xAI has unveiled Grok Code Fast 1, a new reasoning model designed specifically for agentic coding workflows, positioning it as both faster and more cost-efficient than competing systems. The model is immediately available through the xAI API and, for a limited time, can be accessed for free via developer platforms including GitHub Copilot, Cursor, Cline, Roo Code, KiloCode, opencode, and Windsurf.
Built from the ground up with a new architecture and training datasets rich in programming material, Grok Code Fast 1 is engineered to support real-world software development tasks. According to xAI, the system has been fine-tuned on workflows such as pull requests and bug fixes, making it highly relevant for day-to-day coding needs.
“Empowering developers with powerful tools is a core part of our mission at GitHub Copilot, and this is a compelling new option for our developers,” said GitHub CPO Mario Rodriguez. Early users have already praised the model’s performance. Developer Danny Limanseta noted its responsiveness, saying he “had to change up how I work in Cursor.”
In terms of raw performance, Grok Code Fast 1 processes 190 tokens per second, outpacing leading models such as GPT-5, Gemini 2.5 Pro, and Claude Sonnet 4. Pricing has also been set competitively at $0.20 per million input tokens and $1.50 per million output tokens. On the SWE-bench Verified benchmark, the model achieved a 70.8% accuracy score. However, xAI emphasized that human feedback from real-world coding workflows has been instrumental in refining the system’s capabilities.
The model is language-agnostic, with support for popular programming languages such as TypeScript, Python, Java, Rust, C++, and Go. Its applications span a broad range of developer needs, including new project creation, bug resolution, and iterative code improvements.
Internally known as “Sonic” during its stealth development phase, Grok Code Fast 1 will continue to receive frequent updates. xAI also confirmed that a multimodal version of the model is already in training, promising enhanced features such as parallel tool calling and extended context windows.
With Grok Code Fast 1, xAI aims to strengthen its position in the rapidly evolving AI-assisted software development landscape, giving developers a faster, more flexible, and cost-effective coding companion.
