Claw Code is an open-source AI coding agent framework, a new Python and Rust rewrite of the Claude Code architecture. The project originated from the source code leak of Claude Code on March 31, 2026, when developer Sigrid Jin began rewriting it without copyright. The project has a highly modular structure, with 72.9% of the code written in Rust for high-performance execution, and 27.1% in Python for agent orchestration and integration with large language models. Its main advantages include multi-agent orchestration for parallel processing of complex tasks, flexible and fine-grained permission-controlled tool invocation, support for multiple transmission protocols through MCP integration, a high-performance query engine, and a multi-session memory system. In terms of pricing, the project is open-source and free, positioning itself as a powerful, flexible, and open-source AI coding assistance solution for developers.