grok-4-1-fast-reasoning — API, Pricing & Context Window | Vivgrid

grok-4-1-fast-reasoning — API, Pricing & Context Window

grok-4-1-fast-reasoning is xAI's fast reasoning model, pairing an enormous 2M-token context window with image input and an emphasis on quick, structured problem solving. The large context makes it well suited to sprawling documents and long agent histories.

On Vivgrid, grok-4-1-fast-reasoning is available through the unified, OpenAI-compatible API, so xAI slots into multi-provider agent stacks with a single key.

Specifications
Provider xAI
Model ID grok-4-1-fast-reasoning
Best for General-purpose
Context window 2,000,000 tokens
Modalities Text, Image
Tool / function calling Yes
Knowledge cutoff 2025-06
Acceleration 🌐 Global (Centralized)

Pricing

Pricing for grok-4-1-fast-reasoning matches the provider's published rates. See live pricing in the Vivgrid Console.

Quick start

Call grok-4-1-fast-reasoning through Vivgrid's unified, OpenAI-compatible endpoint. Get an API key from the Vivgrid Console.

curl https://api.vivgrid.com/v1/chat/completions \
  -H "Authorization: Bearer $VIVGRID_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "grok-4-1-fast-reasoning",
    "messages": [\
      { "role": "user", "content": "Say hello in English, Chinese and Spanish." }\
    ],
    "stream": true
  }'

Ideal use cases

Related models