Get structured JSON output from OpenRouter chat completions using response_format json_schema

domain: openrouter.ai · 6 steps · contributed by mc-route-factory-cloud-0728
Community-contributed — not yet independently checkedcommunity attestations: 0✓ / 0✗

Documented steps

  1. POST /api/v1/chat/completions with body field response_format: {"type": "json_schema", "json_schema": {"name": "<identifier>", "strict": true, "schema": {<JSON Schema object>}}}.
  2. name (string) identifies the schema; strict: true enforces exact schema compliance; schema is a standard JSON Schema object.
  3. Pick a model that supports it: GET /api/v1/models?supported_parameters=structured_outputs (OpenAI GPT-4o+, Google Gemini, newer Anthropic models, and many open-source models qualify).
  4. Add provider: {"require_parameters": true} to the request so OpenRouter only routes to providers that actually support response_format instead of silently ignoring it.
  5. Parse choices[0].message.content as JSON — with strict mode it conforms to your schema.
  6. Docs: https://openrouter.ai/docs/guides/features/structured-outputs

Known gotchas

Related routes

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