Grok Build is open source

TL;DR Highlight

SpaceXAI open-sourced its Rust terminal coding agent CLI/TUI under Apache-2.0.

Who Should Read

Developers who want to dig into the harness internals of coding agents like Claude Code or Codex

Core Mechanics

A terminal AI coding agent
- Grok Build is SpaceXAI's terminal-based coding agent.
- It runs as a full-screen TUI that understands your codebase, edits files, and runs shell commands.
- It also searches the web and manages long-running tasks.
Three ways to run it
- Use it interactively in the TUI.
- Run it headlessly for scripts and CI.
- Embed it in editors via ACP (Agent Client Protocol).
Rust workspace layout
- Crates split the TUI, agent runtime, tool implementations, and workspace (filesystem, VCS, checkpoints).
- The binary is named xai-grok-pager, and official installs ship it as grok.
License and contribution policy
- First-party code is Apache-2.0.
- External contributions are not accepted.
- It syncs periodically from SpaceXAI's monorepo, and SOURCE_REV records the commit SHA.

Community Reactions

Surprising features in the code
- One commenter noted a terminal Mermaid renderer using Unicode box-drawing.
- Another said the amount of code seems huge for what it offers and doesn't look intentionally designed.
Forks appeared right away
- A commenter listed a privacy fork with telemetry stripped (gork-build).
- Others include a multi-provider CLI, a Tauri desktop GUI, and a theming fork.
Concerns about user data upload
- Commenters mentioned an upset days earlier over forfeiting the whole working directory.
- One said claims of data deletion aren't trustworthy without third-party certification.
Advice to run it in a sandbox
- A commenter suggested Docker Sandboxes and `sbx policy log` to see allowed and blocked requests.
- They noted it doesn't replace reading the code.
Mixed reviews of quality

How to Apply

Build from source and skim the agent structure
- Run `cargo run -p xai-grok-pager-bin` today after installing dotslash.
- Read the tool implementations in `crates/codegen/xai-grok-tools`.
Compare with your own agent's tool design
- If you build agents, compare xai-grok-workspace's checkpoint and execution split with your design.
- List the terminal, file-edit, and search tool implementations as references.
Run it inside a sandbox
- Don't run the install script directly; try it in an isolated environment first.
- Set an explicit network allowlist and check the request logs.

Try It

copy & run

# Paste into a terminal (macOS/Linux) - build and run Grok Build from source

cargo install dotslash

git clone https://github.com/xai-org/grok-build
cd grok-build

cargo run -p xai-grok-pager-bin

# Next: open the tools folder to see the agent's tool list
# ls crates/codegen/xai-grok-tools

Terminology

HarnessThe wrapper program that coordinates tool calls, file edits, and command execution around an LLM. Think of it as the chassis around the engine (the model).

TUIA full-screen UI that runs inside the terminal. It's an app interface built for the terminal instead of the web.

ACP (Agent Client Protocol)A protocol for editors to talk to coding agents. Like a standard USB port between editor and agent.

DotSlashA tool that automatically downloads and runs build-time tools such as protoc.