# Open and run your project

You open the project folder in the editor, start a terminal, run the application with ap run-local, and view it in the browser.

> Source: https://www.application-platform.com/en/docs/open-and-run/

## Open the project folder

From the setup app you open the project under **Projects** with the button for your tool, alternatively in the editor via **File** → **Open Folder** with `~/Documents/application-platform/<organization>/<project>`. Always open the parent project folder so that backend, app, homepage, and `local-configuration` sit side by side and `AGENTS.md` and `.cursor` point to `local-configuration`.

In the remote workspace you open VS Code in the browser via **Apps** on the workspace card or connect via remote desktop; the project folders are in the home directory.

In VS Code, Cursor, and Antigravity, the platform extension `doppelt-digital.application-platform` shows a welcome page with all repositories, links to GitLab and documentation, and a start button for `ap run-local`.

## Open a terminal

Open a terminal via **Terminal** → **New Terminal** and change into the repository; `ls` shows the folders:

```bash
cd backend
```

## Start the application

```bash
ap run-local
```

A backend first starts Docker services such as database, Mailhog, and PHPMyAdmin and then the development server, an app the development server of its stack with the values from the `env` files, a homepage Hugo or Astro on the repository's port.

The terminal shows the local address, such as `http://localhost:3000`; `ap ports` lists all ports. For Flutter apps you specify the target, such as `ap run-local chrome` or `ap run-local ios-simulator`; `ap devices list` shows the devices, and several applications run simultaneously in several terminals.

## View it in the browser

Open the address in the browser; many development servers pick up saved changes automatically, otherwise reload the page.

## Stop

Press **Ctrl+C** in the terminal, on a Mac with Control, not Command.

## If something does not start

`ap doctor` checks the tools; the setup app's developer setup installs missing ones. If a port is in use, stop the old process or Docker container; if a runtime is missing although installed, you are not in the repository folder with the matching `.tool-versions`. Your own values belong in `env/local.custom.env`, see [Environment variables]({{< relref "environment-setup" >}}); further options of `ap run-local` are in [Starting applications]({{< relref "workspace-ubuntu-dev-scripts" >}}).

Once the application runs, an [AI agent]({{< relref "work-with-ai-agents" >}}) can make changes.