Grok Code Fast 1

December 17, 2025

TL;DR

Grok-code-fast-1 is a new AI model optimized for agentic coding, designed to be fast and economical.
It features a new architecture and training corpus rich in programming content, with post-training on real-world coding tasks.
The model is proficient with tools like grep, terminal, and file editing, and integrates with IDEs.
It is available for free for a limited time through launch partners including GitHub Copilot, Cursor, and others.
Innovative techniques accelerate serving speed, providing a responsive user experience with high prompt caching rates.
Grok-code-fast-1 supports TypeScript, Python, Java, Rust, C++, and Go, and can perform tasks from project building to bug fixing.
Its pricing is set at $0.20 per million input tokens, $1.50 per million output tokens, and $0.02 per million cached input tokens.
Performance is evaluated using benchmarks like SWE-Bench-Verified and real-world human assessments, with grok-code-fast-1 scoring 70.8% on SWE-Bench.
The model was recently released in stealth under the codename 'sonic', with ongoing updates and improvements planned, including a multimodal variant.

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