),
       expected:
-        'Failed to send interaction message (400): {"message":"Content and idempotency key are required"}',
+        'Failed to send interaction message (403): {"message":"Content and idempotency key are required"}',
     },
     {
       name: 'stop forbidden',