grok-4-fast-reasoning

AvailablexaiChat

Pricing

Official price	Catalog price	Discount
Input $0.20 / Output $0.50	Input $0.20 / Output $0.50	-

Capabilities

JSON ModePrompt CacheReasoningTool UseVision

Context: 2M
Max output: 16K

Supported operations

Aliases

grok-4-fast-reasoning-latest

API Base

Example request

https://api.aisonar.dev

curl https://api.aisonar.dev/v1/chat/completions \
  -H "Authorization: Bearer $AI_SONAR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "grok-4-fast-reasoning",
    "messages": [{"role":"user","content":"Summarize this release note"}]
  }'