Contributing to Cog

Thank you for considering contributing to Cog! There are different ways if contributing, and we appreciate all of them.

Source Repository

Cog’s source repository is hosted at

Development happens in the master branch, which must be always buildable.

Reporting Bugs

Please report bugs at — you can also browse the issues already reported, and in case someone has already reported your bug, do not hesitate to add additional information which may help solve it.

A general advice for bug reports is to mention the version of WebKit that you are using, and which steps can be followed to reproduce the issue.

Hacking on Cog


This project requires WPE WebKit, libwpe, and WPEBackend-fdo; and it is recommended to also have the libdrm, X11 and GTK4 development packages installed.

The easiest way of getting the dependencies installed is using your Linux distribution’s package manager to install their development packages. For example, on a Debian (or Ubuntu) system, the following command should be enough:

sudo apt-get install libwpewebkit-1.0-dev libwpe-1.0-dev


Clone the Cog repository and do the following:

  1. Change directory to the cloned repository.
  2. Create a build directory, and change into it. This is where the built files will be stored.
  3. Run CMake to generate configure the build.
  4. Then run Make to compile the binaries.

The following sequence of shell commands does the steps above:

git clone
cd cog
mkdir _build && cd _build
cmake ..

Congratulations, you just finished building Cog!


To run Cog it, change into your build directory, and run the following command:

COG_MODULEDIR=$PWD/modules ./cog

Cog will try to guess which platform plug-in to use depending on what it finds running in your system. If you want to manually indicate which one to load, use the --platform= command line option:

COG_MODULEDIR=$PWD/modules ./cog --platform=x11

Typical values are fdo or gtk4 if you are running a Wayland compositor, x11 if you are running the X Window system, and so on.

Creating and sending a patch

Pull requests should be also prepared to be merged onto the master branch, except when the changes specifically apply to a release branch (like cog-0.1) and do not apply to master. If the changes in a PR should be backported to a release branch, link the PR in this wiki page.