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

# Introduction

> Reference for the Assembly public API

## Welcome

The Assembly API lets you manage clients, companies, messaging, files, billing, and
more programmatically. The endpoints in this reference are generated directly from the
API's OpenAPI specification, so they always reflect the live contract.

## Authentication

All requests are authenticated with an API key sent in the `X-API-KEY` header.

```bash theme={null}
curl https://api.assembly.com/v1/me \
  -H "X-API-KEY: <your-api-key>"
```

Requests without a valid key return `401 Unauthorized`; a key lacking permission for the
requested action returns `403 Forbidden`.