# Request formats

> Part of the ChinaAPI documentation. HTML: https://dash.chinaapi.ai/docs/api/request-formats/

Three request formats cover the whole catalogue. One ChinaAPI key and one Base URL work across all of them, so send whichever one your client already speaks.

## /v1/chat/completions — OpenAI

Use with OpenAI SDKs, Cherry Studio, Cline, Open WebUI, and most tool clients.

## /v1/messages — Claude

Route Claude-style message payloads while keeping the same gateway key and quota controls.

## /v1/responses — OpenAI

Use with Codex and other clients built on the Responses API. The console marks which models accept it.

> [!NOTE]
> Gemini models only
>
> Native Gemini requests go to `POST /v1beta/models/{model}:generateContent`. Only `gemini-*` models offer it, and not all of them do — each model's entry in Models lists the formats it accepts. Everything else takes one of the three formats above.

Multi-turn Responses conversations point at an earlier reply with `previous_response_id`. If a follow-up comes back with `previous_response_not_found`, the earlier reply has not been lost: wait ten to twenty seconds and send the same request again rather than rebuilding the conversation from scratch.