xAI open-sources Grok Build, its Rust-based terminal coding agent

xAI has published the Rust source for Grok Build, a full-screen terminal UI coding agent that reads a codebase, edits files, runs shell commands, searches the web, and handles long-running tasks. It works interactively, in headless mode for CI and scripting, or embedded in editors through the Agent Client Protocol. Prebuilt binaries ship for macOS, Linux, and Windows, and the tool authenticates by opening a browser on first launch. First-party code carries an Apache 2.0 license.

The release is best described as source-available rather than a community project: the repo is synced periodically from an internal monorepo, and the CONTRIBUTING file states external contributions are not accepted. Notably, the third-party notices disclose that Grok Build vendors tool implementations ported from OpenAI’s Codex and the sst/opencode agent, meaning xAI’s entry leans on code from a direct competitor and an existing open-source rival.

The move fits the broader arms race among AI vendors shipping terminal coding agents, where Anthropic’s Claude Code, OpenAI’s Codex CLI, and others compete for developer mindshare. Publishing the source lets users audit and self-build the agent (the binary is internally named xai-grok-pager, installed as grok), even without an open contribution model, and signals xAI’s push to plant Grok directly in developer workflows.