When something is wrong

Your address did not open

When a check cannot open your address, the console says why:

If you are sure it is up, Check it anyway on the setup screen starts the free check regardless. Some sites turn a quick probe away but still serve a visitor.

It will not test localhost

The hosted console runs on our servers, so it cannot reach your computer, and it refuses private and reserved addresses. This is a security measure: a testing tool that opened them would be a way into the machine it runs on. There are two alternatives:

• Deploy a preview somewhere public (most hosts give each branch its own address) and test that.
• Run nth Labs yourself, where localhost means your own machine.

A preview asks for a password

Vercel’s Deployment Protection puts a sign-in in front of each preview, so a run lands on Vercel’s page instead of yours, and Check setup in Settings → Product says so. You do not have to turn protection off. In Vercel, create a secret under Project Settings, Deployment Protection, Protection Bypass for Automation, then add it in Settings → Variables with the name VERCEL_AUTOMATION_BYPASS_SECRET. It is only ever sent to your preview’s own address.

Trouble with pages behind your login

• Every finding is about your sign-in page. Your address sends a stranger to it, so it is all a signed-out check can see. Add a test account and the next run signs in first: Testing behind a login.
• A signed-in run behaves like a signed-out one. The sign-in failed. Press Check setup in Settings → Product: its Sign-in recipe line says what went wrong, often in your login page’s own words. Then fix the path, the email or the password in Settings → Sign-in.
• Your product only signs in with Google, single sign-on or a code. The console cannot sign in with those. Testing behind a login describes two alternatives.

A run only covered a few pages

A check tests the pages in Settings → Pages, and your first check starts with your home page and the pages it links to. Press Scan for pages there (Scan again if you have scanned before) to find the rest, or add a page the scan cannot reach yourself. Pages behind your login only turn up once a test account is saved and you scan again.

A message about your plan

• “This check uses AI.” On Free, the checks with AI (Site review, the simulated customers and the walks through your product) run once a month, as part of Check my site, with no card needed. On their own, or once this month’s full check is used, they wait for the next month or an upgrade, in Settings → Plan. Every other check keeps running.
• “You have reached… fair use for this month.” This month’s validations are used up, and the message gives the day they reset. For more now, buy a top-up or move up a plan in Settings → Plan. The free checks keep running.
• “Your last payment did not go through.” Your plan keeps working for 7 days while the card is retried. Press Update card in Settings → Plan.

You cannot sign in to nth Labs

• Too many wrong passwords. Five wrong attempts pause sign-in for a while, and each pause is twice as long as the last. It clears by itself.
• A forgotten password. Press Forgot password? on the sign-in page. When the console can send email, you get a reset link that works once and expires in 30 minutes. When it cannot, the page asks you to email support@nthlabs.dev from the address on your account, and we send you a temporary password.
• You signed up with Google or GitHub. Use the same button again. A Google or GitHub sign-in will not attach itself to an account made with a password: sign in with the password, then connect it in Settings → Account.

Missing screenshots or accuracy figures

• “The captures for this run are gone.” Deleting a run removes its screenshots. The finding stays, but its frames are gone, so the console has no picture to show.
• No accuracy figure is shown. The console shows one only after you have given enough findings a verdict, because a rate from fewer would mean little. Give some verdicts, especially Not a problem on the ones that were wrong.

If you run it yourself

These only apply to a copy of nth Labs on your own machine or your own server.

Run doctor first

node cli.cjs doctor

One browser pass that spends nothing. It checks that every page loads and lands where it should, that the sign-in works and that the file mappings resolve. It exits with an error when something is broken, and it reports most of the problems below.

“Executable doesn’t exist” when a run starts

The browser was never downloaded. npm install fetches the library, not the browser it drives:

npx playwright install chromium

A check stops and says there is no product

This is by design: no check guesses what your product is. Run node cli.cjs init, or set the product up in the console under Settings → Product.

Your own server will not start

On an address other people can reach, the console refuses to start until it has an owner account, and its log says REFUSING TO START. Set LABS_EMAIL and LABS_PASSWORD (at least 10 characters) and start it again. docs/DEPLOY.md in the repository has the rest.

A protected preview, from your own copy

Set LABS_BYPASS_TOKEN to Vercel’s bypass secret, or LABS_BASIC_AUTH to user:password for a preview behind a simple password, such as Netlify’s. Both are sent only to the preview’s own address and are never written down.

An imported session stopped working

Sessions expire. Sign in again in your own browser, export a fresh session and import it with node cli.cjs session import. node cli.cjs session status shows what is on file.

Still stuck

Write to support@nthlabs.dev with what you did and what came back. For a security issue, write to hello@nthlabs.dev and see the security page.