Common ways published v0 apps break
From v0's and Vercel's docs, and failures we've written guides for. Under each one, “Heedza sees this” means the problem stops a page from opening or removes its form, so you get an alert. Heedza only sees what a visitor sees before logging in, so it can’t see problems that happen after a form is sent.
- The preview and production see different environment variables. v0's docs: "The v0 preview window can only access variables from the Development environment" (v0: Vercel integration). Something can work in the preview and fail live, or the reverse, if a key is only set for one environment. Heedza sees this.
- Env changes need a new deployment. On Vercel, env changes "only apply to new deployments" (Vercel: Environment variables). Heedza sees this.
- Preview deployments aren't production. Working branches get preview deployments with their own URLs that "do not change the project's production URL"; Publish is what updates production (v0: Deployments). Heedza can’t see this.
- The build fails. v0 shows actions such as Fix Build or Fix CI for GitHub-backed projects (v0: Deployments). Heedza can’t see this.
- Stripe breaks after switching to live keys. One v0 user hit "Neither apikey nor config.authenticator provided" after moving to live mode (Vercel Community). See our guide. Heedza sees this if the payment page stops opening or loses its Pay button.
- AI routes time out. See Vercel 504 FUNCTION_INVOCATION_TIMEOUT on your AI feature. Heedza can’t see this.
- React hydration errors when server and browser render different HTML (Next.js: Hydration error). Heedza sees this.
What Heedza checks
Heedza works from the outside, on your public web address. There's nothing to install.
- Your key pages. We open your home page the way a visitor does, follow its links to your sign-up, log-in and payment pages, and check on a schedule that each one opens and shows its form or Pay button.
- Security checks. The free scan looks for secret keys in your page code and
.envor.gitfiles anyone can open. - Alerts. When a check fails, you get an alert (by email, or on paid plans also Slack, Telegram or a webhook (we send the alert to a web address you choose; for developers)) with a picture of the page and a fix written for v0, ready to paste into the v0 chat.
It never fills in forms, never logs in, never types a card number and never clicks Pay. So it can't tell you whether a log-in, email or payment works after the button is pressed.
It works the same for any vibe-coded app, whichever AI tool made it. Build v0 apps for clients? See Heedza for agencies: up to 30 client sites, with white label client reports and status pages on Business.
Fix it for me (Pro and Business)
Some alerts have a Fix it for me button. Nothing starts until you press it. Heedza then writes the fix and suggests it on GitHub (a pull request). Nothing changes in your app until you approve it, and you can undo it.
It works for a page Heedza checks that stopped working (such as sign-up, log-in or payment), a file that should not be public, and a security setting your site stopped sending. It needs your app’s code in a GitHub project (repository), with the Heedza GitHub app added to it. Other alerts come with a fix to paste into your AI tool. How Fix it for me works