Mistral Small 4

POST /v1/chat/completionsHybrid model unifying Instruct, Reasoning (Magistral), and Devstral families: 40% lower completion time and 3x throughput vs Small 3.
At a glance
Pricing
Example request
Parameters
Notes
Tools (web search, code interpreter, image generation) are billed only when actually invoked. Requests that include your own function tools use standard function calling, and the built-in tools are unavailable on those requests: a request cannot combine both at once.
Per-tool billing (usage.tool_usage)
When this model invokes built-in tools (web search, code interpreter, etc.) inside a single request, the response carries a normalized usage.tool_usage map alongside the token counts. The example below shows the shape — exact field names, units, and which tools appear can vary slightly per provider:
The tool counts are already factored into cost_usd — they are surfaced for transparency so you can audit per-tool billing. The field is omitted when no tools were invoked.
Machine-readable schema: GET https://api.empiriolabs.ai/v1/models/mistral-small-4.
