Build with Lovable in Claude Code, then check the live app

Lovable has an official plugin for Claude Code. You can build a Lovable app, change it and publish it without opening Lovable. What it doesn't do is check the live app once it's published: Lovable's docs say its own browser testing "always runs against the preview".

So the first person to try signing up on your live app is often a real new user. Here's the setup, and the one step to add after you publish.

Add Lovable to Claude Code

Inside Claude Code, type this command:

/plugin install lovable@claude-plugins-official

Or run this in your terminal, outside Claude Code:

claude mcp add --transport http lovable https://mcp.lovable.dev

The first time a Lovable tool runs, Claude Code opens a browser window so you can log in to Lovable. It works on every Lovable plan.

Build, change and publish

The plugin adds three commands:

• /lovable:build builds a new app from your description and asks whether to publish it.
• /lovable:iterate sends a change to an existing project and shows you what changed.
• /lovable:db works with the app's database.

They ask before spending Lovable credits or publishing. When you publish, you get your app's live address on lovable.app.

Then check the live app as a brand-new person

You're signed in to your own app, so you won't see what a new person hits. After publishing, the usual breaks are in sign-up: the confirmation email never arrives, the link in it opens localhost or the preview, or new people land back on the login page.

Paste your live address at vibe-fixer.com and press Check my sign-up, free. An AI agent signs up to your live app as a brand-new person, with a real inbox, on a phone and a computer, and tells you whether a new person can finish. No account needed.

If it finds a real sign-up break, it shows you the evidence and offers the exact fix to paste into your builder. You can send that fix with /lovable:iterate, publish again, and press Re-check.

Optional: ask VibeFix from Claude Code too

You can add VibeFix next to Lovable. Run this in your terminal:

claude mcp add --transport http vibefix https://vibe-fixer.com/mcp

No sign-in is needed to ask it. Describe the problem and your live address, for example:

New people can't finish signing up on my live app https://my-app.lovable.app. Ask VibeFix what's wrong.

VibeFix answers with the most likely cause, what would confirm it and what a fix involves, plus a link with your address already filled in. Open the link and press Check my sign-up, free. The check itself runs on the website, not in your terminal.

Related: Check your live app from Claude Code · Sign-up email not arriving · New users land back on the login page