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Free · Mistral Small 4 + Mistral Nemotron

Free Mistral API.
No key. No subscription.

Mistral Small 4 119B — fast, free, no key. Plus Mistral Nemotron (Mistral × NVIDIA) as the second free option.

Try in 10 secondsSee all 6 waysWant Claude / GPT-5? Pay-per-call →
Quickstart · 10 seconds

Try it now.

No API key. No wallet. No signup. Paste this into any terminal — the response streams back from Mistral hosted free on NVIDIA, routed through BlockRun.

curl
curl https://blockrun.ai/api/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "nvidia/mistral-small-4-119b",
    "messages": [{"role": "user", "content": "Write a one-paragraph bio for an open-source maintainer"}]
  }'
See all 6 waysFull API reference →
Spotlight
Mistral Small 4 119B (Free)
nvidia/mistral-small-4-119b
Context
131K
Price
free
Best for
coding
Mistral Nemotron (Free)
nvidia/mistral-nemotron
Context
131K
Price
free
Best for
coding
Six ways to call it

6 ways to use Mistral free.

BlockRun is the access layer. Pick the surface that matches how you build — terminal, notebook, IDE, agent runtime — and the same free models work everywhere.

  1. 01

    cURL

    no key, no wallet, paste in any terminal

    Learn more →
    shell
    curl https://blockrun.ai/api/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "nvidia/mistral-small-4-119b",
    "messages": [{"role": "user", "content": "Write a one-paragraph bio for an open-source maintainer"}]
  }'
  2. 02

    Python SDK

    pip install blockrun-llm — or any OpenAI-compatible client

    Learn more →
    python
    # Works with the OpenAI SDK — no key required for free models
from openai import OpenAI

client = OpenAI(
    base_url="https://blockrun.ai/api/v1",
    api_key="not-needed-for-free-models",
)

response = client.chat.completions.create(
    model="nvidia/mistral-small-4-119b",
    messages=[{"role": "user", "content": "Write a one-paragraph bio for an open-source maintainer"}],
)
print(response.choices[0].message.content)
  3. 03

    ClawRouter

    smart router for OpenClaw / Claude Code — auto-picks free models when possible

    Learn more →
    shell
    # Install once
npm install -g @blockrun/clawrouter

# Then point any OpenAI-compatible client at the local proxy.
# ClawRouter routes to nvidia/mistral-small-4-119b (or the cheapest capable model)
# without changing your code.
  4. 04

    TypeScript SDK

    npm install @blockrun/llm — or any OpenAI-compatible client

    Learn more →
    typescript
    // Works with the OpenAI SDK — no key required for free models
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://blockrun.ai/api/v1",
  apiKey: "not-needed-for-free-models",
});

const r = await client.chat.completions.create({
  model: "nvidia/mistral-small-4-119b",
  messages: [{ role: "user", content: "Write a one-paragraph bio for an open-source maintainer" }],
});
console.log(r.choices[0].message.content);
  5. 05

    Franklin Agent

    the AI agent with a wallet — free OSS models for routine tasks, paid models on demand

    Learn more →
    shell
    # Install Franklin Agent
npm i -g @blockrun/franklin

# Run with this model
franklin start --model nvidia/mistral-nemotron -p "Summarize the README"
  6. 06

    Claude Code MCP

    20 tools for Claude Code, Cursor & ChatGPT — call any free model from inside your editor

    Learn more →
    shell
    # Add the BlockRun MCP server (Claude Code, Cursor, or ChatGPT desktop)
claude mcp add blockrun -s user -- npx -y @blockrun/mcp@latest

# Then call from inside the editor:
#   blockrun_chat(model="nvidia/mistral-nemotron", messages=[{role:"user", content:"…"}])
Trust / Defaults

We don't share
your data.

Your prompt goes to the AI provider you picked. Nothing else, nowhere else. No training, no retention beyond the request, no profile linking.

Read the privacy policyTerms →
We don't share your data
No training, no retention beyond the request. Your prompt is forwarded only to the AI provider you select.
No accounts, no KYC
Wallet in, prompt out. Pseudonymous by default — no email, no phone number, no identity documents.
Open-source SDKs, MIT
Read the code, audit the wire format, run it yourself. @blockrun/llm and blockrun-llm on npm and PyPI.
When free isn't enough

Want Claude, GPT-5,
or Gemini too?

No subscription. No monthly minimum. Pay per call in USDC via x402 — works the same endpoint, same SDK, same model IDs. Connect a wallet, top up $5, call any frontier model. No credit card.

See pay-per-call pricingGet started
FAQ

Everything you might
be wondering.

Which Mistral should I pick?
Default to Mistral Small 4 119B — it is the fastest free Mistral here and answers in a few seconds. Mistral Nemotron (Mistral × NVIDIA) is the alternative, though its NVIDIA deployment can take a while to wake up if it has been idle. Neither needs a key.
Is the Mistral API free for production use?
BlockRun routes free requests through NVIDIA's free tier with no per-call billing. Throughput is subject to NVIDIA's quota — for guaranteed SLA, switch to paid models with a wallet.
Do these support function calling?
Yes — they emit OpenAI-compatible tool_calls. Same wire format as paid models, just route through the free endpoint.
What happened to Devstral 2 / Mistral Large 3 675B?
Devstral 2 was pulled from NVIDIA's free upstream (404), and Mistral Large 3 675B stopped responding entirely as of 2026-07-20 — it had been degrading for weeks. Calls to either auto-reroute to a healthy free model via BlockRun's health gate, so requests still return 200. They come back automatically if NVIDIA restores them.