Grok 4.1 Fast
xAI
xai/grok-4.1-fast
Reasoning model, 256K context
Context Window
256K
256,000 tokens
Max Output
33K
32,768 tokens
About this model
Grok 4.1 Fast β latest reasoning model
This model supports up to 256K tokens of context. It excels at complex reasoning, mathematical problems, and multi-step tasks. It provides strong code generation and debugging capabilities.
Access it through Chuizi.AI with a single ck- API key β no separate xAI account needed.
Highlights
256K context window
33K max output
Advanced reasoning
Strong code generation
Best For
Complex coding tasksAlgorithm designCode reviewTechnical architecture
2025-11-01
Capabilities
ChatVisionReasoningCodecachetools
Aliases
grok-4.1-fastPricing (per 1M tokens)
| Pricing (per 1M tokens) | / 1M tokens |
|---|---|
| Input / 1M | $0.21 |
| Output / 1M | $0.53 |
| Cache Read | $0.02 |
Final prices shown
Quick Start
main.py
from openai import OpenAI client = OpenAI( base_url="https://api.chuizi.ai/v1", api_key="ck-your-key-here", ) response = client.chat.completions.create( model="xai/grok-4.1-fast", messages=[{"role": "user", "content": "Hello!"}], ) print(response.choices[0].message.content)