Grok Build 0.1

• 🔧 Coding model purpose-built for agentic software engineering workflows.
• 📏 256,000-token context window for long-horizon coding.
• 🆕 Launched May 2026 in public beta via xAI API.
• 🔧 Supports tool calls, MCP, web development, and debugging.
• ⚡ Powers xAI's terminal-based Grok Build CLI agent.
• 🌐 Runs in Cursor, Kilo Code, OpenCode, and Hermes Agent.

xAI

xAI is an American artificial intelligence company and wholly owned subsidiary of SpaceX. The company develops AI systems under the Grok brand, spanning language models, image generation, and video synthesis. xAI has quickly established itself as a multimodal…

Grok Build 0.1 is xAI's first model in a dedicated coding family, trained specifically for agentic software engineering rather than general conversation. Released in May 2026 and offered in public beta through the xAI API, it targets multi-step development: autonomously planning, writing, refactoring, and iterating on code, invoking tools, and supporting the Model Context Protocol for web development and debugging. It produces text output across these long-horizon coding loops.

Because this is the family's debut, there is no same-family predecessor to compare against. Functionally, it diverges from xAI's general-purpose flagships such as Grok 4.3, which carries a larger one-million-token context and always-on reasoning, and Grok 4.20 with its two-million-token window and toggleable reasoning. Grok Build 0.1 trades that breadth for a tighter 256,000-token window optimized to hold a mid-sized codebase in memory during long-horizon coding loops.

The model powers xAI's terminal-based Grok Build CLI and runs inside agentic harnesses including Cursor, Kilo Code, OpenCode, and Hermes Agent. It sits alongside multi-agent siblings like Grok 4.20 Multi-Agent in xAI's broader lineup.