On August 28, 2025, xAI officially launched Grok Code Fast1, a fast and cost-effective large language model specifically designed for software development. With its outstanding reasoning capabilities and efficient code generation performance, the model marks a significant breakthrough for xAI in the AI coding assistant field. Currently, Grok Code Fast1 is freely available on multiple mainstream intelligent programming platforms, including GitHub Copilot, Cursor, Cline, Kilo Code, Roo Code, opencode, and Windsurf, providing developers with a powerful programming tool option.
New Architecture, Focused on Speed and Cost-Effectiveness
Grok Code Fast1 adopts a brand-new lightweight model architecture developed from scratch by the xAI team, combined with innovative reasoning acceleration technologies and efficient prompt caching optimization techniques. According to xAI, the model has achieved significant improvements in service speed, with cache hit rates typically exceeding 90%, offering developers a very smooth response experience. The pre-training corpus of the model focuses on programming content and has been fine-tuned specifically for real-world coding tasks, enabling it to efficiently handle various tasks such as code snippet generation, debugging, and optimization.
xAI stated that Grok Code Fast1 performs well in full-stack development, especially excelling in programming languages such as TypeScript, Python, Java, Rust, C++, and Go. It can complete project building from scratch with minimal supervision, provide in-depth code library explanations, and even perform precise error fixes, demonstrating its strong potential in the agent coding field.
Widespread Integration, Free Trial
To allow more developers to experience the excellent performance of Grok Code Fast1, xAI has partnered with multiple platforms to offer a one-week free trial at launch. Supported platforms include:
GitHub Copilot**: One of the most well-known AI coding assistants, Grok Code Fast1 is integrated as an optional public preview into GitHub Copilot's Pro, Pro+, Business, and Enterprise plans. Enterprise users need administrators to enable the Grok Code Fast1 policy in Copilot settings, while individual users can enable it through the model selector in Visual Studio Code.
- **Cursor**: An AI-enhanced code editor based on Visual Studio Code, offering a seamless Grok Code Fast1 experience.
- **Cline**: An open-source AI coding assistant, favored by developers for its autonomous agent mode and multi-file editing capabilities.
- **Kilo Code**: A rapidly growing open-source AI coding extension with 240,000 downloads, offering unlimited free access to Grok Code Fast1.
- **Roo Code**: A coding tool that provides AI agent team functionality, emphasizing "as-is" service with disclaimers.
- **opencode**: Offers free access to Grok Code Fast1, allowing developers to quickly experience it through the model selector.
- **Windsurf**: An AI-driven IDE developed by Codeium, known for its real-time code awareness and efficient auto-completion features.
Developers can simply select Grok Code Fast1 on any of the above platforms to enjoy a free trial. xAI also mentioned that they will collect usage data during the trial period to further optimize model performance.
Developer Feedback and Practical Applications
The release of Grok Code Fast1 has sparked a warm response within the developer community. One developer built a combat simulator prototype on the Cursor platform within just one day, praising its quick response and accurate instruction execution, which significantly improved development efficiency. xAI also shared a guide on prompt engineering for optimizing the use of Grok Code Fast1, suggesting that developers use stage-by-stage and task-focused prompts to achieve rapid iteration and precise control for optimal results.
Meanwhile, xAI revealed that Grok Code Fast1 was tested under the codename "Sonic" in a small-scale trial before its release, and the team rapidly iterated multiple model checkpoints based on community feedback to ensure its performance and stability.
Pricing and Future Plans
After the free trial period, Grok Code Fast1 will be available through the xAI API, with pricing at $0.20 per million input tokens, $1.50 per million output tokens, and $0.02 per million cached input tokens. This pricing strategy makes it one of the most cost-effective AI coding models in the market.
xAI stated that Grok Code Fast1 will be updated frequently, with improvement cycles measured in days rather than weeks. The team is already working on new variants that support multimodal input, parallel tool calls, and extended context length, further enhancing the model's flexibility and functionality.
The launch of Grok Code Fast1 allows xAI to directly compete with industry giants like OpenAI and Microsoft in the AI coding assistant field. As a model emphasizing speed and cost-effectiveness, Grok Code Fast1 offers developers a lightweight and efficient choice, particularly suitable for individual developers or small to medium-sized teams with limited budgets.
