Grok Build Is Now Open Source

xAI announced the open-sourcing of Grok Build on July 15, 2026, including the complete source code for the coding agent and terminal UI. The open-source code covers the agent loop, tool system, terminal UI, and extension system (skills, plugins, hooks, MCP servers, subagents), and supports local-first operation: users can compile it themselves, point to a local inference engine, and configure via config.toml.

xAI stated that open-sourcing is the most direct way to build a robust and reliable harness, and the source code serves as an authoritative reference for extensions. The code is hosted on GitHub, and users can install and run it with a single command.

Before the open-source release, Grok Build faced criticism after it was revealed that it uploaded all files in user directories to xAI's Google Cloud servers. Users reported that SSH keys, password databases, documents, and photos were transmitted.

In response, Musk announced the deletion of all uploaded user data, xAI disabled the upload feature, and subsequently open-sourced the complete code to rebuild trust. xAI also stated that data storage is disabled by default since July 12, and all user quotas have been reset.

The open-source codebase is approximately 844,530 lines of Rust, covering the agent loop, tools, terminal UI, and extension system. Although the upload feature is disabled, residual traces remain in the code, raising questions about the degree of transparency.

THE DECODER reported that the code is licensed under Apache 2.0, but the official xAI announcement did not specify the license type. The process for community contributions or governance model has not been announced, and long-term support plans are unclear.

After the open-source release, GitHub stars exceeded 10,000 within 20 hours, showing strong community interest. xAI engineers responded to privacy concerns on X, emphasizing the zero data retention (ZDR) policy and inviting users to report issues through a bug bounty program.

However, the actual adoption rate and contribution activity of the community remain unknown, and no comparison of Grok Build's competitiveness with existing coding agents has been provided. Whether this open-sourcing can truly rebuild trust remains to be seen.