SpaceXAI (formerly xAI), led by Elon Musk, open-sourced the source code for its AI coding agent “Grok Build” on July 15 (July 16 Japan time). The company announced on its official X account that it had “open-sourced Grok Build and reset usage limits for all users.” The code is released under the Apache License Version 2.0 and is available in the “xai-org/grok-build” repository on GitHub.

This open-sourcing move appears to be a response to revelations that Grok Build was transmitting users’ codebases and authentication credentials to SpaceXAI’s servers. SpaceXAI explained that it disabled the data upload feature by default on July 12 and deleted all previously uploaded coding data. In a subsequent post on July 15, the company acknowledged that the data upload feature was enabled by default in the initial beta version, while asserting that “Grok Build has fully respected Zero Data Retention (ZDR),” and that when users disabled data uploads via the CLI, that choice was always honored.

Grok Build is an AI agent released in May 2026, equipped with automated coding capabilities powered by Grok 4.5. Beyond autonomous code execution, it supports querying Grok within the terminal, planning coding tasks via Plan mode, and extending functionality through Skills and MCP servers. With the open-source release, users can now compile Grok Build in their own environments and run it in a fully local-first manner when paired with local inference infrastructure.

SpaceXAI emphasized the significance of open-sourcing, stating that “by reading the source code, you can understand the complete operational principles, from context building to tool call distribution.” The company further stressed that for developers using Agent Skills, plugins, hooks, MCP servers, and sub-agents, the code serves as a “trusted reference” for understanding how each component is loaded and invoked.

The company is also encouraging users who discover vulnerabilities in Grok Build to report them through HackerOne.

Musk Also Announces Plan to Fully Open-Source X’s Codebase

In parallel with the Grok Build open-sourcing, Musk revealed plans on July 15 to open-source the entire codebase of X (formerly Twitter). “Once the security vulnerability review is complete, the entire X codebase will be open-sourced without exception,” he posted. Details such as the release date, repository, software license, and technical definition of scope have not been disclosed.

X has already published the core recommendation system powering its “For You” feed, but Musk’s stated plan goes far beyond that, targeting the entire platform. He also indicated an intention to bring in independent third-party reviewers to verify that systems running in production match the published source code. This addresses a fundamental limitation of open-sourcing: the inability to externally confirm that the public code is identical to what is actually running.

X’s product scope has expanded beyond its original social feed, and software with significant privacy and security implications—such as “XChat,” which features encrypted messaging, calling, and Grok integration—could also fall within the scope of the disclosure. Across Musk’s broader technology group, SpaceX’s acquisition of Anysphere (the parent company of Cursor) is also driving integration between Cursor’s coding tools and the Grok Build and xAI development stack.

Impact and Outlook of the Open-Sourcing

The open-sourcing of Grok Build could reshape the competitive landscape of the AI coding assistant market. Against existing tools like GitHub Copilot and Cursor, a fully local, source-available alternative may attract developers who prioritize security and privacy.

Meanwhile, while the plan to fully open-source X’s codebase could significantly advance platform transparency, it also carries risks of exposing credentials, private data, internal security controls, and infrastructure details. The duration of the security review remains unspecified, and how ongoing updates will be provided post-publication has not been clarified.