> ## Documentation Index
> Fetch the complete documentation index at: https://docs.omniall.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# ChatGPT (Chat Completions)

> OpenAI Chat Completions format on Omniall AI.

# ChatGPT (Chat Completions)

OpenAI **Chat Completions** format:

```http theme={null}
POST https://api.omniall.ai/v1/chat/completions
Authorization: Bearer sk-...
```

Use this for the classic `messages` chat schema and most OpenAI SDKs (`client.chat.completions.create`).

For the newer OpenAI **Responses** format, see [Responses](/api-reference/responses).

| Scenario | How |
| - | - |
| Text chat / stream | `messages` + optional `stream` |
| Image understanding | `content` parts with `image_url` |
| File / PDF analysis | `content` parts with `file` |
| Web search | `web_search_options` / search-capable models |
| Agent / tools | `tools` + `tool_choice` |
| Structured JSON | `response_format` |

Pick `model` from the [Model Square](https://omniall.ai/pricing) or `GET /v1/models`.

Official docs: [Chat Completions](https://platform.openai.com/docs/api-reference/chat)


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