Core Insights - xAI has launched two major updates for its xAI API: Grok 4.1 Fast and Agent Tools API, focusing on fast, low-cost, and agent-centric models [2][3] Group 1: Grok 4.1 Fast Model - Grok 4.1 Fast is the best-performing tool invocation model to date, supporting a context window of 2 million tokens, excelling in customer support and financial applications [2][3] - The model has risen to sixth place in the Artificial Intelligence Index (AII), scoring 93.3% on the τ²-Bench Telecom leaderboard, outperforming GPT-5.1 (high) and Gemini 3 Pro by a significant margin [3][9] - Grok 4.1 Fast has improved factual accuracy, with a hallucination rate reduced by 50% compared to Grok 4 Fast [3][32] Group 2: Agent Tools API - The Agent Tools API allows agents to access real-time X data, web searches, and remote code execution, significantly enhancing the capabilities of Grok 4.1 Fast [6][31] - Developers can easily implement the Agent Tools API to enable Grok to browse the web, search X posts, execute code, and retrieve uploaded documents with minimal coding [27][31] Group 3: Performance and Pricing - Grok 4.1 Fast's pricing is set at $0.20 per million input tokens, $0.50 per million output tokens, and $5 for 1,000 successful API calls, with a free trial available until December 3 [8][9] - The model has shown superior performance in real-time information retrieval compared to Grok 4 Fast, although it has faced challenges in classic programming tasks [14][21] Group 4: Market Context and Future Outlook - The launch of Grok 4.1 Fast and the Agent Tools API reflects a shift in the AI industry towards agent-focused models, driven by market demand for enhanced capabilities [35] - xAI's emphasis on practical application integration positions it favorably in the competitive landscape of AI model development, although the stability of Grok 4.1 Fast's performance remains to be validated through further testing [35]

Grok 4.1 Fast just released with our new Agent Tools API that has direct access to 𝕏 data, web browsing and code executionhttps://t.co/zKUYtHQbtq ...

RT Eric Jiang (@veggie_eric)🚀We just dropped the best tool calling model on the planet.Powered by our new Agent Tools API with direct access to X data, web browsing, code execution, and more. ...