Set up the @bridge extension

The @bridge add-on is what puts AI inside Thunderbird — the @b button and the settings page. In most cases you don’t install it by hand:

Tip

The atbridge.ai installer adds the extension to Thunderbird for you. Use the manual steps below only if you’re sideloading the add-on, reinstalling it, or installing a specific .xpi you downloaded.

Install the add-on from a file

You’ll need the atbridge-extension-<version>.xpi file — download it here (it lands in your Downloads folder).

1. In Thunderbird, open the menu (☰, top-right) or the gear at the bottom of the activity bar, and choose Settings.

2. In Settings, click Add-ons and Themes — this opens the Add-ons Manager in a new tab.

3. Select Extensions in the left menu, then click the ⚙ gear at the top right of Manage Your Extensions.

4. Choose Install Add-on From File….

5. In the file picker, open your Downloads folder and select atbridge-extension-<version>.xpi, then click Open.

6. Thunderbird asks for permission — click Add. You’ll see “atbridge.ai was added”; click OK.

The @b button now appears in Thunderbird’s activity bar, and atbridge.ai shows under Enabled in the Add-ons Manager.

Note

Updating the add-on later? atbridge update-extension swaps in the newest .xpi for you — see the CLI reference. You can also reinstall manually with the same steps above.

Next steps

Open the @bridge extension settings Find the @b pane and the settings gear.

Connect your AI Add a provider key and start chatting.

Use the @bridge AI Chat Ask across every mailbox at once.

@bridge Skills Instant slash-commands over mail + calendar.