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

# Multi-service apps

> Preview websites and API servers in one project, and how publish deploys them.

# Multi-service apps

Some projects run more than one process — for example a **website** and an **API server**.

<img src="https://mintcdn.com/mythex/uQE27QrCJJ-e4nfa/images/workspace.png?fit=max&auto=format&n=uQE27QrCJJ-e4nfa&q=85&s=edd1c9df5c54faf80feb0ad2f34f14e0" alt="Workspace — chat on the left, Preview or Code on the right" width="2880" height="1800" data-path="images/workspace.png" />

## Preview picker

When both kinds of services are running, Preview shows a menu grouped into:

* **Websites** — browser-facing apps
* **Servers** — APIs and backends

Pick the service you want to inspect. The address bar follows the active preview.

If only one service is running, the menu stays simple (no groups).

## Publish

Publishing snapshots the project. Container backends can deploy as Fly apps (including extra services when the run config defines them). You get **one live public URL** for the app people open — not a separate “staging vs production” toggle in Publish.

## Tips

* Ask the agent clearly: “add an API server and keep the Vite front end”
* Use [App Testing](/features/app-testing) against the live preview after big changes
* For Dockerfile backends, see [How the tech is chosen](/features/templates)

## Related

* [Preview and Code](/features/preview-and-code)
* [How to publish](/publish/how-to-publish)
* [API backends](/guides/api-backends)