Routing

Set preferences

The provider field sets execution-selection rules for one request. Treat it as policy, not a promise of a specific internal route.

For tasks with mandatory properties, require the relevant parameters explicitly instead of silently lowering quality.

{
  "model": "openai/gpt-5.6-sol",
  "messages": [{"role": "user", "content": "Classify this support ticket."}],
  "provider": {
    "order": ["provider-a", "provider-b"],
    "allow_fallbacks": true,
    "require_parameters": true
  }
}

Useful constraints

• order sets the priority of allowed options.
• allow_fallbacks defines whether a request can move to an alternative.
• require_parameters helps reject a route that cannot satisfy the declared contract.

Observability

Keep the selected model, timing, status, and spend in your own trace. Do not present internal routing details to a user as fact when they are absent from the response.

When options are exhausted, respond predictably: return the original cause and offer a retry with compatible configuration.