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

# Flatkey REST API: Endpoints, Auth, and Request Format

> Flatkey exposes an OpenAI-compatible REST API at https://router.flatkey.ai/v1. All requests require a Bearer token and target JSON over HTTPS.

The Flatkey API is a REST API that is fully compatible with the OpenAI API specification. Every request goes to `https://router.flatkey.ai/v1` — the same base URL for all endpoints, providers, and models. Authentication uses a Bearer token in the `Authorization` header.

## Base URL

```
https://router.flatkey.ai/v1
```

## Authentication

All requests must include your Flatkey API key as a Bearer token:

```
Authorization: Bearer sk-fk-your-api-key
```

Generate your API key in the [console](https://console.flatkey.ai/keys). See [Authentication](/api-reference/authentication) for full details.

## Request format

* All requests use **HTTPS**
* Request bodies must be **JSON** (`Content-Type: application/json`)
* Responses are JSON (or SSE for streaming)

## Available endpoints

| Endpoint                 | Method | Description                                  |
| ------------------------ | ------ | -------------------------------------------- |
| `/v1/chat/completions`   | POST   | Chat and text generation (OpenAI-compatible) |
| `/v1/responses`          | POST   | OpenAI Responses API (stateful multi-turn)   |
| `/v1/embeddings`         | POST   | Text embeddings                              |
| `/v1/images/generations` | POST   | Image generation                             |
| `/v1/models`             | GET    | List available models                        |

## OpenAI SDK compatibility

Because the API is OpenAI-compatible, you can use the official OpenAI Python or Node.js SDK with no changes to the request code — just set `base_url`:

<CodeGroup>
  ```python python theme={null}
  from openai import OpenAI

  client = OpenAI(
      api_key="sk-fk-your-api-key",
      base_url="https://router.flatkey.ai/v1",
  )
  ```

  ```javascript node theme={null}
  import OpenAI from "openai";

  const client = new OpenAI({
    apiKey: "sk-fk-your-api-key",
    baseURL: "https://router.flatkey.ai/v1",
  });
  ```
</CodeGroup>

## Versioning

Flatkey uses the same versioning scheme as the OpenAI API. The `/v1` path prefix is stable. When new OpenAI API versions are released, Flatkey adds support while maintaining backward compatibility with `/v1`.

## Rate limits

Rate limits are applied per API key. If you exceed the limit, you receive a `429 Too Many Requests` response. Contact [support@flatkey.ai](mailto:support@flatkey.ai) if you need higher rate limits for production workloads.

## Supported content types

| Content type        | Used for                                  |
| ------------------- | ----------------------------------------- |
| `application/json`  | All request bodies and responses          |
| `text/event-stream` | Streaming responses (when `stream: true`) |