Grok 4.1 Fast Reasoning API

Model details

Context window

128K tokens

Max output

128K tokens

Input

Text, images

Output

Text

Capabilities

Reasoning, Vision, Tool calling, Streaming, JSON output

Interfaces

OpenAI-style Chat Completions, Anthropic-style Messages, OpenAI-style Responses

Why teams pick it

• Grok 4.1 Fast Reasoning for OpenAI-style Chat Completions, Anthropic-style Messages, OpenAI-style Responses.

Call Grok 4.1 Fast Reasoning

Grok 4.1 Fast Reasoning answers on any of the APIs below — pick the one your code already speaks and just swap in your Inferray key.

curl https://api.inferray.com/v1/chat/completions \
  -H "Authorization: Bearer inferray_..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "grok-4-1-fast-reasoning",
  "messages": [
    {
      "role": "user",
      "content": "Hello"
    }
  ]
}'

curl https://api.inferray.com/v1/messages \
  -H "Authorization: Bearer inferray_..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "grok-4-1-fast-reasoning",
  "max_tokens": 1024,
  "messages": [
    {
      "role": "user",
      "content": "Hello"
    }
  ]
}'

curl https://api.inferray.com/v1/responses \
  -H "Authorization: Bearer inferray_..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "grok-4-1-fast-reasoning",
  "input": "Hello"
}'

Use Grok 4.1 Fast Reasoning in your tools

Every coding agent below has a setup guide. Set the model to grok-4-1-fast-reasoning.

• Claude Code
• Codex
• opencode
• Cline
• Roo Code
• Aider
• Continue

More from xAI

Alternatives to Grok 4.1 Fast Reasoning

• DeepSeek V4.1 FlashReasoning and vision at a fraction of flagship prices.DeepSeek
• GPT-4o MiniGPT-4o Mini for OpenAI-style Chat Completions, Anthropic-style Messages, OpenAI-style Responses.OpenAI
• MiniMax M3.1 FlashMiniMax M3.1 Flash for OpenAI-style Chat Completions, Anthropic-style Messages, OpenAI-style Responses.MiniMax

Questions about this model

How much does the Grok 4.1 Fast Reasoning API cost?

Grok 4.1 Fast Reasoning costs $0.2 per 1M input tokens and $0.5 per 1M output tokens on Inferray, and cached input is $0.05 per 1M. That is the list price, with no gateway fee on top.

Is there a free tier for Grok 4.1 Fast Reasoning?

No. You add credit and pay Grok 4.1 Fast Reasoning's list rate for each request — seats, projects, and API keys are free, and pay-as-you-go credit never expires.

Am I charged for failed requests?

No. A request that fails without returning a result is not billed. If a response fails part-way, the tokens already processed before the failure are charged.

Is Grok 4.1 Fast Reasoning included in Token Plans?

No. Grok 4.1 Fast Reasoning is pay-as-you-go only; Token Plans cover the other text models in the catalog.

Can I use Grok 4.1 Fast Reasoning in Claude Code?

Yes. Set ANTHROPIC_BASE_URL to https://api.inferray.com, ANTHROPIC_AUTH_TOKEN to your Inferray key, and ANTHROPIC_MODEL to grok-4-1-fast-reasoning. The same key works in Codex, opencode, Cline, and other agents.

Does Grok 4.1 Fast Reasoning support tool calling and vision?

Grok 4.1 Fast Reasoning supports tool calling, image input, reasoning, JSON output and streaming on Inferray.

Is it the real Grok 4.1 Fast Reasoning?

Yes. A request for grok-4-1-fast-reasoning is answered by Grok 4.1 Fast Reasoning from xAI, billed at its published list price. Inferray never substitutes a different or smaller model.