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

# Introduction

> The REST API exposed by screenjson-cli when run in server mode.

`screenjson serve` starts an HTTP server that wraps the same conversion, export, and validation engine as the CLI. Use it from applications, serverless functions, or a frontend that needs to convert a screenplay without shelling out.

## Start a server

```bash theme={null}
screenjson serve --host 0.0.0.0 --port 8080
```

Or with Docker:

```bash theme={null}
docker run --rm -p 8080:8080 screenjson/cli serve --port 8080
```

See [`screenjson serve`](/tools/cli/serve) for the full flag list.

## Base URLs

| Environment | URL                              |
| ----------- | -------------------------------- |
| Local       | `http://localhost:8080`          |
| Public demo | `https://api.try.screenjson.com` |

## Endpoints at a glance

| Method | Path        | Purpose                                                  |
| ------ | ----------- | -------------------------------------------------------- |
| `GET`  | `/`         | Service descriptor, queue metrics, endpoint catalogue.   |
| `GET`  | `/health`   | Health check with per-service status.                    |
| `GET`  | `/formats`  | List every supported format.                             |
| `POST` | `/convert`  | Upload a file, receive ScreenJSON.                       |
| `POST` | `/export`   | POST a ScreenJSON document, receive an exported file.    |
| `POST` | `/validate` | POST a ScreenJSON document, receive a validation report. |

Detail pages for every endpoint are generated from the [OpenAPI spec](https://github.com/screenjson/docs/blob/main/api-reference/cli/openapi.json) — see the **screenjson-cli endpoints** group in this sidebar.

## Request limits

* `/convert` and `/export`: **50 MB** request body.
* `/validate`: **10 MB** request body.

## CORS

The server emits a permissive policy:

```
Access-Control-Allow-Origin:  *
Access-Control-Allow-Methods: GET, POST, OPTIONS
Access-Control-Allow-Headers: Content-Type, Authorization
```

## Error shape

All 4xx / 5xx responses are JSON:

```json theme={null}
{ "error": "human-readable message" }
```

## Authentication

The vanilla server exposes no authentication. For production deployments, put it behind an API gateway (AWS API Gateway, Cloudflare, nginx) and enforce auth there, or use [Greenlight](/tools/greenlight/overview) which bundles bearer token auth.