Connect an app with a device key

A device key connects another app to your Ultrathink account without a password. The browser extension and the desktop app use one to save entries. With API access turned on, the same kind of key lets the API and the MCP server read and write your entries.

Make one key per app or computer. Then if you stop using one, you can revoke its key and nothing else is affected.

Create a key

1. Open Ultrathink and go to Settings > Device keys. It is in the Config group of the Settings list.
2. Under New key, type a Device name, such as “Work laptop” or “Chrome at home”.
3. Click Create key.
4. The key appears once, under New device key created. Click the copy button next to it.
5. Paste it into the app you are connecting (see below).

The key is shown only this once. Copy it before you click Dismiss or leave the page. If you lose it, create a new key and revoke the old one.

You need a verified email to reach Settings, so verify first if you have just signed up.

Your keys

Every key you have made is listed under Your keys, with:

• its name and the first few characters of the key;
• when it was created and when it was last used;
• an API label if API access is on, saying read only or read and write.

Each row has two buttons: API settings and Revoke key.

Revoke a key

1. Click Revoke key on the key’s row.
2. Confirm with Revoke.

Any app using that key stops being able to save straight away. A revoked key cannot be turned back on. To reconnect the app, create a new key.

API access (Pro)

API access lets other tools, such as your own code, a ChatGPT custom GPT or Claude Code, use the key. It needs the Pro plan.

1. Click API settings on the key’s row.
2. Switch on API access.
3. Choose Permissions:
   • Read only: the tool can search and read your entries, but cannot save or change anything.
   • Read and write: the tool can also add, update and delete entries.
4. Add a Description if you want a note of what uses the key. It saves when you click away.

A key with API access switched on and Read only permission cannot save from any app, including the browser extension and the desktop app. Keep separate keys for capture apps and for API tools, or choose Read and write.

Where the key goes

Browser extension

1. Right-click the Ultrathink icon in the browser toolbar and choose Options.
2. Under Connect to webapp, paste the key into Device Key.
3. Click Save.

The extension keeps the key in this browser only. Each browser you use needs its own key. Full steps are in Browser extension: install and connect.

Desktop app

1. Copy the key.
2. Click the Ultrathink icon in the system tray (Windows) or the menu bar (Mac).
3. Choose Set Device Key from Clipboard.

A notification confirms the key was saved. There is no key field in the desktop app itself. Full steps are in Desktop app: install and connect.

iPhone

An iPhone app is coming soon. Until then, use the web app on your phone: sign in at tryultrathink.com, with no key needed. See On your phone.

API and MCP server

Send the key in the Authorization header of every request:

Authorization: Bearer YOUR_DEVICE_KEY

The key needs API access switched on, and your account needs Pro. See API: getting started and MCP server.

Keeping keys safe

• Treat a key like a password. Anyone who has it can save to your account, and with API access they can read your entries too.
• Ultrathink stores only a scrambled (hashed) form of each key on its servers, which is why the full key cannot be shown again.
• Give each key a clear name, so you know which one to revoke if a laptop goes missing.
• Revoke keys you no longer use.

Troubleshooting

More help is on the Troubleshooting page.