I'm not sure if this is a glitch on my end I didn't see an answer to online or if this is in the works or something, but I'm not seeing anything about it online. I want to be able to access my passwords without having to open the main application window.
I should be able to click a password field on a browser with my keepassxc-browser plugin hooked up, then enter my master password and fill it in without ever having to open up keepassxc itself.
As of now, if I want to fill in a password, I have to open keepassxc, unlock it from there, go back to my browser, refresh the database, then finally click and select which password I want to fill, move back to my browser (as that action puts keepassxc's main window in the foreground), then finally enter into the website.
The current way this works makes the browser extension next to pointless.
See the Current Behavior section. This has been tested on KDE/Manjaro and macOS Mojave, and Firefox (macOS, Linux), ungoogled-chromium (Linux), and Chrome (macOS)
KeePassXC - 2.3.4-1
KeePassXC-Browser - Chromium-1.3.2, Firefox-1.3.2, Chrome-1.3.2.
Operating system:
Browser:
The KeePassXC desktop application is required to be running when you are using the browser extension. The philosophy behind this project is to do and store as little as possible in the browser itself. This is a security measure and ensures your data is protected at all times.
To lessen the burden of using the browser extension I recommend that you enable the following setting:

Alternatively, you can enable "Remember this decision" when you allow access to a particular entry.
I do agree that the UX could be a little more seamless, this is something we are actively working on over the next couple of months.
It would be nice if the extension could directly read/write the database file (although not sure if that works with the WebExtensions API at all). Alternatively it would be cool if the extension could launch KeePassXC headless (or in the background at least).
For the moment I just don't use this addon, but instead manage credentials manually via KeePassXC and let Firefox store the credentials.
Accessing the database directly from the extension would need an additional library for reading KeePass databases. That would be quite a large job, and please note that there are already extensions which does this.
Another solution would be to use keepassxc-cli directly from the extension (meaning native messaging sends commands to the cli interface instead of keepassxc-proxy) with a master password. But this approach I haven't even tried yet even if it could work.
For the moment I just don't use this addon, but instead manage credentials manually via KeePassXC and let Firefox store the credentials.
Whaaaa?
Most helpful comment
The KeePassXC desktop application is required to be running when you are using the browser extension. The philosophy behind this project is to do and store as little as possible in the browser itself. This is a security measure and ensures your data is protected at all times.
To lessen the burden of using the browser extension I recommend that you enable the following setting:
Alternatively, you can enable "Remember this decision" when you allow access to a particular entry.
I do agree that the UX could be a little more seamless, this is something we are actively working on over the next couple of months.