The companion fills passwords from Whisper and codes from Fistbump. You sign in to Whisper in the companion itself, so passwords fill whether or not the app is open: your master password is used to unlock the vault inside the extension and is never sent anywhere. Codes come from an open Fistbump, which stays a separate sign-in on purpose — so your passwords and your second factor never open with one unlock.

Why these steps exist

The companion is not in the browser stores yet. Chrome and Edge only auto-install extensions from their own stores, so until those listings are approved the install is manual. The steps below are the same ones extension developers use every day — nothing here weakens your browser's other protections, and the companion itself cannot make network requests at all.

Chrome and Edge

Chrome

1. Download the Chrome build and unzip it — you get a folder called fiducia-companion. Keep the folder; deleting it uninstalls the extension.
2. Open chrome://extensions in the address bar.
3. Turn on Developer mode (top right).
4. Click Load unpacked and choose the unzipped folder.
5. Pin it: puzzle-piece icon, then pin next to “Fiducia companion”.

Edge

1. Download the Edge build and unzip it.
2. Open edge://extensions.
3. Turn on Developer mode (left sidebar).
4. Click Load unpacked and choose the unzipped folder.

Firefox

Release Firefox only keeps extensions signed by Mozilla, and the signed add-on is still in review. Until then Firefox can load the companion for one session at a time:

1. Download the Firefox build and leave it zipped.
2. Open about:debugging#/runtime/this-firefox.
3. Click Load Temporary Add-on… and pick the zip.
4. It stays until Firefox closes — re-load it next session, or wait for the signed add-on, which will install from this site permanently.

Safari

Safari extensions ship through the App Store inside a Mac app, so the companion for Safari arrives with the Mac App Store release — it cannot be side-loaded from here at all.

After installing

1. Unlock both apps

Open Whisper at whisper.fiduciatogether.uk and Fistbump at fistbump.fiduciatogether.uk each in a tab and unlock them.

2. Click the companion on a sign-in page

It shows which site it matched, and offers only the entries saved for that site.

3. Pick the entry yourself

Nothing fills on its own, ever. Filling happens when you pick an entry — that is deliberate, and it is your phishing check as much as ours.