Grok 4 Fast Reasoning
JSON →A fast inference variant of Grok 4 optimized for reasoning tasks.
Specs
context window 2.0M tokens
max output 2.0M tokens
input price $0.2 / 1M tokens
output price $0.5 / 1M tokens
Capabilities
streamingreasoningcode-generationfunction-callingtool-useprompt-caching
API
full doc /v1/models/grok-4-fast-reasoning