fix: prevent duplicate diagnostic task creation

Serialize cross-parent diagnostic claims at project scope and reuse a recent active canonical task. Keep ordinary, completed, and path-distinct work independent.

.changeset/prevent-cross-parent-diagnostic-duplicates.md

@@ -0,0 +1,7 @@
+---
+"@runfusion/fusion": patch
+---
+
+summary: Prevent agents from filing duplicate active diagnostic follow-ups discovered by different tasks.
+category: fix
+dev: Adds narrow code-identifier-based cross-parent deduplication while preserving distinct and completed work.

packages/core/src/__tests__/duplicate-intake.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it, vi } from "vitest";
 
-import { computeParentIntentClaimId, findSameAgentDuplicates, flagSameAgentDuplicate } from "../duplicate-intake.js";
+import { computeCrossParentDiagnosticClaimId, computeParentIntentClaimId, findSameAgentDuplicates, flagSameAgentDuplicate } from "../duplicate-intake.js";
 import type { TaskStore } from "../store.js";
 
 describe("findSameAgentDuplicates", () => {
@@ -122,6 +122,44 @@ describe("findSameAgentDuplicates", () => {
     expect(claim("Add new support")).toMatch(/^agent-parent-intent:FN-8277:[a-f0-9]{64}$/);
   });
 
+  it("derives one cross-parent claim for the recently repeated diagnostic", () => {
+    const descriptions = [
+      "Investigate and repair dashboard typecheck failure: app/utils/capture-screenshot.ts imports unresolved `html2canvas`, causing `pnpm verify:fast` to fail.",
+      "Fix dashboard typecheck failure: app/utils/capture-screenshot.ts cannot resolve the html2canvas module during pnpm verify:fast.",
+      "Fix dashboard typecheck failure: packages/dashboard/app/utils/capture-screenshot.ts imports unresolved html2canvas. Add or correctly wire the dependency.",
+      "Fix dashboard typecheck missing html2canvas dependency/import in packages/dashboard/app/utils/capture-screenshot.ts (TS2307 observed during pnpm verify:fast).",
+      "Fix dashboard typecheck dependency resolution for app/utils/capture-screenshot.ts: Cannot find module 'html2canvas' during pnpm verify:fast.",
+      "Restore the missing `html2canvas` dependency declaration/lock entry for dashboard screenshot capture so @fusion/dashboard typecheck passes.",
+    ];
+
+    const claims = descriptions.map((description) => computeCrossParentDiagnosticClaimId({ description }));
+
+    expect(new Set(claims).size).toBe(1);
+    expect(claims[0]).toMatch(/^agent-diagnostic-intent:/);
+  });
+
+  it("does not globally claim ordinary work or unrelated work on the same module", () => {
+    expect(computeCrossParentDiagnosticClaimId({
+      description: "Add screenshot upload support using html2canvas",
+    })).toBeNull();
+    expect(computeCrossParentDiagnosticClaimId({
+      description: "Improve html2canvas capture performance",
+    })).toBeNull();
+  });
+
+  it("keeps diagnostic paths distinct when they share a basename", () => {
+    const first = computeCrossParentDiagnosticClaimId({
+      description: "Fix unresolved packages/alpha/index.ts typecheck failure.",
+    });
+    const second = computeCrossParentDiagnosticClaimId({
+      description: "Fix unresolved packages/beta/index.ts typecheck failure.",
+    });
+
+    expect(first).not.toBeNull();
+    expect(second).not.toBeNull();
+    expect(first).not.toBe(second);
+  });
+
   it("does not match sibling with different parent task", () => {
     const matches = findSameAgentDuplicates(
       {

packages/core/src/duplicate-intake.ts

@@ -78,6 +78,49 @@ export function computeParentIntentClaimId(input: SameAgentDuplicateInput): stri
   return parentId && anchor ? `agent-parent-intent:${parentId}:${anchor}` : null;
 }
 
+const DIAGNOSTIC_ACTION_PATTERN = /\b(?:fix|investigate|repair|resolve|restore)\b/i;
+const DIAGNOSTIC_FAILURE_PATTERN = /\b(?:cannot|can't|error|fail(?:ed|ure|s)?|missing|ts\d{4}|typecheck|unresolved)\b/i;
+const DIAGNOSTIC_OBJECT_PATTERNS = [
+  /\b(?:missing|unresolved)\s+([`'"]?[@a-z0-9][@a-z0-9._/-]*[`'"]?)/gi,
+  /\b(?:cannot|can't)\s+(?:find|resolve)(?:\s+module)?\s+(?:the\s+)?([`'"]?[@a-z0-9][@a-z0-9._/-]*[`'"]?)/gi,
+];
+const IGNORED_DIAGNOSTIC_OBJECTS = new Set(["a", "an", "dependency", "module", "the", "type", "types"]);
+
+function normalizeDiagnosticObject(value: string): string | null {
+  const normalized = value.toLowerCase().replace(/^[`'"]+|[`'".,;:]+$/g, "");
+  if (!normalized || IGNORED_DIAGNOSTIC_OBJECTS.has(normalized)) {
+    return null;
+  }
+  // Only code-shaped objects are safe for global convergence. Generic prose
+  // such as "missing button" must remain scoped to its parent task.
+  return /[0-9@./_-]/.test(normalized) ? normalized : null;
+}
+
+/**
+ * Stable claim for an active diagnostic follow-up that may be discovered by
+ * several unrelated parent tasks. This is intentionally narrower than general
+ * near-duplicate matching: only repair-shaped failures with a code identifier
+ * can converge globally.
+ */
+export function computeCrossParentDiagnosticClaim(input: Pick<SameAgentDuplicateInput, "title" | "description">): { id: string; searchTerm: string } | null {
+  const text = `${input.title ?? ""}\n${input.description}`;
+  if (!DIAGNOSTIC_ACTION_PATTERN.test(text) || !DIAGNOSTIC_FAILURE_PATTERN.test(text)) return null;
+
+  const objects = DIAGNOSTIC_OBJECT_PATTERNS.flatMap((pattern) =>
+    [...text.matchAll(pattern)]
+      .map((match) => normalizeDiagnosticObject(match[1] ?? ""))
+      .filter((value): value is string => value !== null),
+  );
+  const diagnosticObject = [...new Set(objects)].sort()[0];
+  if (!diagnosticObject) return null;
+  const fingerprint = computeContentFingerprint({ title: "agent-diagnostic-intent", description: diagnosticObject });
+  return fingerprint ? { id: `agent-diagnostic-intent:${fingerprint}`, searchTerm: diagnosticObject } : null;
+}
+
+export function computeCrossParentDiagnosticClaimId(input: Pick<SameAgentDuplicateInput, "title" | "description">): string | null {
+  return computeCrossParentDiagnosticClaim(input)?.id ?? null;
+}
+
 /**
  * Find candidate tasks that look like duplicates spawned by the same caller.
  *

packages/core/src/index.gate.ts

@@ -725,6 +725,8 @@ export type { TaskDependencyMutation } from "./store.js";
 export {
   findSameAgentDuplicates,
   computeParentIntentClaimId,
+  computeCrossParentDiagnosticClaim,
+  computeCrossParentDiagnosticClaimId,
   archiveAsSameAgentDuplicate,
   flagSameAgentDuplicate,
   flagTriageDuplicate,

packages/core/src/index.ts

@@ -768,6 +768,8 @@ export type { TaskDependencyMutation } from "./store.js";
 export {
   findSameAgentDuplicates,
   computeParentIntentClaimId,
+  computeCrossParentDiagnosticClaim,
+  computeCrossParentDiagnosticClaimId,
   archiveAsSameAgentDuplicate,
   flagSameAgentDuplicate,
   flagTriageDuplicate,

packages/engine/src/__tests__/agent-tools-delegation.test.ts

@@ -14,6 +14,8 @@ function createMockAgentStore(overrides: Partial<AgentStore> = {}): AgentStore {
 function createMockTaskStore(overrides: Partial<TaskStore> = {}): TaskStore {
   return {
     getSettings: vi.fn().mockResolvedValue({ autoSummarizeTitles: false }),
+    getRootDir: vi.fn().mockReturnValue("/project"),
+    searchTasks: vi.fn().mockResolvedValue([]),
     findRecentTasksBySourceParentTaskId: vi.fn().mockResolvedValue([]),
     findRecentTasksByContentFingerprint: vi.fn().mockResolvedValue([]),
     updateTask: vi.fn(),
@@ -368,6 +370,92 @@ describe("createDelegateTaskTool", () => {
     expect(taskStore.moveTask).not.toHaveBeenCalled();
   });
 
+  it("reuses one active diagnostic follow-up across different parent tasks", async () => {
+    const tasks: Task[] = [];
+    vi.mocked(taskStore.searchTasks).mockImplementation(async () => tasks);
+    vi.mocked(taskStore.findRecentTasksBySourceParentTaskId).mockImplementation(async (parentId) =>
+      tasks.filter((task) => task.sourceParentTaskId === parentId),
+    );
+    vi.mocked(taskStore.createTask).mockImplementation(async (input) => {
+      await Promise.resolve();
+      const now = new Date().toISOString();
+      const created = {
+        id: `FN-${tasks.length + 1}`,
+        description: input.description,
+        dependencies: [],
+        column: "triage" as const,
+        sourceParentTaskId: input.source?.sourceParentTaskId,
+        steps: [],
+        currentStep: 0,
+        log: [],
+        createdAt: now,
+        updatedAt: now,
+      } as Task;
+      tasks.push(created);
+      return created;
+    });
+
+    const [first, replay] = await Promise.all([
+      createAgentTask(taskStore, {
+        description: "Investigate and repair dashboard typecheck failure: app/utils/capture-screenshot.ts imports unresolved `html2canvas`, causing `pnpm verify:fast` to fail.",
+      }, { sourceTaskId: "FN-8343", rootDir: "/worktrees/FN-8343" }),
+      createAgentTask(taskStore, {
+        description: "Restore the missing `html2canvas` dependency declaration/lock entry for dashboard screenshot capture so @fusion/dashboard typecheck passes.",
+      }, { sourceTaskId: "FN-8348", rootDir: "/worktrees/FN-8348" }),
+    ]);
+
+    expect(first.wasDuplicate).toBe(false);
+    expect(replay).toMatchObject({ wasDuplicate: true, task: { id: first.task.id } });
+    expect(tasks).toHaveLength(1);
+    expect(taskStore.createTask).toHaveBeenCalledWith(expect.objectContaining({
+      source: expect.objectContaining({
+        sourceMetadata: expect.objectContaining({
+          crossParentDiagnosticClaimId: expect.stringMatching(/^agent-diagnostic-intent:/),
+        }),
+      }),
+    }), expect.anything());
+  });
+
+  it("does not let a completed diagnostic suppress newly required work", async () => {
+    const completed = {
+      id: "FN-DONE",
+      description: "Fix unresolved `html2canvas` typecheck failure.",
+      dependencies: [],
+      column: "done" as const,
+      sourceParentTaskId: "FN-OLD-PARENT",
+      steps: [],
+      currentStep: 0,
+      log: [],
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    } as Task;
+    const created = {
+      ...completed,
+      id: "FN-NEW",
+      column: "triage" as const,
+      sourceParentTaskId: "FN-NEW-PARENT",
+    } as Task;
+    vi.mocked(taskStore.searchTasks).mockResolvedValue([completed]);
+    vi.mocked(taskStore.createTask).mockResolvedValue(created);
+
+    const result = await createAgentTask(taskStore, {
+      description: "Restore the missing html2canvas dependency so dashboard typecheck passes.",
+    }, { sourceTaskId: "FN-NEW-PARENT" });
+
+    expect(result).toEqual({ task: created, wasDuplicate: false });
+    expect(taskStore.createTask).toHaveBeenCalledOnce();
+  });
+
+  it("fails closed when cross-parent diagnostic lookup is unavailable", async () => {
+    vi.mocked(taskStore.searchTasks).mockRejectedValue(new Error("database unavailable"));
+
+    await expect(createAgentTask(taskStore, {
+      description: "Fix unresolved `html2canvas` typecheck failure.",
+    }, { sourceTaskId: "FN-PARENT" })).rejects.toThrow("Unable to verify cross-parent diagnostic task uniqueness");
+
+    expect(taskStore.createTask).not.toHaveBeenCalled();
+  });
+
   it("persists option-based parent provenance on the step-session fn_task_create surface", async () => {
     const tool = createTaskCreateTool(taskStore, undefined, { sourceTaskId: "FN-PARENT", sourceAgentId: "agent-worker" });
     await tool.execute("call-1", { description: "Capture optional report screenshots" }, undefined as any, undefined as any, undefined as any);

packages/engine/src/agent-tools.ts

@@ -16,7 +16,7 @@ import * as fusionCore from "@fusion/core";
 import type { AgentState, AgentCapability, AgentUpdateInput, AgentLogEntry, Artifact, ArtifactCreateInput, ArtifactWithTask, Task, TaskDocument, TaskDocumentCreateInput, TaskStore, RunMutationContext, MessageStore, Message, SourceType, Settings, ResearchRun, ResearchRunStatus, TaskCreateInput, ReflectionStore, ApprovalRequestStore, ProjectSettings, ChatStore, WorkflowSettingDefinition, GoalStatus, WorkflowIrNode } from "@fusion/core";
 import { listTraits, isBuiltinWorkflowId, AgentStore, validateColumnAgentBindings, ColumnAgentBindingError, stripApprovalBypassFlags, WorkflowSettingRejectionError, resolveEffectiveSettingsById, resolveWorkflowIrById, findOrphanedSettingValues, BUILTIN_WORKFLOW_SETTINGS, MAX_TASK_LIST_TEXT_CHARS, formatCurrentTaskLine, normalizeWorkflowIcon, parseWorkflowIr, WorkflowIrError, assertColumnTraitsValid, ColumnTraitValidationError } from "@fusion/core";
 import { promoteHeldTask } from "./hold-release.js";
-import { computeParentIntentClaimId, DASHBOARD_USER_ID, dailyMemoryPath, ensureOpenClawMemoryFiles, evaluateImplementationTaskBind, extractAgentProvisioningRequest, findSameAgentDuplicates, getMemoryBackendCapabilities, getProjectMemory, isEphemeralAgent, memoryLongTermPath, normalizeMessageParticipant, reconcileDeterministicDuplicate, resolveAgentProvisioningPolicy, resolveMemoryBackend, resolveResearchSettings, resolveTaskGithubTracking, runDeterministicDuplicateGuard, scheduleQmdProjectMemoryRefresh, searchProjectMemory, shouldSkipBackgroundQmdRefresh } from "@fusion/core";
+import { computeCrossParentDiagnosticClaim, computeCrossParentDiagnosticClaimId, computeParentIntentClaimId, DASHBOARD_USER_ID, dailyMemoryPath, ensureOpenClawMemoryFiles, evaluateImplementationTaskBind, extractAgentProvisioningRequest, findSameAgentDuplicates, getMemoryBackendCapabilities, getProjectMemory, isEphemeralAgent, memoryLongTermPath, normalizeMessageParticipant, reconcileDeterministicDuplicate, resolveAgentProvisioningPolicy, resolveMemoryBackend, resolveResearchSettings, resolveTaskGithubTracking, runDeterministicDuplicateGuard, scheduleQmdProjectMemoryRefresh, searchProjectMemory, shouldSkipBackgroundQmdRefresh } from "@fusion/core";
 import { ResearchOrchestrator } from "./research-orchestrator.js";
 import { ResearchProviderRegistry } from "./research/provider-registry.js";
 import { ResearchStepRunner } from "./research-step-runner.js";
@@ -975,6 +975,13 @@ export async function createAgentTask(
   const rootDir = options?.rootDir;
   const sourceParentTaskId = (input.source?.sourceParentTaskId ?? options?.sourceTaskId)?.trim().toUpperCase();
   const sourceAgentId = input.source?.sourceAgentId ?? options?.sourceAgentId;
+  const crossParentDiagnosticClaim = options?.bypassDuplicateCheck === true
+    ? null
+    : computeCrossParentDiagnosticClaim({ title: input.title, description: input.description });
+  const crossParentDiagnosticClaimId = crossParentDiagnosticClaim?.id ?? null;
+  const duplicateLockScope = crossParentDiagnosticClaimId
+    ? store.getRootDir?.() ?? rootDir ?? "agent-tools"
+    : rootDir ?? store.getRootDir?.() ?? "agent-tools";
   const effectiveSource = input.source || sourceParentTaskId || sourceAgentId
     ? {
         sourceType: input.source?.sourceType ?? "api" as const,
@@ -987,11 +994,11 @@ export async function createAgentTask(
     title: input.title,
     description: input.description,
   }, {
-    lockScope: rootDir ?? store.getRootDir?.() ?? "agent-tools",
+    lockScope: duplicateLockScope,
     bypass: options?.bypassDuplicateCheck === true,
     acknowledgedDuplicates: options?.acknowledgedDuplicates,
-    serializationKey: sourceParentTaskId ? `parent:${sourceParentTaskId}` : undefined,
-    sourceParentTaskId,
+    serializationKey: crossParentDiagnosticClaimId ?? (sourceParentTaskId ? `parent:${sourceParentTaskId}` : undefined),
+    sourceParentTaskId: crossParentDiagnosticClaimId ? null : sourceParentTaskId,
     logger: log,
   });
 
@@ -1003,6 +1010,35 @@ export async function createAgentTask(
       };
     }
 
+    if (crossParentDiagnosticClaim) {
+      try {
+        const acknowledged = new Set(options?.acknowledgedDuplicates ?? []);
+        const cutoffMs = Date.now() - 24 * 60 * 60 * 1000;
+        const candidates = (await store.searchTasks(crossParentDiagnosticClaim.searchTerm, {
+          slim: true,
+          includeArchived: false,
+        }))
+          .filter((candidate) => candidate.column !== "done" && candidate.column !== "archived")
+          .filter((candidate) => Date.parse(candidate.createdAt) >= cutoffMs)
+          .filter((candidate) => !acknowledged.has(candidate.id))
+          .filter((candidate) => computeCrossParentDiagnosticClaimId({
+            title: candidate.title,
+            description: candidate.description,
+          }) === crossParentDiagnosticClaimId)
+          .sort((left, right) => Date.parse(left.createdAt) - Date.parse(right.createdAt));
+        const canonical = candidates[0];
+        if (canonical) {
+          return { task: await carryCanonicalTaskRouting(store, canonical, input), wasDuplicate: true };
+        }
+      } catch (error) {
+        log.warn("Cross-parent diagnostic duplicate pre-check failed; aborting creation", {
+          crossParentDiagnosticClaimId,
+          error: error instanceof Error ? error.message : String(error),
+        });
+        throw new Error("Unable to verify cross-parent diagnostic task uniqueness", { cause: error });
+      }
+    }
+
     if (sourceParentTaskId && options?.bypassDuplicateCheck !== true) {
       try {
         const acknowledged = new Set(options?.acknowledgedDuplicates ?? []);
@@ -1037,6 +1073,7 @@ export async function createAgentTask(
     const sourceMetadata = {
       ...(effectiveSource?.sourceMetadata ?? {}),
       ...(guard.fingerprint ? { contentFingerprint: guard.fingerprint } : {}),
+      ...(crossParentDiagnosticClaimId ? { crossParentDiagnosticClaimId } : {}),
     };
     const nextSource = effectiveSource
       ? {