Open the project folder
From the MainPath Toolbox you open the project under Projects with the button for your tool, alternatively in the editor via File → Open Folder with ~/Documents/MainPath/<organization>/<project>. Always open the parent project folder so that backend, app, homepage, and local-configuration sit side by side.
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, MainPath extension doppelt-digital.application-platform shows a welcome page with all repositories, links to GitLab and documentation, and a start button for mp run-local.
Open a terminal
Open a terminal via Terminal → New Terminal and change into the repository; ls shows the folders:
cd backend
Start the application
mp 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; mp ports lists all ports. For Flutter apps you specify the target, such as mp run-local chrome or mp run-local ios-simulator; mp 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
mp doctor checks the tools; the MainPath Toolbox’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; further options of mp run-local are in Starting applications.
Once the application runs, an AI agent can make changes.