Mistral Small 4
by MistralReleased Mar 16, 2026
mistralai/mistral-small-2603- Reads images
- Calls tools
- Answers in a JSON schema
- Reasons before it answers
Mistral Small 4 is the next major release in the Mistral Small family, unifying the capabilities of several flagship Mistral models into a single system. It combines strong reasoning from...
- Input / 1M tokens
- $0.18
- Output / 1M tokens
- $0.72
- Context
- 262K
- Longest answer
- 210K
What it costs
What each call is charged to the token's AI credit.
| Billed for | You pay |
|---|---|
| Input tokens | $0.18 / 1M |
| Output tokens | $0.72 / 1M |
| Cached input, read | $0.018 / 1M |
A typical call
A short chat turn: 2,000 tokens in, 500 out.
- per call
- $0.0007
- calls per $20
- 28K
What it can do
From its listing. The router passes every field through.
- Reads imagesYes
- Reads files and PDFsNo
- Hears audioNo
- Calls toolsYes
- Answers in a JSON schemaYes
- Reasons before it answersYes
- Searches the webNo
- Caches long promptsYes
- Draws imagesNo
Call it
Any router key works, in the format your SDK already speaks.
import OpenAI from "openai";const ai = new OpenAI({ baseURL: "https://relayfor.si/api/v1", apiKey: process.env.RELAYFOR_ROUTER_KEY,});const reply = await ai.chat.completions.create({ model: "mistralai/mistral-small-2603", messages: [{ role: "user", content: "Welcome the 1,000th holder in one line." }],});Specifications
What its maker and providers list for it.
- Reads
- Text and Images
- Writes
- Text
- Context
- 262,144 tokens
- Longest answer
- 209,715 tokens
- Reasoning effort
- none to high
- Intelligence index
- 11.3 (#148 of 220 rated)
- Released
- Mar 16, 2026
- Moderation
- None
Request fields
The fields its providers accept, passed through as you send them.
- frequency_penalty
- include_reasoning
- max_tokens
- presence_penalty
- reasoning
- reasoning_effort
- response_format
- seed
- stop
- structured_outputs
- temperature
- tool_choice
- tools
- top_p
Questions
How much does Mistral Small 4 cost?
$0.18 per million input tokens and $0.72 per million output tokens, paid from the token's AI credit. A call of 2,000 tokens in and 500 out costs about $0.0007.
How do I call Mistral Small 4?
Make a router key for one of your tokens on the dashboard, point any OpenAI or Anthropic SDK at https://relayfor.si/api/v1 and send the model id mistralai/mistral-small-2603. The token's AI credit pays for each call.
How long a prompt can Mistral Small 4 take?
Up to 262,144 tokens of context, and up to 209,715 tokens in one answer.
Are my prompts stored?
No. The RFS Router passes each call through and keeps only its token counts and cost, for the token's usage page.
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