Name: Grok Code Fast 1 API
Brand: xAI

Overview

Grok Code Fast 1 Description

Grok Code Fast 1 is xAI's specialized, fast, and economical coding assistant optimized for agentic coding workflows. It excels at handling high-volume, practical software development tasks including code generation, debugging, editing, and multi-step agentic operations. Built with speed, efficiency, and cost-effectiveness in mind, Grok Code Fast 1 is particularly proficient in TypeScript, Python, Java, Rust, C++, and Go, offering deep integration into developer pipelines with structured, traceable reasoning outputs.

Technical Specification

Performance Benchmarks

Context Window: 256,000 tokens (max prompt + response)
Max Output: Up to 16,000 tokens (playground capped)
Architecture: 314B-parameter Mixture-of-Experts (MoE) for speed and capability
Throughput: ~92 tokens per second

Performance Metrics

Accurate across coding tasks with 93.0% coding accuracy and 75.0% instruction following accuracy
Strong classification and knowledge performances: perfect in morality, email classification, general knowledge
Reasoning Accuracy: 80.0%, with visible step-by-step reasoning traces for developer inspection and steering
Competitive speed and throughput supporting real-time coding workflows

__wf_reserved_inherit — Token usage data on OpenRouter places Grok Code Fast 1 at the forefront of active models, underpinning its competitive speed and efficiency in delivering real-time coding assistance.

API Pricing

$0.26 per million input tokens
$1.95 per million output tokens

Key Capabilities

Massive long-context handling for entire codebases or multi-file projects
Agentic coding with native function/tool calls and multi-step operation chaining
Traceable reasoning outputs revealing intermediate steps to boost transparency and steerability
Multi-language support for practical software stacks including major modern programming languages
Economical pricing designed for high-volume developer use and iterative workflows

Optimal Use Cases

Agentic coding assistants for autonomous code writing, debugging, and system integration
Large-scale codebase analysis and multi-file editing without coherence loss
Coding research and evaluation demanding precise reasoning and logic transparency
Integration into CI/CD pipelines with high throughput and cost efficiency

Code Sample

Comparison with Other Models

vs. Grok 4: Grok Code Fast 1 trades some general reasoning and tool-use sophistication for much higher speed and cost efficiency specifically in coding workflows. Grok 4 better supports complex AGI-style reasoning and tool integration beyond coding.

vs. Claude 4 Opus: Claude excels in language safety and nuanced instruction following, while Grok Code Fast 1 delivers faster, structured agentic coding with visible reasoning traces.

vs. GPT-4o: GPT-4o leads in multimodal and browsing features; Grok Code Fast 1 focuses on coding speed, throughput, and agentic tool-enabled workflows.

Limitations

Text-only input/output; no vision, audio, or multimodal modalities
No built-in reasoning beyond coding tasks; focused on practical tool-assisted code generation
Only available on-demand in selected US regions, no dedicated server mode yet
No support for streaming outputs or offline/local inference

Uptime and performance

Uptime (24h): 100%
Uptime (7d): 100%
Availability (24h): 88.0%
Error rate (24h): 13.0%

Measured on the AI/ML API gateway across live traffic. Figures are medians unless stated. Last updated 2026-10-12.

Use cases

Agentic coding assistants for autonomous code writing, debugging, and system integration
Large-scale codebase analysis and multi-file editing without coherence loss
Coding research and evaluation demanding precise reasoning and logic transparency
Integration into CI/CD pipelines with high throughput and cost efficiency

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How to use Grok Code Fast 1 API

Install any OpenAI-compatible SDK, point it at api.aimlapi.com/v1, and set the model to x-ai/grok-code-fast-1.

import requests

r = requests.post(
    "https://api.aimlapi.com/v1/chat/completions",
    headers={"Authorization": "Bearer " + AIMLAPI_KEY},
    json={
      "model": "x-ai/grok-code-fast-1",
      "messages": [
        {
          "role": "user",
          "content": "Hello!"
        }
      ]
    },
)
print(r.json())

const r = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "x-ai/grok-code-fast-1",
    "messages": [
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }),
});
console.log(await r.json());

curl -X POST https://api.aimlapi.com/v1/chat/completions \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"x-ai/grok-code-fast-1","messages":[{"role":"user","content":"Hello!"}]}'

OpenAI-compatible — swap the base URL and it works with your existing SDK.