Usage

First, before you can use these extensions, you need a browser that is built with MOZ_REQUIRE_SIGNING="".

Here is a non-exhaustive list of these:

Then set xpinstall.signatures.required to false in either user.js or about:config.

Installation

Once you have a browser that supports unsigned extensions, follow the instructions for your platform.

Nix (with flakes and home-manager)

First, add the github:firefox-extensions-declarative/firefox-extensions-declarative flake to your flake inputs.
Now, you can use the extensions in you home-manager configuration like so:

# Example with surfingkeys-declarative
{
  programs.firefox.profiles.nix = {
    extensions.packages = [
      inputs.firefox-extensions-declarative.packages.${pkgs.stdenv.hostPlatform.system}.surfingkeys-declarative
    ];
  };
  programs.firefox.policies = {
    "3rdparty".Extensions."surfingkeys@brookhong.github.io" = {
      showAdvanced = true;
      snippets = builtins.readFile ./surfingkeys.js;
    };
  };
}

You can also get the extension ID by getting .extensionId on the extension package.

Nix (home-manager with alternative input pinners)

Add the equivalent of github:firefox-extensions-declarative/firefox-extensions-declarative to your pinner, then import the repo’s default.nix package set like this:

let
  firefox-extensions-declarative = import sources.firefox-extensions-declarative {
    inherit pkgs;
  };
in
{
  programs.firefox.profiles.nix = {
    extensions.packages = [
      firefox-extensions-declarative.surfingkeys-declarative
    ];
  };
}

The package set is built with manual pkgs.callPackage entries from default.nix.

Build from source

Clone the extension you want to install and follow the build instructions in its reference.

To install an XPI, go to about:addons, click the button to the side of “Manage Your Extensions”, and click “Install from file”.