Mephisto Installation

Get an XPI package

If you don’t want to build your own XPI package, download the most recent package from GitHub on:

Make your own package

If you prefer or need to build your own XPI package, you first need to install the Firefox Add-On SDK and clone the Mephisto repository in a folder inside your SDK installation.

Mephisto repository can be found on: git://

You can then call cfx run or cfx test in a terminal to check that the add-on works fine.

Run cfx xpi to create an XPI file.

Install package

On Desktop

To install Mephisto on a desktop browser (you have full access to UI), simply drag the XPI file on your browser window.

On Server

Installing Mephisto without access to Firefox UI is a bit more complicated.

  • Create a folder name in the extensions folder of your Firefox profile,
  • Unzip the XPI file directly in the created folder,
  • Start Firefox.

On a server, you’ll need to start Firefox in a X server. It works fine with Xvfb.


Mephisto provides the following settings:

  • extensions.mephisto.serverPort: HTTP server port (default 9000)

You can set these settings in the user.js file in your profile. For example:

user_pref("extensions.mephisto.serverPort", 9000);