Merge pull request #1726 from plarson/fix/triage-spec-review-fallback

fix(triage): pass fallback model settings to spec review

.changeset/friendly-reviewers-fallback.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": patch
+---
+
+Pass project fallback model settings into triage spec reviewer sessions so global default overrides are honored during review.

packages/engine/src/__tests__/triage.test.ts

@@ -1010,6 +1010,67 @@ describe("fast-mode triage", () => {
     }
   });
 
+  it("threads global fallback model settings into spec reviewer sessions", async () => {
+    const rootDir = await createTriageFixtureRoot("fusion-triage-review-fallback-");
+    try {
+      const taskId = "FN-REVIEW-FALLBACK";
+      await mkdir(join(rootDir, ".fusion", "tasks", taskId), { recursive: true });
+      await writeFile(
+        join(rootDir, ".fusion", "tasks", taskId, "PROMPT.md"),
+        "# Task\n\n## Mission\n\nDo the work.\n\n## Steps\n\n### Step 0: Implement\n\nShip it.",
+      );
+      mockReviewStep.mockResolvedValue({ verdict: "APPROVE", review: "ok", summary: "ok" });
+
+      const store = createMockStore({
+        getTask: vi.fn().mockResolvedValue({ ...mockTaskDetail, id: taskId, comments: [] }),
+        getSettings: vi.fn().mockResolvedValue({
+          maxConcurrent: 2,
+          maxWorktrees: 4,
+          pollIntervalMs: 10000,
+          groupOverlappingFiles: false,
+          autoMerge: true,
+          defaultProvider: "anthropic",
+          defaultModelId: "claude-opus-4-8",
+          defaultProviderOverride: "openai-codex",
+          defaultModelIdOverride: "gpt-5.5",
+          fallbackProvider: "openai-codex",
+          fallbackModelId: "gpt-5.5",
+          memoryEnabled: false,
+          agentPrompts: { roleAssignments: { reviewer: "custom-reviewer" } },
+        } as Settings),
+      });
+      const processor = new TriageProcessor(store, rootDir);
+      const tool = (processor as any).createReviewSpecTool(
+        taskId,
+        `.fusion/tasks/${taskId}/PROMPT.md`,
+        { current: null },
+        { current: null },
+        { current: null },
+        { current: "" },
+        {},
+        false,
+      );
+
+      await tool.execute({});
+
+      const reviewOptions = mockReviewStep.mock.calls[0]?.[7];
+      expect(reviewOptions).toMatchObject({
+        projectDefaultOverrideProvider: "openai-codex",
+        projectDefaultOverrideModelId: "gpt-5.5",
+        fallbackProvider: "openai-codex",
+        fallbackModelId: "gpt-5.5",
+        agentPrompts: { roleAssignments: { reviewer: "custom-reviewer" } },
+      });
+      expect(reviewOptions.settings).toMatchObject({
+        memoryEnabled: false,
+        agentPrompts: { roleAssignments: { reviewer: "custom-reviewer" } },
+      });
+    } finally {
+      mockReviewStep.mockReset();
+      await cleanupTriageFixtureRoot(rootDir);
+    }
+  });
+
   it("passes post-session gate in fast mode after fn_review_spec auto-approval", async () => {
     const rootDir = await createTriageFixtureRoot("fusion-triage-fast-gate-");
     try {

packages/engine/src/triage.ts

@@ -1890,6 +1890,10 @@ export class TriageProcessor {
               // Project-level validator fallback
               projectValidatorFallbackProvider: currentSettings.validatorFallbackProvider,
               projectValidatorFallbackModelId: currentSettings.validatorFallbackModelId,
+              // FNXC:SpecReviewerFallback 2026-06-23-08:50:
+              // Spec review must inherit global/default fallback reviewer model settings when no validator-specific fallback is configured, plus the project settings/prompt payload that reviewer sessions use for memory and custom prompt behavior.
+              fallbackProvider: currentSettings.fallbackProvider,
+              fallbackModelId: currentSettings.fallbackModelId,
               // Global validator lane
               globalValidatorProvider: currentSettings.validatorGlobalProvider,
               globalValidatorModelId: currentSettings.validatorGlobalModelId,
@@ -1901,8 +1905,10 @@ export class TriageProcessor {
               taskId,
               task: currentDetail,
               userComments: currentUserComments.length > 0 ? currentUserComments : undefined,
+              agentPrompts: currentSettings.agentPrompts,
               agentStore: this.options.agentStore,
               rootDir,
+              settings: currentSettings,
               // Track the spec reviewer's session under this task so it's
               // disposed alongside the main triage session on global pause.
               onSessionCreated: (s) => this.registerSubagentSession(taskId, s),