OpenAI API vs OpenRouter

OpenAI API

Official OpenAPI document and an llms.txt index. Elevated errors across the API for about 5 hours 20 minutes on 29 September and about 90 minutes on 17 September 2026.

OpenRouter

Public OpenAPI document, llms.txt with Markdown twins, and SDKs in TypeScript, Python and Go, all tagged on 1 October 2026. No machine payment. USDC top-ups go to a prepaid balance.

OpenAI API

1. Build on the Responses API. Astra calls tools only there
2. Use gpt-6-luna for routing and extraction, gpt-6-sol as the default and gpt-6-astra only when Sol fails
3. Anything pinned to gpt-5* or o3* stops on 2026-12-11. Move before then
4. Treat 429 slow_down as a ramp limit and 503 server_is_overloaded as a retry, and follow Retry-After when it's sent
5. Prompts over 272K tokens cost double on input. Trim before you pay for it

OpenRouter

1. Set provider.data_collection: "deny" or provider.zdr: true when the prompt holds anything private
2. Pass a models list so a failed provider falls through to the next one
3. Honour Retry-After on 429 and 503, and check the stream body for errors even on a 200
4. Set max_price so a routed request can't land on an expensive provider
5. Free models allow 50 requests a day until $10 of credit has been bought. Check GET /api/v1/key for what's left