Commit a5bbad910f78cc14eef8baa94fe6f46676f78d5a | the-knife

author	Darahaas Yajamanyam <63366288+darahaas15@users.noreply.github.com> 2026-09-05 05:51:15+05:30
committer	GitHub <noreply@github.com> 2026-09-04 17:21:15-07:00
log	a5bbad910f78cc14eef8baa94fe6f46676f78d5a
tree	84c2bc630ce58cd7c6d7adbf6e29e2cb0aa6e297
parent	1963ca0abe07f9b9aac67820bca45ea3b46ce023
signature	Signed by PGP key B5690EEEBB952194

fix(server): surface Claude safety model fallback notices instead of dropping them (#8853)

Co-authored-by: Julius Marminge <51714798+juliusmarminge@users.noreply.github.com>

2 files changed, 34 insertions(+), 10 deletions(-)

apps
- server
  - src
    provider
    Layers
    ClaudeAdapter.test.ts
    ClaudeAdapter.ts

apps/server/src/provider/Layers/ClaudeAdapter.test.ts+26-9

 @@ -3449,10 +3449,14 @@ describe("ClaudeAdapterLive", () => {
     const harness = makeHarness();
     return Effect.gen(function* () {
       const adapter = yield* ClaudeAdapter;
-      const runtimeEvents: Array<ProviderRuntimeEvent> = [];
+      const runtimeEventsFiber = yield* adapter.streamEvents.pipe(
-      const runtimeEventsFiber = yield* Stream.runForEach(adapter.streamEvents, (event) =>
+        Stream.takeUntil(
-        Effect.sync(() => runtimeEvents.push(event)),
+          (event) =>
-      ).pipe(Effect.forkChild);
+            event.type === "session.state.changed" && event.payload.reason === "api_retry:3/10",
+        ),
+        Stream.runCollect,
+        Effect.forkChild,
+      );
       yield* adapter.startSession({
         threadId: THREAD_ID,
 @@ -3498,7 +3502,6 @@ describe("ClaudeAdapterLive", () => {
           uuid: "tu",
         },
         { type: "system", subtype: "commands_changed", session_id: "session", uuid: "cc" },
-        { type: "system", subtype: "model_refusal_fallback", session_id: "session", uuid: "mrf" },
         { type: "system", subtype: "local_command_output", session_id: "session", uuid: "lco" },
         { type: "system", subtype: "plugin_install", session_id: "session", uuid: "pi" },
         { type: "system", subtype: "memory_recall", session_id: "session", uuid: "mr" },
 @@ -3545,6 +3548,21 @@ describe("ClaudeAdapterLive", () => {
       ]) {
         harness.query.emit(message as unknown as SDKMessage);
       }
+      // Safety model-fallback notices DO surface as a warning row.
+      harness.query.emit({
+        type: "system",
+        subtype: "model_refusal_fallback",
+        trigger: "refusal",
+        direction: "retry",
+        original_model: "claude-fable-5",
+        fallback_model: "claude-opus-4-8",
+        request_id: "req_test",
+        api_refusal_category: "cyber",
+        api_refusal_explanation: null,
+        content: "Safeguards flagged this message. Switched to Opus 4.8.",
+        session_id: "session",
+        uuid: "mrf",
+      } as unknown as SDKMessage);
       // High-priority notifications DO surface as a warning row.
       harness.query.emit({
         type: "system",
 @@ -3602,15 +3620,15 @@ describe("ClaudeAdapterLive", () => {
         session_id: "session",
         uuid: "retry",
       } as unknown as SDKMessage);
-      yield* Effect.yieldNow;
+      const runtimeEvents = Array.from(yield* Fiber.join(runtimeEventsFiber));
-      yield* Effect.yieldNow;
       const warnings = runtimeEvents.filter((event) => event.type === "runtime.warning");
-      // Exactly three warnings: the high-priority notification, the
+      // Exactly four warnings: the fallback notice, high-priority notification,
       // warning-level informational note, and the refusal. Nothing else.
       assert.deepEqual(
         warnings.map((event) => event.payload.message),
         [
+          "Safeguards flagged this message. Switched to Opus 4.8.",
           "context window nearly full",
           "Stop hook prevented continuation",
           "The request was declined by the API.",
 @@ -3638,7 +3656,6 @@ describe("ClaudeAdapterLive", () => {
           event.payload.reason.startsWith("api_retry:"),
       );
       assert.equal(heartbeat?.type, "session.state.changed");
-      runtimeEventsFiber.interruptUnsafe();
     }).pipe(
       Effect.provideService(Random.Random, makeDeterministicRandomService()),
       Effect.provide(harness.layer),

apps/server/src/provider/Layers/ClaudeAdapter.ts+8-1

 @@ -3655,6 +3655,14 @@ export const makeClaudeAdapter = Effect.fn("makeClaudeAdapter")(function* (
           yield* emitRuntimeWarning(context, message.text, message);
         }
         return;
+      case "model_refusal_fallback":
+        // A safety fallback switched the model mid-session (e.g. Fable 5
+        // retried on Opus 4.8 after a flagged request). The CLI ships the
+        // user-facing notice in `content`; surface it like high-priority
+        // notifications so the rest of the session isn't silently served
+        // by a different model.
+        yield* emitRuntimeWarning(context, message.content, message);
+        return;
       // Inner protocol/UX details with no T3 surface today — consumed
       // deliberately so they don't masquerade as unknown-subtype warnings.
       // `background_tasks_changed` is a roster snapshot ({tasks: [...]}); the
 @@ -3663,7 +3671,6 @@ export const makeClaudeAdapter = Effect.fn("makeClaudeAdapter")(function* (
       // source. `control_request_progress` is a liveness heartbeat for an
       // in-flight control request. `worker_shutting_down` is a Remote
       // Control worker notice; the session close path reports the outcome.
-      case "model_refusal_fallback":
       case "local_command_output":
       case "plugin_install":
       case "commands_changed":