claw-code/rust/README.md

🦞 Claw Code — Rust Implementation

A high-performance Rust rewrite of the Claw Code CLI agent harness. Built for speed, safety, and native tool execution.

Quick Start

# Build
cd rust/
cargo build --release

# Run interactive REPL
./target/release/claw

# One-shot prompt
./target/release/claw prompt "explain this codebase"

# With specific model
./target/release/claw --model sonnet prompt "fix the bug in main.rs"

Configuration

Set your API credentials:

export ANTHROPIC_API_KEY="sk-ant-..."
# Or use a proxy
export ANTHROPIC_BASE_URL="https://your-proxy.com"

Or authenticate via OAuth:

claw login

Mock parity harness

The workspace now includes a deterministic Anthropic-compatible mock service and a clean-environment CLI harness for end-to-end parity checks.

cd rust/

# Run the scripted clean-environment harness
./scripts/run_mock_parity_harness.sh

# Or start the mock service manually for ad hoc CLI runs
cargo run -p mock-anthropic-service -- --bind 127.0.0.1:0

Harness coverage:

• streaming_text
• read_file_roundtrip
• grep_chunk_assembly
• write_file_allowed
• write_file_denied

Primary artifacts:

• crates/mock-anthropic-service/ — reusable mock Anthropic-compatible service
• crates/rusty-claude-cli/tests/mock_parity_harness.rs — clean-env CLI harness
• scripts/run_mock_parity_harness.sh — reproducible wrapper

Features

Feature	Status
Anthropic API + streaming	✅
OAuth login/logout	✅
Interactive REPL (rustyline)	✅
Tool system (bash, read, write, edit, grep, glob)	✅
Web tools (search, fetch)	✅
Sub-agent orchestration	✅
Todo tracking	✅
Notebook editing	✅
CLAUDE.md / project memory	✅
Config file hierarchy (.claude.json)	✅
Permission system	✅
MCP server lifecycle	✅
Session persistence + resume	✅
Extended thinking (thinking blocks)	✅
Cost tracking + usage display	✅
Git integration	✅
Markdown terminal rendering (ANSI)	✅
Model aliases (opus/sonnet/haiku)	✅
Slash commands (/status, /compact, /clear, etc.)	✅
Hooks (PreToolUse/PostToolUse)	🔧 Config only
Plugin system	📋 Planned
Skills registry	📋 Planned

Model Aliases

Short names resolve to the latest model versions:

Alias	Resolves To
opus	claude-opus-4-6
sonnet	claude-sonnet-4-6
haiku	claude-haiku-4-5-20251213

CLI Flags

claw [OPTIONS] [COMMAND]

Options:
  --model MODEL                    Set the model (alias or full name)
  --dangerously-skip-permissions   Skip all permission checks
  --permission-mode MODE           Set read-only, workspace-write, or danger-full-access
  --allowedTools TOOLS             Restrict enabled tools
  --output-format FORMAT           Output format (text or json)
  --version, -V                    Print version info

Commands:
  prompt <text>      One-shot prompt (non-interactive)
  login              Authenticate via OAuth
  logout             Clear stored credentials
  init               Initialize project config
  doctor             Check environment health
  self-update        Update to latest version

Slash Commands (REPL)

Tab completion now expands not just slash command names, but also common workflow arguments like model aliases, permission modes, and recent session IDs.

Command	Description
/help	Show help
/status	Show session status (model, tokens, cost)
/cost	Show cost breakdown
/compact	Compact conversation history
/clear	Clear conversation
/model [name]	Show or switch model
/permissions	Show or switch permission mode
/config [section]	Show config (env, hooks, model)
/memory	Show CLAUDE.md contents
/diff	Show git diff
/export [path]	Export conversation
/session [id]	Resume a previous session
/version	Show version

Workspace Layout

rust/
├── Cargo.toml              # Workspace root
├── Cargo.lock
└── crates/
    ├── api/                # Anthropic API client + SSE streaming
    ├── commands/           # Shared slash-command registry
    ├── compat-harness/     # TS manifest extraction harness
    ├── mock-anthropic-service/ # Deterministic local Anthropic-compatible mock
    ├── runtime/            # Session, config, permissions, MCP, prompts
    ├── rusty-claude-cli/   # Main CLI binary (`claw`)
    └── tools/              # Built-in tool implementations

Crate Responsibilities

• api — HTTP client, SSE stream parser, request/response types, auth (API key + OAuth bearer)
• commands — Slash command definitions and help text generation
• compat-harness — Extracts tool/prompt manifests from upstream TS source
• mock-anthropic-service — Deterministic /v1/messages mock for CLI parity tests and local harness runs
• runtime — ConversationRuntime agentic loop, ConfigLoader hierarchy, Session persistence, permission policy, MCP client, system prompt assembly, usage tracking
• rusty-claude-cli — REPL, one-shot prompt, streaming display, tool call rendering, CLI argument parsing
• tools — Tool specs + execution: Bash, ReadFile, WriteFile, EditFile, GlobSearch, GrepSearch, WebSearch, WebFetch, Agent, TodoWrite, NotebookEdit, Skill, ToolSearch, REPL runtimes

Stats

• ~20K lines of Rust
• 7 crates in workspace
• Binary name: claw
• Default model: claude-opus-4-6
• Default permissions: danger-full-access

License

See repository root.