rust

🦞 Claw Code — Rust Implementation

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

For a task-oriented guide with copy/paste examples, see ../USAGE.md.

Quick Start

# Inspect available commands
cd rust/
cargo run -p rusty-claude-cli -- --help

# Build the workspace
cargo build --workspace

# Run the interactive REPL
cargo run -p rusty-claude-cli -- --model claude-opus-4-6

# One-shot prompt
cargo run -p rusty-claude-cli -- prompt "explain this codebase"

# JSON output for automation
cargo run -p rusty-claude-cli -- --output-format json prompt "summarize src/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 and let the CLI persist credentials locally:

cargo run -p rusty-claude-cli -- 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
• multi_tool_turn_roundtrip
• bash_stdout_roundtrip
• bash_permission_prompt_approved
• bash_permission_prompt_denied
• plugin_tool_roundtrip

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
• scripts/run_mock_parity_diff.py — scenario checklist + PARITY mapping runner
• mock_parity_scenarios.json — scenario-to-PARITY manifest

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                    Override the active model
  --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           Non-interactive output format (text or json)
  --resume SESSION                 Re-open a saved session or inspect it with slash commands
  --version, -V                    Print version and build information locally

Commands:
  prompt <text>      One-shot prompt (non-interactive)
  login              Authenticate via OAuth
  logout             Clear stored credentials
  init               Initialize project config
  status             Show the current workspace status snapshot
  sandbox            Show the current sandbox isolation snapshot
  agents             Inspect agent definitions
  mcp                Inspect configured MCP servers
  skills             Inspect installed skills
  system-prompt      Render the assembled system prompt

For the current canonical help text, run cargo run -p rusty-claude-cli -- --help.

Slash Commands (REPL)

Tab completion expands slash commands, 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
/resume [id]	Resume a saved conversation
/session [id]	Resume a previous session
/version	Show version

See ../USAGE.md for examples covering interactive use, JSON automation, sessions, permissions, and the mock parity harness.

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
    ├── plugins/            # Plugin registry and hook wiring primitives
    ├── runtime/            # Session, config, permissions, MCP, prompts
    ├── rusty-claude-cli/   # Main CLI binary (`claw`)
    ├── telemetry/          # Session tracing and usage telemetry types
    └── 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
• plugins — Plugin metadata, registries, and hook integration surfaces
• 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
• telemetry — Session trace events and supporting telemetry payloads
• tools — Tool specs + execution: Bash, ReadFile, WriteFile, EditFile, GlobSearch, GrepSearch, WebSearch, WebFetch, Agent, TodoWrite, NotebookEdit, Skill, ToolSearch, REPL runtimes

Stats

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

License

See repository root.