Free Models Router

Zero-cost routing with therouter/free

The Free Models Router selects an eligible free model automatically based on your request shape and required capabilities.

TypeScript

const response = await fetch('https://api.therouter.ai/v1/chat/completions', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer <THEROUTER_API_KEY>',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    model: 'therouter/free',
    messages: [{ role: 'user', content: 'Hello! What can you do?' }],
  }),
});

const data = await response.json();
console.log('Resolved model:', data.model);

Response shape

Check the response model field to see which free model handled the request.

json

{
  "id": "gen-...",
  "model": "upstage/solar-pro-3:free",
  "choices": [
    {
      "message": {
        "role": "assistant",
        "content": "..."
      }
    }
  ]
}

Operational limits

Free routes can have lower throughput and tighter rate limits than paid routes. Keep retries and graceful degradation enabled for production traffic.

Need a specific free model instead of randomized router selection? Use the:free varianton the model slug.