Claw Code

Claw Code is an open-source AI coding agent framework written in Python and Rust. It is a clean-room rewrite of the Claude Code agent harness architecture, created by Sigrid Jin after the March 2026 source code leak event. The codebase is composed of Rust (72.9%) for performance-critical runtime paths and Python (27.1%) for agent orchestration and LLM integration, with an active Rust migration targeting a fully native harness.

The framework ships with 19 permission-gated tools, 15 slash commands, and a multi-agent orchestration layer that can spawn sub-agents to parallelize complex tasks. It features a provider-agnostic API client supporting Claude, OpenAI, and local models, full Model Context Protocol (MCP) integration across 6 transport types, multi-layer session and memory persistence, and a three-mode permission system. Performance-critical paths are handled by a 6-crate Rust workspace with a zero-dependency JSON parser, OAuth PKCE flow, and syntax-highlighted terminal rendering.

Claw Code has accumulated over 48,000 stars and 56,000 forks on GitHub under the instructkr organization. It is freely available, auditable, and welcomes community contributions.