## TL;DR
Delete the stale storage state file and re-run your auth setup step to mint a fresh one; storageState is a snapshot, not a live session, and it goes stale like any login. In CI, regenerate it on every run instead of committing a long-lived file. If logins expire mid-suite, shrink the gap between auth setup and the tests that need it.

## Problem
The saved `storageState` file (cookies plus local storage) has expired, so tests start logged out and fail on redirects to the login page.

## Steps
1. Delete the stale file (default `playwright/.auth/user.json`) and re-run the setup project: `npx playwright test --project=setup`. Expected: a fresh storage state file is written with a new timestamp.
2. Confirm the file is fresh and non-empty, then run one dependent test. Expected: the test starts authenticated with no login redirect.
3. In CI, make the setup project a dependency of the test projects and never cache the auth file across runs. Expected: every CI run mints its own auth state.
4. If your session lifetime is short, run auth setup in the same job immediately before the tests. Expected: no test starts with an expired session.

```js
// playwright.config.js
module.exports = {
  projects: [
    { name: 'setup', testMatch: 'auth.setup.js' },
    { name: 'chromium', dependencies: ['setup'] },
  ],
  use: { storageState: 'playwright/.auth/user.json' },
};
```

## When to use
- Tests that passed yesterday now redirect to login.
- The storage state file is days or weeks old.
- CI reuses a cached auth file across runs.

## When not to use
- Designing auth from scratch (setup project structure is a different topic).
- The login flow uses MFA or SSO that needs human interaction.
- Your tests authenticate via API tokens rather than browser storage.

## Tool compatibility
- Playwright 1.40 through 1.5x, `@playwright/test` runner.
- Project dependencies (`dependencies: ['setup']`) are available in all recent versions.

## Variant phrasings
### playwright auth state expired between runs
Same cause and fix: regenerate the storage state, stop caching it.
### storageState login redirect after some days
The saved session aged out; re-run the setup project.

## Why it happens
storageState captures cookies and local storage at a point in time. Session cookies expire on the server schedule regardless of the file, so a state saved last week logs you out today. Caching the file in CI makes the staleness permanent.

## Edge cases
- Setup passes but tests still log out: the `storageState` path in `use` does not match the file the setup wrote.
- Works locally but not in CI: CI may block third-party cookies, or the login needs a secret that is empty in the CI environment.
- Login needs MFA: use a seeded test account without MFA, or a static backup-code path for automation.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_MR6x9pfMVMfQE30_BnnzQQ