Preview environments: every branch at its own address
When parallel agents work in different worktrees, you don’t need to start each dev server by hand and hunt for free ports to see their results. The Preview tab starts the server of the project and of every worktree on its own port and gives each an address named after its branch.
One address per branch
Each environment opens at http://<branch>.agentvera.localhost:<port>; the local proxy passes WebSockets through. The start command is found from the dev, start, serve or preview script in package.json, with a port flag added for Vite, Astro, Nuxt, SvelteKit, Remix, Next and Angular. Django’s runserver is detected too; otherwise a built-in static server serves index.html. You can also write your own command with a {port} placeholder.
- Start, restart, stop and logs.
- Open in the AgentVera browser or your system browser, or copy the address.
- With Vercel connected, the branch’s Vercel preview URL also shows on the environment card.
Visual comparison
Full-page screenshots of the pages you choose are taken at Mobile (375×812), Tablet (768×1024) and Desktop (1440×900); up to 6 sizes can be set. You set a baseline, later shots are compared with it pixel by pixel and changed pixels are marked in red. The default change threshold is 0.1% of pixels.
Have an agent test it
The test-with-agent button opens a Claude agent in that worktree with the AgentVera browser. It opens every page, resizes to each breakpoint, looks for overflow, broken layout, unreadable text, console errors and dead links or buttons, fixes what it can and reports back.
How to use it
- 1
Open the Preview tab on a project’s Details page; the project and its worktrees are listed.
- 2
Start an environment and open its address.
- 3
Save baseline shots, then compare with the baseline after a change.
Questions
Which projects does it work with?
Projects with a dev, start, serve or preview script in package.json, Django projects and static sites. For anything else you can write your own start command.
Which pages are screenshotted?
The pages you list in the preview settings; by default only the home page (/).
Which agent runs the test?
A Claude Code agent with the AgentVera browser, opened in that worktree.
Related features
Related terms:Git worktreeVisual regression testing
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