Inkline does not collect, store, or transmit the content you approve. For email, that means the text, subject, and recipients. When you approve with Touch ID, only a SHA-256 hash of the content leaves your Mac. A hash cannot be turned back into the content.
Our notary keeps your Mac's public keys (the Touch ID signing key and the App Attest key Apple certified, with its usage counter) and the date you enrolled. That is the whole record for Inkline for Gmail. Each single-use nonce is deleted the moment it is spent, and no copy of the receipt or the hash is kept: the receipt lives only in the email's stamp link. The notary cannot read, reconstruct, or link the content you approve.
Touch ID is handled by macOS and the Secure Enclave. Inkline never receives fingerprint data or any biometric information, and has no way to.
When a recipient checks a receipt, the check runs entirely in their browser using the receipt in the link. The verifier page makes no network requests and we do not learn who verified what.
No analytics, trackers, or advertising SDKs. The extension and the verify page set no cookies. We do not monitor your browsing or collect behavioral data.
We do not sell, rent, or share any data. The Mac helper talks only to our notary, and recipients' mail clients load the small stamp image from our verify site. The developer console uses Clerk for sign-in, so Clerk holds your sign-in email and sets its session cookies.
When a company uses the Approval API, the notary stores what that product needs: the action text the person approved (it is shown to them and embedded in the receipt), the company's own reference for the person and an optional display name, the person's public key or passkey credential, the receipt, and webhook delivery attempts.
A stamp shows that the holder of an enrolled key approved that exact content, witnessed by our notary. It is not a guarantee about who wrote the words or the truth of their contents.
Questions: gigialcaraz38@gmail.com. If this policy changes, the date changes with it. Last updated: 10/18/2026.