VS Code Remote Agent Browser Preview: How to Check Your App

A coding agent says your development server is running. You open its localhost link and see a blank page. Before asking the agent to rewrite anything, check which machine is serving the app and which machine your browser is trying to reach.

The VS Code remote agent browser preview gives you a way to open a web app from the host running your agent session. Microsoft announced it in the November 4 stable release of VS Code 1.145. In a supported remote session, enable the browser proxy and open the app’s original localhost URL inside the Agents window. Keep the server log handy so you can confirm the preview is showing the app you intended to review.

Check whether the preview fits your setup

The feature is in preview even though the editor release is stable. Microsoft’s VS Code 1.145 release notes describe routing the integrated browser through the remote agent host. Use the remote agent sessions guide to identify your connection. VS Code documents support for SSH, Tunnel and WSL connections in the Agents window. An agent chat running on your own laptop and a session connected to a remote host can look similar, so confirm which session owns the running server before comparing results.

This guide focuses on reviewing a development app in your own trusted workspace. Use synthetic data and a disposable test account if the flow needs a login.

Open the app from the remote session

1. Open the remote session in the Agents window and confirm the host and workspace.
2. Start the app using its existing development command. Record the exact scheme, host, port and path shown in the terminal. Keep the process running.
3. Enable workbench.browser.enableRemoteProxy and keep workbench.browser.dataStorage at default, as Microsoft describes in its remote sessions guide.
4. Open the original localhost address in the integrated browser for that session. The integrated browser documentation explains how the browser routes requests and how to check its connection.

Suppose the remote terminal reports http://localhost:5173/settings. That fictional example gives you a precise path to check. Open the exact address from your own server output. If you also run a copy of the project locally, make the build easy to identify with a harmless visible marker in your development branch.

Isolate a blank or unexpected preview

• Connection refused. Confirm that the server is still running and that its port matches the preview URL. Check the startup output for a crash or a fallback port.
• Wrong app or stale page. Check the host and workspace again. Then compare a visible build marker with the branch you are reviewing. A familiar screen can hide the fact that another process is serving the page.
• Page opens but data is missing. Check the browser’s network error and the app logs. Record which request failed and whether the development API is running before changing the UI.
• Preview is unavailable. Check the installed release, connection type and relevant workspace or organization settings against Microsoft’s documentation.

Change one variable at a time. If you change the port, restart the server and switch sessions together, a working page tells you little about which change fixed it.

Give the agent one observable check

After confirming the page yourself, use Share with Agent if you want the agent to interact with the page. Start with a short, reversible task. For example: “On the local development settings page, open the notification panel and report whether its heading appears. Stop before saving.” The instruction names a page, an expected result and a stopping point.

Ask for the actual result and any visible error. Compare it with what you see in the preview. Keep the preview task separate from a merge decision. TechPulse’s pull request review guide explains how to follow checks to their evidence.

Record enough for someone else to reproduce it

A useful review note contains the workspace or branch, the development URL, the action, the expected result and what you observed. Leave out credentials and private host details from public notes. If the app needs a particular fixture or account state, describe the safe test setup. That context gives the next reviewer a way to reproduce the result when the remote process is gone.

Prepared with AI assistance. This guide is based on Microsoft’s release notes and documentation. Examples are illustrative. Read the TechPulse editorial policy.