The Arch package installs this directory under /usr/share/keepassgo/browser-extension/. On Linux desktop builds, launching KeePassGO refreshes the user-scoped native messaging manifests for Firefox and for any installed Chrome or Chromium KeePassGO Browser extension ids it can discover from browser profiles.

manifest.firefox.json uses the fixed Firefox extension id browser@keepassgo.com
manifest.chromium.json is the Chromium/Chrome manifest template
background.js caches per-tab match state, updates the toolbar badge, keeps token-scoped approval state visible, and talks to the native messaging host com.keepassgo.browser
content.js fills username and password fields on the current page, keeps fills tied to the focused form when possible, and shows inline KeePassGO field affordances when matches exist
options.html stores the API token in browser extension storage

The extension sends the API token to the native host on each request. The bridge does not store the token on disk.

Quick extension-side checks:

node --test browser/extension/background.test.cjs browser/extension/content.test.cjs

Reproducible Chromium validation:

make browser-extension-validate

That command validates Firefox by default. Use make browser-extension-validate BROWSER=chromium for the Chromium harness.