Every permission we use, listed.

The Chrome extension

Runs on mail.google.com, where it works in the compose window you're writing in, adds read ticks to your sent emails, and notices when a recipient replies in a thread you open (who and when, never what they wrote). It also runs on the MailViewed dashboard, only to pair with your account. It uses no Google API permissions at all: it never fetches or searches your mailbox, and only sees the Gmail page you have open. It talks only to MailViewed's own servers, authenticated with a token minted when you pair. Its other Chrome permissions are storage (its settings and pairing token), notifications and alarms (desktop alerts when someone opens or clicks), and scripting (to start itself in Gmail tabs that were already open when it installs or updates).

Signing in

Google sign-in shares your basic profile: name, email, photo. Nothing else — no offline access, no Gmail scope.

Compose (optional)

One permission, gmail.send, requested only when you connect Gmail. Compose uses it to send from your address, and so do individual copies for group emails (Pro). Send-only; can't read or modify anything. Revoke anytime at myaccount.google.com/permissions.