Grok Build — xAI Coding Agent Harness with Fullscreen TUI

Introduction

Grok Build is an open-source coding agent harness developed by xAI. It provides a fullscreen, mouse-interactive terminal user interface for building software with Grok language models. The harness is written in Rust and designed for extensibility, letting developers customize agent behavior and tool integrations.

What Grok Build Does

• Provides a fullscreen TUI with mouse interactivity for navigating code changes and agent output
• Runs Grok models as the backend for code generation, editing, and debugging tasks
• Supports file editing, shell command execution, and multi-file project navigation from the terminal
• Offers an extensible plugin architecture for adding custom tools and workflows
• Ships as a single Rust binary with minimal system dependencies

Architecture Overview

Grok Build is built in Rust using a reactive TUI framework. It communicates with xAI's Grok API for language model inference while managing local file operations, shell execution, and diff rendering in-process. The harness maintains a conversation context window and supports tool-use patterns where the model can read files, write code, and run commands. The fullscreen layout divides the terminal into panels for conversation, file tree, and diff views.

Self-Hosting & Configuration

• Install via cargo install grok-build or download prebuilt binaries from the GitHub Releases page
• Set your xAI API key via the GROK_API_KEY environment variable
• Configure default model, context window size, and tool permissions in ~/.config/grok-build/config.toml
• The harness runs entirely in your terminal with no browser or GUI dependencies
• Works on macOS, Linux, and Windows (via WSL or native)

Key Features

• Fullscreen interactive TUI with mouse support for a modern terminal experience
• Written in Rust for fast startup and low memory usage
• Extensible architecture allows adding custom tools and agent behaviors
• Built-in diff viewer highlights proposed code changes before applying them
• Open-source under an open license with active development from xAI

Comparison with Similar Tools

• Claude Code — Anthropic's CLI agent; Grok Build is xAI's counterpart using Grok models
• OpenCode — open-source terminal agent; Grok Build offers a more polished fullscreen TUI
• Codex CLI — OpenAI's terminal agent; Grok Build focuses on Grok models and extensibility
• Aider — multi-model terminal coding tool; Grok Build provides a richer interactive interface
• Cursor — IDE-based agent; Grok Build is terminal-native without an editor dependency

FAQ

Q: Which language models does Grok Build use? A: It connects to xAI's Grok API by default. The extensible architecture may support additional providers through plugins.

Q: Does Grok Build require a paid API key? A: Yes, you need a valid xAI API key to access Grok models. Check xAI's pricing for current rates.

Q: What operating systems are supported? A: Grok Build runs on macOS, Linux, and Windows (native or WSL). Prebuilt binaries are available for major platforms.

Q: Can I use Grok Build without mouse support? A: Yes, the TUI supports full keyboard navigation. Mouse interactivity is an optional enhancement.

Sources

• https://github.com/xai-org/grok-build