YeonGyu-Kim 524edb2b2e fix: #164 Stage A — cooperative cancellation via cancel_event in submit_message
Closes the #161 follow-up gap identified in review: wall-clock timeout
bounded caller-facing wait but did not cancel the underlying provider
thread, which could silently mutate mutable_messages / transcript_store /
permission_denials / total_usage after the caller had already observed
stop_reason='timeout'. A ghost turn committed post-deadline would poison
any session that got persisted afterwards.

Stage A scope (this commit): runtime + engine layer cooperative cancel.

Engine layer (src/query_engine.py):
- submit_message now accepts cancel_event: threading.Event | None = None
- Two safe checkpoints:
  1. Entry (before max_turns / budget projection) — earliest possible return
  2. Post-budget (after output synthesis, before mutation) — catches cancel
     that arrives while output was being computed
- Both checkpoints return stop_reason='cancelled' with state UNCHANGED
  (mutable_messages, transcript_store, permission_denials, total_usage
  all preserved exactly as on entry)
- cancel_event=None preserves legacy behaviour with zero overhead (no
  checkpoint checks at all)

Runtime layer (src/runtime.py):
- run_turn_loop creates one cancel_event per invocation when a deadline
  is in play (and None otherwise, preserving legacy fast path)
- Passes the same event to every submit_message call across turns, so a
  late cancel on turn N-1 affects turn N
- On timeout (either pre-call or mid-call), runtime explicitly calls
  cancel_event.set() before future.cancel() + synthesizing the timeout
  TurnResult. This upgrades #161's best-effort future.cancel() (which
  only cancels not-yet-started futures) to cooperative mid-flight cancel.

Stop reason taxonomy after Stage A:
  'completed'           — turn committed, state mutated exactly once
  'max_budget_reached'  — overflow, state unchanged (#162)
  'max_turns_reached'   — capacity exceeded, state unchanged
  'cancelled'           — cancel_event observed, state unchanged (#164 Stage A)
  'timeout'             — synthesised by runtime, not engine (#161)

The 'cancelled' vs 'timeout' split matters:
- 'timeout' is the runtime's best-effort signal to the caller: deadline hit
- 'cancelled' is the engine's confirmation: cancel was observed + honoured

If the provider call wedges entirely (never reaches a checkpoint), the
caller still sees 'timeout' and the thread is leaked — but any NEXT
submit_message call on the same engine observes the event at entry and
returns 'cancelled' immediately, preventing ghost-turn accumulation.
This is the honest cooperative limit in Python threading land; true
preemption requires async-native provider IO (future work, not Stage A).

Tests (29 new tests, tests/test_submit_message_cancellation.py + tests/
test_run_turn_loop_cancellation.py):

Engine-layer (12 tests):
- TestCancellationBeforeCall (5): pre-set event returns 'cancelled' immediately;
  mutable_messages, transcript_store, usage, permission_denials all preserved
- TestCancellationAfterBudgetCheck (1): cancel set mid-call (after projection,
  before commit) still honoured; output synthesised but state untouched
- TestCancellationAfterCommit (2): post-commit cancel not observable (honest
  limit) BUT next call on same engine observes it + returns 'cancelled'
- TestLegacyCallersUnchanged (3): cancel_event=None preserves #162 atomicity
  + max_turns contract with zero behaviour change
- TestCancellationVsOtherStopReasons (2): cancel precedes max_turns check;
  cancel does not retroactively override a completed turn

Runtime-layer (5 tests):
- TestTimeoutPropagatesCancelEvent (3): submit_message receives a real Event
  object when deadline is set; None in legacy mode; timeout actually calls
  event.set() so in-flight threads observe at their next checkpoint
- TestCancelEventSharedAcrossTurns (1): same event object passed to every
  turn (object identity check) — late cancel on turn N-1 must affect turn N

Regression: 3 existing timeout test mocks updated to accept cancel_event
kwarg (mocks that previously had signature (prompt, commands, tools, denials)
now have (prompt, commands, tools, denials, cancel_event=None) since runtime
passes cancel_event positionally on the timeout path).

Full suite: 97 → 114 passing, zero regression.

Closes ROADMAP #164 Stage A.

What's explicitly NOT in Stage A:
- Preemptive cancellation of wedged provider IO (requires asyncio-native
  provider path; larger refactor)
- Timeout on the legacy unbounded run_turn_loop path (by design: legacy
  callers opt out of cancellation entirely)
- CLI exposure of 'cancelled' as a distinct exit code (currently 'cancelled'
  maps to the same stop_reason != 'completed' break condition as others;
  CLI surface for cancel is a separate pinpoint if warranted)
2026-04-22 18:14:14 +09:00
2026-04-07 15:52:30 +09:00

Claw Code

ultraworkers/claw-code · Usage · Rust workspace · Parity · Roadmap · UltraWorkers Discord

Star history for ultraworkers/claw-code

Claw Code

Claw Code is the public Rust implementation of the claw CLI agent harness. The canonical implementation lives in rust/, and the current source of truth for this repository is ultraworkers/claw-code.

Important

Start with USAGE.md for build, auth, CLI, session, and parity-harness workflows. Make claw doctor your first health check after building, use rust/README.md for crate-level details, read PARITY.md for the current Rust-port checkpoint, and see docs/container.md for the container-first workflow.

ACP / Zed status: claw-code does not ship an ACP/Zed daemon entrypoint yet. Run claw acp (or claw --acp) for the current status instead of guessing from source layout; claw acp serve is currently a discoverability alias only, and real ACP support remains tracked separately in ROADMAP.md.

Current repository shape

  • rust/ — canonical Rust workspace and the claw CLI binary
  • USAGE.md — task-oriented usage guide for the current product surface
  • PARITY.md — Rust-port parity status and migration notes
  • ROADMAP.md — active roadmap and cleanup backlog
  • PHILOSOPHY.md — project intent and system-design framing
  • src/ + tests/ — companion Python/reference workspace and audit helpers; not the primary runtime surface

Quick start

Note

[!WARNING] cargo install claw-code installs the wrong thing. The claw-code crate on crates.io is a deprecated stub that places claw-code-deprecated.exe — not claw. Running it only prints "claw-code has been renamed to agent-code". Do not use cargo install claw-code. Either build from source (this repo) or install the upstream binary:

cargo install agent-code   # upstream binary — installs 'agent.exe' (Windows) / 'agent' (Unix), NOT 'agent-code'

This repo (ultraworkers/claw-code) is build-from-source only — follow the steps below.

# 1. Clone and build
git clone https://github.com/ultraworkers/claw-code
cd claw-code/rust
cargo build --workspace

# 2. Set your API key (Anthropic API key — not a Claude subscription)
export ANTHROPIC_API_KEY="sk-ant-..."

# 3. Verify everything is wired correctly
./target/debug/claw doctor

# 4. Run a prompt
./target/debug/claw prompt "say hello"

Note

Windows (PowerShell): the binary is claw.exe, not claw. Use .\target\debug\claw.exe or run cargo run -- prompt "say hello" to skip the path lookup.

Windows setup

PowerShell is a supported Windows path. Use whichever shell works for you. The common onboarding issues on Windows are:

  1. Install Rust first — download from https://rustup.rs/ and run the installer. Close and reopen your terminal when it finishes.
  2. Verify Rust is on PATH:
    cargo --version
    
    If this fails, reopen your terminal or run the PATH setup from the Rust installer output, then retry.
  3. Clone and build (works in PowerShell, Git Bash, or WSL):
    git clone https://github.com/ultraworkers/claw-code
    cd claw-code/rust
    cargo build --workspace
    
  4. Run (PowerShell — note .exe and backslash):
    $env:ANTHROPIC_API_KEY = "sk-ant-..."
    .\target\debug\claw.exe prompt "say hello"
    

Git Bash / WSL are optional alternatives, not requirements. If you prefer bash-style paths (/c/Users/you/... instead of C:\Users\you\...), Git Bash (ships with Git for Windows) works well. In Git Bash, the MINGW64 prompt is expected and normal — not a broken install.

Post-build: locate the binary and verify

After running cargo build --workspace, the claw binary is built but not automatically installed to your system. Here's where to find it and how to verify the build succeeded.

Binary location

After cargo build --workspace in claw-code/rust/:

Debug build (default, faster compile):

  • macOS/Linux: rust/target/debug/claw
  • Windows: rust/target/debug/claw.exe

Release build (optimized, slower compile):

  • macOS/Linux: rust/target/release/claw
  • Windows: rust/target/release/claw.exe

If you ran cargo build without --release, the binary is in the debug/ folder.

Verify the build succeeded

Test the binary directly using its path:

# macOS/Linux (debug build)
./rust/target/debug/claw --help
./rust/target/debug/claw doctor

# Windows PowerShell (debug build)
.\rust\target\debug\claw.exe --help
.\rust\target\debug\claw.exe doctor

If these commands succeed, the build is working. claw doctor is your first health check — it validates your API key, model access, and tool configuration.

Optional: Add to PATH

If you want to run claw from any directory without the full path, choose one of these approaches:

Option 1: Symlink (macOS/Linux)

ln -s $(pwd)/rust/target/debug/claw /usr/local/bin/claw

Then reload your shell and test:

claw --help

Option 2: Use cargo install (all platforms)

Build and install to Cargo's default location (~/.cargo/bin/, which is usually on PATH):

# From the claw-code/rust/ directory
cargo install --path . --force

# Then from anywhere
claw --help

Option 3: Update shell profile (bash/zsh)

Add this line to ~/.bashrc or ~/.zshrc:

export PATH="$(pwd)/rust/target/debug:$PATH"

Reload your shell:

source ~/.bashrc  # or source ~/.zshrc
claw --help

Troubleshooting

  • "command not found: claw" — The binary is in rust/target/debug/claw, but it's not on your PATH. Use the full path ./rust/target/debug/claw or symlink/install as above.
  • "permission denied" — On macOS/Linux, you may need chmod +x rust/target/debug/claw if the executable bit isn't set (rare).
  • Debug vs. release — If the build is slow, you're in debug mode (default). Add --release to cargo build for faster runtime, but the build itself will take 510 minutes.

Note

Auth: claw requires an API key (ANTHROPIC_API_KEY, OPENAI_API_KEY, etc.) — Claude subscription login is not a supported auth path.

Run the workspace test suite after verifying the binary works:

cd rust
cargo test --workspace

Documentation map

Ecosystem

Claw Code is built in the open alongside the broader UltraWorkers toolchain:

Ownership / affiliation disclaimer

  • This repository does not claim ownership of the original Claude Code source material.
  • This repository is not affiliated with, endorsed by, or maintained by Anthropic.
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