Run your app and try it

5 minute read · Projects & Git

The Preview tab in Browser lets you use the app you are building while its conversation stays close by. Start the project, open Browser and select Preview, then test the thing you asked the agent to make.

• Start, inspect, stop and restart
• Give the agent reproducible feedback
• Keep background processes with the project
• Runtime and Browser controls

Start, inspect, stop and restart#

Open the project and review its detected start command, environment and preview address. Choose Start app, then follow the individual preparation and launch steps. A full-stack app may have both an API process and a frontend process; a running frontend alone can still show failed data requests.

Use the Browser icon in the project's toolbar and select the App preview tab. The app Preview and website tabs share one Browser panel and tab strip. Reload after a change, navigate through the app and reproduce the requested behavior. To stop local work, use the runtime controls for the relevant process. Reopening a prepared project should start its recorded commands again without repeating completed scaffolding.

For reference pages, open a website tab in the same Browser panel, using the address/search field. A standalone chat has website tabs without a project Preview tab. Opening a browser page does not start a project process. Website navigation accepts safe HTTP(S) URLs, pages have no Node access or Vortex app bridge, and browser login sessions are ephemeral.

Give the agent reproducible feedback#

Report what you clicked, what you entered and what happened. “Create article accepted the form, but the item disappeared after reload” lets the agent inspect the write and read paths. Include a preview image when layout is the problem. An image confirms appearance at that moment; saved data and a successful user flow need their own checks.

A project terminal provides interactive command output in the checkout. Keep it distinct from a remote SSH session. Starting the local app is not deployment, and a synchronized conversation does not transfer its running processes to another computer. See checks and publishing before exposing the app outside your machine.

The project terminal opens below the work area in its own card. Drag the divider in the gap above it to adjust its height. Arranging chats or moving the editor does not move the terminal's running process to another project.

The terminal's project picker, the project sidebar and the badges in Files and Source Control follow the active checkout. New local terminals start in that selected folder. An existing session retains its directory and running process when you browse another project; switching projects is not a cd command. Terminal height and split size carry across projects and worktrees in the same workspace and window, while the sessions themselves stay with their project.

For an isolated worktree, prepare and start its app in that working folder and configure the Preview address it actually serves. Creating the checkout does not copy a database or start another server. Background process definitions with automatic port selection can choose an available port on startup; review the actual address, environment and service connections before using the two copies together. See working-copy selection.

Keep background processes with the project#

An app may need an API server, a frontend dev server and a queue worker or WebSocket service. Configure each needed command in the project's runtime/background-process workflow with its working directory and environment. Reuse a suitable running service instead of starting duplicate servers on the same port.

Start the required processes and inspect their individual status and logs. For a queued mail test, verify that both the web app and its worker are running before submitting the form. For live updates, check the WebSocket service as well as the page. Stop a process you own through its control when finished; closing Preview does not necessarily stop a service.

Ask the agent for a bounded diagnosis when a process exits: “Read the worker's recent error and explain why it stopped. Keep the current database and other services unchanged.” A scheduled agent task is different from a persistent worker; it launches a conversation run when due. Local schedules covers their timing, approvals and interruption behavior.

Related guides: checking your app, project configuration.

Runtime and Browser controls#

For a saved-data feature, start the app, add a fictional record in Preview, reload and confirm the record remains. A green running indicator verifies the process state, not the correctness of the feature. See checks and publishing.