Stop repetitive reasoning streams before provider timeout by PierrunoYT · Pull Request #1904 · Zoo-Code-Org/Zoo-Code

PierrunoYT · 2026-10-04T15:26:53Z

Summary

Detect sustained exact repetition in streamed reasoning and cancel the request.
Require explicit user confirmation before retrying the same request.
Forward OpenRouter abort signals to the OpenAI SDK so cancellation reaches the upstream inference request.

Scope and limitation

This mitigates the failure rather than fixing the model's reasoning. DeepSeek V4.1 Flash may still begin hallucinating on very large subtasks (observed beyond roughly 200k tokens), but Zoo Code now detects the repetitive reasoning, terminates the upstream request promptly, and avoids waiting roughly 1,500 seconds for the router timeout.

Regression coverage

Reproduces the reported DeepSeek-style reasoning loop across arbitrary chunk boundaries.
Verifies ordinary long reasoning and short repeated phrases are not flagged.
Verifies task cancellation without automatic retry.
Verifies OpenRouter receives the abort signal.

Verification

pnpm --dir src exec vitest run core/task/__tests__/ReasoningLoopDetector.spec.ts core/task/__tests__/Task.spec.ts api/providers/__tests__/openrouter.spec.ts — 185 tests passed.
pnpm lint — 11 packages passed (pre-commit hook).
pnpm check-types — 11 packages passed (pre-push hook).

Amp-Thread-ID: https://ampcode.com/threads/T-01a1077e-5823-744c-ad1a-1653a3ccdac5

coderabbitai · 2026-10-04T15:27:01Z

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📥 Commits

Reviewing files that changed from the base of the PR and between 280b240 and 3bc9597.

📒 Files selected for processing (3)

src/api/providers/__tests__/openrouter.spec.ts
src/core/task/Task.ts
src/core/task/__tests__/Task.spec.ts

📝 Summary

Summary by CodeRabbit

Bug Fixes
- OpenRouter streaming requests now honor cancellation signals, allowing in-progress requests to be stopped.
- Repetitive reasoning loops are detected and cancelled. You’re asked whether to retry instead of the task retrying automatically.

Walkthrough

The changes forward abort signals to OpenRouter streaming requests and add repetitive-reasoning detection to task streams. When the detector finds a repeated pattern, the task cancels the request and prompts the user instead of retrying automatically.

Changes

OpenRouter request cancellation

Layer / File(s)	Summary
Forward OpenRouter abort signals `src/api/providers/openrouter.ts`, `src/api/providers/__tests__/openrouter.spec.ts`	Streaming request options now include the supplied abort signal. A test checks that the SDK receives the same signal. The Anthropic beta header remains limited to Anthropic models.

Repetitive reasoning detection

Layer / File(s)	Summary
Detect repeated reasoning `src/core/task/ReasoningLoopDetector.ts`, `src/core/task/__tests__/ReasoningLoopDetector.spec.ts`	The detector checks bounded reasoning text for repeated patterns and returns whether it found a match. Tests cover repeated cycles and distinct reasoning steps.
Cancel and prompt on detected loops `src/core/task/Task.ts`, `src/core/task/__tests__/Task.spec.ts`	Task checks reasoning chunks and cancels the request when a loop is detected. The retry path prompts the user for this error instead of retrying automatically. A test checks cancellation and prompting.

Priority: ➖ Normal

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Bug fix

Sequence Diagram(s)

sequenceDiagram
  participant Task
  participant ReasoningLoopDetector
  participant Request
  participant User
  Task->>ReasoningLoopDetector: Check reasoning chunk
  ReasoningLoopDetector-->>Task: Report repeated pattern
  Task->>Request: Cancel current request
  Task->>User: Prompt with RepetitiveReasoningError

Merge Risk: 🟡 Moderate · up to 280b2

Detection of repetitive reasoning can be delayed when the provider stalls, which undermines the timeout mitigation. Retrying after a detected loop duplicates the user's message in the conversation history. Fix both before merging.

Security Architecture Review

Security architecture risk: 🔵 Low · up to 280b2

Cancellation improves containment of repetitive requests, but confirmed retries can duplicate conversation history. End-to-end interruption and confirmation enforcement are not fully established.

Retained concerns

Low · reliability · inferred: Confirmed retry after repetitive-reasoning cancellation requeues non-empty user content with retryAttempt zero while retaining the original user turn. The next attempt therefore appends that content again, violating recovery-history idempotency and changing the conversation supplied to subsequent requests. This extends a pre-existing output-token retry behavior to the newly introduced cancellation path; it does not establish unauthorized tool execution.

Security review details

Security Blast Radius

inferred — The demonstrated exposure is the active task's inference request and conversation history. Provider output can trigger cancellation and retry handling, but the inspected changes do not add a route to another tenant, credential store, or privileged service. The supplied dependency evidence does not establish broader exposure.

Security Findings and Attack Paths

inferred — Repeated provider reasoning followed by an accepted retry can cause duplicate user history through the newly reachable recovery branch. The source supports a conversation-integrity defect, not a verified privilege-escalation or tool-replay attack.

Trust Boundaries and Controls

observed — Task owns the abort controller and passes its signal through request metadata; OpenRouter now forwards that signal into SDK options. Tool selection remains on the existing metadata path, and the existing stream consumer interrupts after a completed tool-use result. These controls are counterevidence to an asserted new tool-authority expansion.

Resilience and Maintainability Implications

observed — Error handling saves partial UI state and clears streaming/controller state in finally. The cancellation regression uses a mocked declined prompt, and the provider regression verifies signal forwarding into a mocked SDK call. Neither establishes real approval-policy behavior or live upstream termination.

Hardening Proposals

proposed — Make confirmed recovery preserve the original history turn, evaluate repetition before another blocking read, and validate confirmation policy and provider termination through the real cancellation path. These are containment and recovery improvements, not additional verified security findings.

🚥 Pre-merge checks | ✅ 7 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Regression Evidence	⚠️ Warning	The new OpenRouter abort-signal test uses `mockOptions`, whose model is `anthropic/claude-sonnet-4`. It only verifies the combined Anthropic-header and abort-signal case. The changed `openrouter.ts` c…	Add a focused `OpenRouterHandler.createMessage` test using a non-Anthropic model and `metadata.abortSignal`. Assert that the OpenAI SDK receives that signal and does not receive the Anthropic beta header.

✅ Passed checks (7 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Security Boundaries	✅ Passed	No changed path meets the security failure conditions. The new detector compares streamed reasoning as text and raises a fixed error; it does not execute or use that text to authorize actions. OpenRou…
Persistence Integrity	✅ Passed	No changed persistence path meets the failure condition. The pull request adds only in-memory loop detection, request cancellation, and OpenRouter request options. When the new `RepetitiveReasoningErr…
Lifecycle Resource Cleanup	✅ Passed	No changed lifecycle path leaves a resource active or duplicates work. `ReasoningLoopDetector` is scoped to one request and keeps a bounded buffer. When it detects repetition, `Task` aborts the reques…
Title check	✅ Passed	The title clearly summarizes the main change: stopping repetitive reasoning streams before provider timeouts.
Description check	✅ Passed	The description explains the implementation, scope, regression coverage, and verification. It does not include the required approved GitHub issue link.

Full details: Regression Evidence

Explanation

The new OpenRouter abort-signal test uses mockOptions, whose model is anthropic/claude-sonnet-4. It only verifies the combined Anthropic-header and abort-signal case. The changed openrouter.ts code also adds the separate non-Anthropic signal path, which is needed for models such as DeepSeek. No focused createMessage test covers that path, so a regression that forwards the signal only for Anthropic models would pass the new test.

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github-actions · 2026-10-04T15:27:17Z

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codecov · 2026-10-04T15:37:50Z

Codecov Report

❌ Patch coverage is 91.89189% with 3 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/core/task/ReasoningLoopDetector.ts	93.33%	1 Missing and 1 partial ⚠️
src/api/providers/openrouter.ts	66.66%	0 Missing and 1 partial ⚠️

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coderabbitai

Actionable comments posted: 3

🪄 Fix CodeRabbit comments on this PR

🤖 Prompt to fix review comments

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only still-valid issues, skip the rest with a brief reason, keep changes
minimal, and validate.

Inline comments:
Review comments at @src/core/task/__tests__/Task.spec.ts:
- Around line 606-609: Update the test around `recursivelyMakeClineRequests` so
the provider stream pauses on its next read after yielding a repetitive
reasoning chunk. Assert cancellation while that read is still pending, then
release it and await task completion; do not rely on `cancelSpy` being called
only after the task call completes.

Review comments at @src/core/task/Task.ts:
- Line 3730: Update the confirmed-retry handling for RepetitiveReasoningError in
Task.ts to increment retryAttempt when requeuing currentUserContent instead of
resetting it to 0. Preserve the existing retry limit behavior and add a test
covering a confirmed retry of a non-empty request to ensure its history is not
duplicated.
- Line 3317: Update the stream-processing flow around reasoningLoopDetector.add
so each current reasoning chunk is checked for a loop before awaiting the next
stream item; when detected, call cancelCurrentRequest() without waiting for
another chunk. Preserve the existing handling for chunks that do not trigger the
detector.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository: Zoo-Code-Org/Zoo-Code/.coderabbit.yaml
Review profile: ASSERTIVE
Plan: Advanced
Run ID: dbffe3fe-e24c-4130-9427-f404b653eda2

📥 Commits

Reviewing files that changed from the base of the PR and between 3859e5d and 280b240.

📒 Files selected for processing (6)

src/api/providers/__tests__/openrouter.spec.ts
src/api/providers/openrouter.ts
src/core/task/ReasoningLoopDetector.ts
src/core/task/Task.ts
src/core/task/__tests__/ReasoningLoopDetector.spec.ts
src/core/task/__tests__/Task.spec.ts

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📓 Path-based instructions (6)

Check persistence and lifecycle invariants: awaited atomic writes, rollback or explicit partial-failure behavior, cross-window state consistency, stale listeners/watchers, cancellation, idempotency, and safe restart/resume without lost or d...