A prompt, a reply, a question.

Requirements and availability

Tessera needs an Apple silicon Mac running macOS 14 or later. It is coming soon to the Mac App Store and is not on sale yet. The planned price is $19.99 USD, paid once, with no Tessera subscription and no Tessera account.

Do I need an API key?

Only to send directly. Direct sending uses your own API key for a supported AI provider, entered in Settings › Providers. Your provider account and its usage charges are separate from Tessera and are billed by the provider. The key is kept in the Keychain on this Mac and is sent only to that provider's fixed address. Before the first request to a provider, Tessera asks for your consent; you can revoke it in Settings › Providers.

The clipboard route needs no key. Copy the sanitized prompt (⇧⌘C) into any chat app, then choose Paste reply on the turn card to bring the answer back; Tessera restores its placeholders the same way. The copy is the prompt alone: the chat you paste it into keeps its own earlier turns.

How a turn works

1. Type or paste your prompt and press Scan (⇧⌘S). Tessera marks names, numbers and other sensitive values on your Mac.
2. Decide each mark. Tag or Shape replaces it, Not sensitive keeps it for this turn, Send as is discloses that one value. Add anything the scan missed.
3. Open the wire preview (⌘↩) and read the exact request. Send it with your key, or copy it.

To bring text in from another app, select it and choose Review with Tessera from that app's Services menu, or copy it and choose Prompt › Review Clipboard. Some apps do not offer Services; Review Clipboard works with any app you can copy from. Tessera reads the text only when you choose one of these.

What detection can miss

Three detectors run on your Mac: patterns with checksums, Apple's language analysis, and the optional on-device model. Detection can miss sensitive information, and a placeholder does not hide what the surrounding text may reveal. Before a request starts, Tessera checks it for protected values, values the session replaced and identifiers the pattern scan recognises, but those checks cannot find what was never detected. Read every wire preview before you send it. A provider keeps what it has already received.

The optional on-device model

The on-device model adds contextual suggestions to the scan. It is optional and is downloaded only after you agree: a 3.58 GB download from Hugging Face, and a Mac with at least 12 GB of memory. Tessera shows the size, licence, storage location and this Mac's fit before it starts. Download, pause, check or delete it in Settings › Model. Without it, scans use the patterns and Apple's language analysis only.

Locking and the vault

Your placeholder mappings and protected values are kept in an encrypted vault on this Mac, protected by its Secure Enclave. Lock (⌘L) closes the vault, clears visible plaintext and cancels requests. There is no recovery kit in this version: erasing the vault in Settings › Vault, moving to a new Mac or resetting the Keychain starts over. Deleting a session removes the real values behind its placeholders.

Firms and multiple seats

Once Tessera is on the Mac App Store, firms can buy seats in Apple Business Manager › Apps and Books at the App Store price. Licences are user-assigned.

Troubleshooting

Open Help › Tessera Help in the app for the full guide, including the checks each request passes and the keyboard shortcuts. If a send fails, check the key and consent for that provider in Settings › Providers, then read the message on the turn card. If you still need help, email us with your macOS version, Tessera version and what you were trying to do. Do not send prompts, replies, API keys or protected values.