6a16f0824d
Dogfooded 2026-04-18 on main HEAD eabd257 from /tmp/cdW2.
A .claw.json pointing at command='/does/not/exist' as an MCP server
cheerfully reports:
mcp show unreachable → found: true
mcp list → configured_servers: 1, status field absent
doctor → config: ok, MCP servers: 1, has_failures: false
The broken server is invisible until agent tries to call a tool
from it mid-turn — burning tokens on failed tool call and forcing
retry loop.
Trace:
main.rs:1701-1780 check_config_health counts via
runtime_config.mcp().servers().len()
No which(). No TcpStream::connect(). No filesystem touch.
render_doctor_report has 6 checks (auth/config/install_source/
workspace/sandbox/system). No check_mcp_health exists.
commands/src/lib.rs mcp list/show emit config-side repr only.
No status field, no reachable field, no startup_state.
runtime/mcp_stdio.rs HAS startup machinery with error types,
but only invoked at turn-execution time — too late for
preflight.
Roadmap prescribes this exact surface:
- Phase 1 §3.5 Boot preflight / doctor contract explicitly lists
'MCP config presence and server reachability expectations'
- Phase 2 §4 canonical lane event schema includes lane.ready
- Phase 4.4.4 event provenance / environment labeling
- Product Principle #5 'Partial success is first-class' —
'MCP startup can succeed for some servers and fail for
others, with structured degraded-mode reporting'
All four unimplementable without preflight + per-server status.
Fix shape (~110 lines):
- check_mcp_health: which(command) for stdio, 1s TcpStream
connect for http/sse. Aggregate ok/warn/fail with per-server
detail lines.
- mcp list/show: add status field
(configured/resolved/command_not_found/connect_refused/
startup_failed). --probe flag for deeper handshake.
- doctor top-level: degraded_mode: bool, startup_summary.
- Wire preflight into prompt/repl bootstrap; emit one-time
mcp_preflight event.
Joins unplumbed-subsystem cross-cluster (#78, #100, #102) —
subsystem exists, diagnostic surface JSON-invisible. Joins
truth-audit (#80-#84, #86, #87, #89, #100) — doctor: ok lies
when MCP broken.
Natural bundle: #78 + #96 + #100 + #102 unplumbed-surface
quartet. Also #100 + #102 as pure doctor-surface-coverage 2-way.
Filed in response to Clawhip pinpoint nudge 1494797126041862285
in #clawcode-building-in-public.
Claw Code
ultraworkers/claw-code · Usage · Rust workspace · Parity · Roadmap · UltraWorkers Discord
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.mdfor build, auth, CLI, session, and parity-harness workflows. Makeclaw doctoryour first health check after building, userust/README.mdfor crate-level details, readPARITY.mdfor the current Rust-port checkpoint, and seedocs/container.mdfor the container-first workflow.ACP / Zed status:
claw-codedoes not ship an ACP/Zed daemon entrypoint yet. Runclaw acp(orclaw --acp) for the current status instead of guessing from source layout;claw acp serveis currently a discoverability alias only, and real ACP support remains tracked separately inROADMAP.md.
Current repository shape
rust/— canonical Rust workspace and theclawCLI binaryUSAGE.md— task-oriented usage guide for the current product surfacePARITY.md— Rust-port parity status and migration notesROADMAP.md— active roadmap and cleanup backlogPHILOSOPHY.md— project intent and system-design framingsrc/+tests/— companion Python/reference workspace and audit helpers; not the primary runtime surface
Quick start
Note
[!WARNING]
cargo install claw-codeinstalls the wrong thing. Theclaw-codecrate on crates.io is a deprecated stub that placesclaw-code-deprecated.exe— notclaw. Running it only prints"claw-code has been renamed to agent-code". Do not usecargo 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, notclaw. Use.\target\debug\claw.exeor runcargo 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:
- Install Rust first — download from https://rustup.rs/ and run the installer. Close and reopen your terminal when it finishes.
- Verify Rust is on PATH:
If this fails, reopen your terminal or run the PATH setup from the Rust installer output, then retry.cargo --version - 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 - Run (PowerShell — note
.exeand 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.
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:
cd rust
cargo test --workspace
Documentation map
USAGE.md— quick commands, auth, sessions, config, parity harnessrust/README.md— crate map, CLI surface, features, workspace layoutPARITY.md— parity status for the Rust portrust/MOCK_PARITY_HARNESS.md— deterministic mock-service harness detailsROADMAP.md— active roadmap and open cleanup workPHILOSOPHY.md— why the project exists and how it is operated
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.