> ## Documentation Index
> Fetch the complete documentation index at: https://client-integrations-api-dev.sequen.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> Introduction to the Sequen REST API principles, base URL, and authentication.

# Sequen API Overview

Welcome to the Sequen REST API reference. Our APIs allow you to integrate Sequen's powerful reinforcement learning-based personalization features into your applications.

## Base URL

All Sequen API endpoints are accessed via the following base URL:

```
https://api.sequen.com/v1
```

## Authentication

All requests to the Sequen API must be authenticated. We use API Keys for authentication. Include your API key in the `Authorization` header of your requests.

See the [Authentication guide](/api-reference/authentication) for details.

## Versioning

The API version is included in the URL path (`/v1`). Breaking changes will result in a new version number.

## Request Format

* Sequen APIs generally accept JSON-formatted request bodies for `POST`, `PUT`, and `PATCH` requests.
* Set the `Content-Type` header to `application/json`.

## Response Format

* Responses are returned in JSON format.
* Successful requests typically return a `2xx` status code.
* Client errors (e.g., invalid parameters, missing authentication) return a `4xx` status code.
* Server errors return a `5xx` status code.
* Error responses include a JSON body with `code` and `message` fields providing details about the error.

```json Error Response Example theme={null}
{
  "code": "invalid_parameter",
  "message": "Missing required field: 'userId'"
}
```

## Rate Limiting

API requests are rate-limited. If you exceed the limit, you will receive a `429 Too Many Requests` response.

{/* ## SDKs

While you can interact directly with the REST API, we recommend using our official SDKs for easier integration:

*   [JavaScript SDK](/sdks/javascript) (To be created)
*   [Python SDK](/sdks/python) (To be created)
*   [Java SDK](/sdks/java) (To be created) */}

Navigate through the API sections using the sidebar to explore specific endpoints.