xAI Unveils Grok 4.1 Fast and Agent Tools API for Enhanced Automation
Joerg Hiller Nov 21, 2025 08:24
xAI introduces Grok 4.1 Fast and Agent Tools API, boosting real-world applications in customer support and finance with advanced capabilities.
xAI has launched two significant advancements aimed at enhancing tool-calling capabilities and intelligent automation: Grok 4.1 Fast and the Agent Tools API. These innovations are set to transform the way developers create autonomous agents, particularly in sectors such as customer support and finance.
Grok 4.1 Fast: A New Benchmark in Tool-Calling
Grok 4.1 Fast is xAI's latest tool-calling model featuring a 2-million-token context window. It excels in performing agentic tasks with precision and speed, making it ideal for complex real-world scenarios. This model has been rigorously trained using reinforcement learning across diverse domains, resulting in exceptional performance on the τ²-bench Telecom benchmark, which tests tool use in customer support.
The model's ability to maintain performance over long context lengths and multi-turn interactions marks a significant improvement over previous iterations. It effectively combines high-level reasoning with cost-efficiency, offering a robust solution for developers aiming to build autonomous agents that operate independently.
Agent Tools API: Expanding Capabilities
The newly introduced Agent Tools API provides agents with access to real-time data, web search, remote code execution, and more. This suite of server-side tools allows Grok 4.1 Fast to function as a fully autonomous agent, capable of browsing the web, executing code, and retrieving documents seamlessly.
Key features of the Agent Tools API include search tools for real-time insights, file retrieval with citations, and secure Python code execution. These tools are designed to run entirely on xAI’s infrastructure, eliminating the need for developers to manage API keys or rate limits.
Performance and Accessibility
Grok 4.1 Fast and the Agent Tools API have set new standards in factuality and tool-calling performance. The model has demonstrated superior results on various benchmarks, significantly reducing hallucination rates while matching the performance of earlier models.
For a limited time, xAI is offering free access to Grok 4.1 Fast models and agentic tools via the xAI Agent Tools API on select platforms, including a partnership with OpenRouter. This initiative aims to encourage developers to explore and innovate using these advanced tools.
As the capabilities of autonomous agents continue to grow, xAI's latest offerings provide a powerful foundation for developers to build sophisticated AI solutions tailored to their unique needs.
For more information, visit the xAI website.
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