fix(cursor): preserve bare client tool names for Claude Code sessions

[yeongjunyoo]

Summary

When Claude Code connects to OpenCodex via /v1/messages using a Cursor-backed model (e.g. ocx-claude-cursor--*), Claude Code advertises its standard bare client tools (Bash, Read, Write, Edit, Grep, Glob, Task, GetDynamicTools, etc.).

Previously, isCursorBareClientToolWireAliased unconditionally prefixed all non-proxy-owned bare tools with ocx_client_. This introduced two critical issues for Claude Code sessions:

1. Catalog/Prompt Contradiction: Claude Code's hardcoded system prompt expects tools named Bash, Read, Edit, etc. When OpenCodex renamed them to ocx_client_Bash, the model fell back to emitting Cursor-native execution frames (shellArgs, readArgs, etc.).
2. Prompt-Injection Trip / Stalling Refusal Loop: OpenCodex denied these native execution frames with cursorNativeExecRedirectHint, which contained "Re-issue this operation NOW through one of the tools: \ocx_client_`... Do NOT narrate this redirect, do NOT comment on tool availability...". Frontier Claude models flagged this unrecognized directive and unadvertised tool reference as an adversarial prompt-injection attack, refusing further execution and stalling the session with messages like "ocx_client_ 도구로 다시 시도하라는 안내가 나왔습니다"`.

Fix

• Defined CLAUDE_CLIENT_BARE_TOOL_NAMES and isClaudeClientBareToolName(name).
• Made bare client tool aliasing conditional on the presence of a bare Codex shell bridge (exec_command/shell_command) in the catalog:
  • When a Codex shell bridge is present (e.g. Codex Desktop), bare tools like Glob are aliased as ocx_client_Glob to prevent collision with Codex native tools (preserving existing Codex behavior).
  • When no Codex shell bridge is present (e.g. Claude Code sessions), Claude client bare tools preserve their wire names verbatim (Bash, Read, Write, Edit, etc.).
• Passed the turn's tool catalog to cursorToolWireName across tool definitions, guidance system notes, native exec redirect hints, live transport mapping, request building, and protobuf replay turns (conversationTurns -> toolCallStep).
• Suppressed unavailableNeighborAgentToolNames warnings in buildCursorToolGuidanceSystemNote when the catalog contains Claude bare tools without a Codex shell bridge, while preserving the warning for MCP-only catalogs.

Verification

• bun test tests/providers/cursor/cursor-tool-definitions.test.ts (51 passed, 0 failed — including unit tests for Claude Code client bare tool preservation, Codex shell bridge aliasing, MCP-only neighboring tool warnings, and response name mapping).
• bun test tests/providers/cursor/cursor-blob.test.ts (130 passed, 0 failed — including catalog-aware replay tool wire naming test).
• bun test tests/providers/cursor/cursor-native-exec-policy.test.ts (39 passed, 0 failed).
• bun test tests/providers/cursor/cursor-native-exec.test.ts (26 passed, 0 failed).
• bun test tests/providers/cursor/cursor-request-builder.test.ts (51 passed, 0 failed).
• bun test tests/providers/cursor/cursor-tool-choice.test.ts (7 passed, 0 failed).
• bun scripts/structure-ssot.ts (passed).
• Verified TypeScript compilation (tsc --noEmit) passes with zero errors on all modified files.

Checklist

• Scope stays focused and avoids unrelated cleanup.
• Docs or release notes were updated when needed.
• Security-sensitive changes were reviewed for secrets, auth, and unsafe defaults.

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Summary by CodeRabbit

• New Features
  • Claude Code client tools retain their familiar names in Cursor when no Codex shell bridge is available. When a bridge is present, names are aliased to avoid conflicts.
  • Tool choices, calls, and replayed conversations now resolve names against the available tool catalog. Tool-size limits account for aliased names.
• Documentation
  • Added guidance on client tools in Cursor, including naming and transport limits.
• Tests
  • Added coverage for tool naming, replay, selection, and byte-budget boundaries.

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📝 Walkthrough

Walkthrough

Cursor tool naming now uses the advertised catalog to determine when Claude client tools receive wire aliases. Registration, guidance, redirects, request construction, and protobuf replay pass catalog context to name resolution. Tool-choice matching and transport-size accounting also use that context.

Changes

Cursor tool naming

Layer / File(s)	Summary
Catalog-aware wire-name rules src/adapters/cursor/tool-naming.ts, src/adapters/cursor/tool-definitions.ts	The naming helpers recognize listed Claude bare tool names and alias them when the catalog contains a bare Codex shell bridge. Tool-choice matching, definition building, and encoded-size calculations use catalog context.
Apply catalog-aware names across Cursor paths src/adapters/cursor/live-transport.ts, src/adapters/cursor/native-exec.ts, src/adapters/cursor/tool-guidance.ts, src/adapters/cursor/protobuf-request.ts, tests/providers/cursor/cursor-tool-definitions.test.ts, docs-site/src/content/docs/guides/claude-code.md	Registration, redirects, guidance, and protobuf serialization pass the tool catalog to wire-name resolution. Tests cover naming and response mapping with and without a bare Codex shell bridge. The Claude Code guide describes catalog-dependent naming.
Resolve choices and account for wire-name bytes src/adapters/cursor/request-builder.ts, src/adapters/cursor/tool-definitions.ts, tests/providers/cursor/cursor-blob-claude-client-tools.test.ts, structure/providers/cursor.md, scripts/test-layout/layout.json, tests/fixtures/test-layout-expected.json	Request construction resolves accepted wire aliases against the original catalog before filtering, then uses the resolved choice in the request. Tool admission, eviction, and size estimates use catalog-aware names. Tests cover tool choices and byte limits. Provider documentation and test-layout mappings are updated.

Priority: ➖ Normal

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

Change: Bug fix

Sequence Diagram(s)

sequenceDiagram
  participant CursorRequestBuilder
  participant CursorToolDefinitions
  participant CursorToolWireName
  CursorRequestBuilder->>CursorToolDefinitions: Build definitions with catalog and tool choice
  CursorToolDefinitions->>CursorToolWireName: Resolve tool names using catalog
  CursorToolWireName-->>CursorToolDefinitions: Return bare or aliased wire names
  CursorToolDefinitions-->>CursorRequestBuilder: Return definitions and encoded sizes

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Merge Risk: ⚪ Minimal · up to c5d80

No actionable correctness, security, integrity, or availability risk remains from the reviewed changes.

Architecture Summary

Architecture risk: 🟡 Medium · up to 288cf

The change affects 2 systems.

Changed systems: src, tests

Architecture concerns
No architecture-level concerns identified.

Review details

Systems and components

• observed — src (service) was modified; 7 changed files map to changed impact.
• observed — tests (service) was modified; 2 changed files map to changed impact.

Before / after behavior

• observed — Modified behavior in src/adapters/cursor/live-transport.ts: The structured-edit tool-name mapping now passes cursorVisibleTools to cursorToolWireName when resolving each tool’s wire name.
• observed — Modified behavior in src/adapters/cursor/live-transport.ts: The schema and name-map loop now passes the full cursorVisibleTools set to cursorToolWireName when resolving each tool’s wire name.
• observed — Modified behavior in src/adapters/cursor/native-exec.ts: Client tool names are now generated with the full client-tool list supplied to cursorToolWireName, replacing the single-argument mapping.
• observed — Modified behavior in src/adapters/cursor/request-builder.ts: catalogLimitNote now resolves kept and omitted tool wire names against the full kept-tool catalog instead of calling the resolver without catalog context or passing it directly as a mapping callback.

Reliability and maintainability

• inferred — Risk-relevant change factors for src: blast_radius_1; direct_dependents_1

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 31.58% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 19 functions across 10 files. (1 skipped:…	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 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.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: preserving bare client tool names for Claude Code sessions on Cursor routes.

Full details: Docstring Coverage

Explanation

Docstring coverage is 31.58% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 19 functions across 10 files. (1 skipped: 1 unsupported.)

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Actionable comments posted: 5

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Inline comments:
Review comments at @src/adapters/cursor/tool-guidance.ts:
- Around line 132-137: Update unavailableNeighborAgentToolNames so MCP-only
catalogs retain the unavailable-neighbor warning; restrict the early return to
catalogs that contain Claude-style bare tools, using isClaudeClientBareToolName
from ./tool-naming. Add an MCP-only catalog test that verifies the warning is
preserved.

Review comments at @src/adapters/cursor/tool-naming.ts:
- Around line 203-205: Remove the broad uppercase-name regex from
isClaudeClientBareToolName and rely only on
CLAUDE_CLIENT_BARE_TOOL_NAMES.has(name), so unlisted names such as LS are not
treated as Claude bare tool names.
- Around line 212-216: Pass the request’s visible tool catalog through
conversationTurns to toolCallStep and into cursorToolWireName so replayed calls
use the same wire name as the advertised tool definition. Add a regression test
with exec_command and Read in the catalog, verifying replay uses ocx_client_Read
and both bare and prefixed response names map back to Read.

Review comments at @tests/providers/cursor/cursor-tool-definitions.test.ts:
- Around line 856-861: Update the `buildCursorToolGuidanceSystemNote` test to
assert the returned note is defined, then run both content checks
unconditionally; remove the `if (note)` guard so an undefined result fails the
test.
- Around line 864-881: Extend the test “aliases client tools when Codex shell
bridge is present in catalog” to call buildCursorToolGuidanceSystemNote with
toolsWithBridge and assert the note includes both aliased client tool names and
the neighboring-agent tool names warning.

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ℹ️ Review info

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• Configuration used: Repository: lidge-jun/opencodex/.coderabbit.yaml
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• Run ID: 24ea37a8-722d-4053-b83d-58b42ae1dbf4

📥 Commits

Reviewing files that changed from the base of the PR and between 7e7468a and db0bdc1.

📒 Files selected for processing (7)

• src/adapters/cursor/live-transport.ts
• src/adapters/cursor/native-exec.ts
• src/adapters/cursor/request-builder.ts
• src/adapters/cursor/tool-definitions.ts
• src/adapters/cursor/tool-guidance.ts
• src/adapters/cursor/tool-naming.ts
• tests/providers/cursor/cursor-tool-definitions.test.ts

Included review availability: This review used your included allowance. Your plan provides up to 10 included reviews per hour; 9 remain after this review.

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[lidge-jun]

Maintainer lane note (compat hardening sweep, lane B). Original change by @yeongjunyoo; maintainer repairs pushed to this branch (no force-push).

The PR had never run Cross-platform CI (fork approval). After merging dev, review and typecheck found four defects in the head, now fixed on this branch:

• d4bda6eff5 imports OcxTool; the new catalog-aware signatures in protobuf-request.ts did not typecheck.
• cc1c962891 moves the added replay case byte-for-byte into tests/providers/cursor/cursor-blob-claude-client-tools.test.ts (registered in both layout inventories), returning cursor-blob.test.ts to its 3,657-line cap.
• 6d83a52b50 sizes each tool with the same catalog-dependent wire name the final catalog uses (admission and eviction). Before the fix, exec_command plus a large Read measured 120,000 bytes but serialized as 120,022 because Read became ocx_client_Read. Documents the naming rule in structure/providers/cursor.md and guides/claude-code.md.
• 91d6925097 resolves forced tool_choice and allowed_tools entries against the original catalog before filtering, so choosing ocx_client_Read (or Read) still registers the tool after the bridge is filtered out; on the earlier head the definitions came out empty. Same-named remote tools are not admitted by a bare alias.
• c5d8043fd6 merges current dev (fix(messages): accumulate temporary tool declarations linearly #6656, fix(claude): retain ToolSearch references in translated results #6660, fix(jev): exclude Claude Code reminders from decision state #6662 and others). The guides/claude-code.md additions from fix(claude): retain ToolSearch references in translated results #6660 and this PR are separate sections and both stay accurate.

Verification on c5d8043fd6: bun test ./tests/providers/cursor plus the ToolSearch reference, ratchet and both layout guards 1,458 pass / 0 fail; bun run typecheck and bun run structure:check exit 0; layout.json stays at 1,999 lines. Independent adversarial review (gpt-6.1-sol), three rounds: final PASS. The full local suite was not run (parallel lanes share the machine). Hosted Cross-platform CI run 37474174348 completed success on this exact head; macOS, Windows and desktop jobs were skipped by their path filters.

#6664 overlaps these files and is prepared to land after this one.

[lidge-jun]

Maintainer integration into dev (MAINTAINERS.md dev-only maintainer integration; not a self-approval or an independent review).

• Exact head: c5d8043fd6f30e33256c236da96724813d930664
• Hosted CI on that head: all 30 latest check runs completed and every applicable one succeeded. Skipped jobs are gated off by their own path/event conditions.
• dev is two commits ahead (fix(devin): accumulate consecutive tool results without prefix copies #6657, fix(openai-chat): apply the Qwen3.8-27B template rule to gateway-namespaced ids #6685); neither touches a file this PR changes, and the merge tree is clean with scripts/test-layout/layout.json at 1999 lines.
• Review: independent gpt-6.1-sol reviews in the compat sweep lane (three rounds, final PASS); no unresolved review threads, no maintainer change requests. The draft state comes from the contributor readiness gate resetting after the lane's maintainer push, not from an open finding.
• Scope: Cursor adapter keeps bare client tool names for Claude Code sessions; no gui/ paths.
• Full local suite not run (parallel lanes share one machine); focused tests and typecheck ran in the lane, remaining coverage is the hosted matrix above.