xAI open-sources Grok Build, its terminal coding agent — 840K+ lines of Rust under Apache 2.0

xAI published the full source of Grok Build, its terminal coding agent: roughly 844,000 lines of Rust under Apache 2.0, including its system prompts and tool layer. The release followed a privacy incident in which the tool uploaded excessive repository data to cloud storage; open-sourcing it, alongside a local-inference option, was part of xAI's response.

What it means A complete production agent harness — prompts included — is now readable end to end; it's both a design reference and a cautionary tale about what agent tools quietly send home.