Matomo core - Maintaining Plugins

This guide applies to Matomo core developers. If you develop a plugin and want to share it as a contributor please check out the guide for distributing plugins.

How to add a new plugin

  • Get Matt or Thomas to create a new github repository under matomo-org. The name for the plugin usually starts with plugin- followed by the plugin name. You can for example ping us in our slack. We use *.x-dev as the main branch where * would be replaced by the latest major version of Matomo.
    • After creating the repository, we should also directly configure transifex. To do this,
    • go to Repository Settings -> Secrets
    • click on new repository secret
    • Enter the name TransifexUsername and as value the username from keypass for transifex
    • Enter the name TransifexPassword and as value the password from keypass for transifex
  • Push the code
  • Add the plugin's repository as a submodule to our main matomo repository git submodule add {http-plugin-github-address} plugins/{pluginname}
  • Edit .gitmodules and move the entry for this submodule before the comment at the bottom (see description of that comment)
  • It's expected that some core screenshots will fail and maybe also some integration or system tests as the plugin will be activated and the tests for this plugin run during core tests too. This is because we consider the plugins bundled w/ core to be tested this often (testing compatibility on every matomo change). Otherwise the tests would only run when the plugin changes, even though a change in core could cause problems.

New plugin checklist

  • The new plugin has a LICENSE file similar to
  • The same license is also defined in plugin.json
  • A descriptive description and useful keywords are configured in plugin.json. Same for other values in the plugin JSON file.
  • If any possible screenshots are defined in the screenshots folder.
  • If docs/ or docs/ are not needed then delete them

Work on a premium plugin

  • Clone the plugin you want to work on into the plugins folder. Use the plugin name as the folder: plugin_SomeName -> SomeName
  • Create (or update if you already have it) a .gitignore file in your plugins folder and add the new folder. This .gitignore file is already ignored in the main .gitignore
  • Activate the plugin on the Administration dashboard, System > Plugins page
  • You can create branches, PRs inside this plugin folder

Maintaining plugin FAQs

How do I fix the error "Some Screenshots are not stored in LFS"?

The error might look like this:

1) Piwik\Tests\Integration\ReleaseCheckListTest::test_screenshotsStoredInLfs
   Some Screenshots are not stored in LFS: plugins/YourPluginName/tests/UI/expected-screenshots/Filename.png
   Failed asserting that an array is empty.

You can fix this issue using these steps:

  • cd plugins/YourPluginName
  • git rm tests/UI/expected-screenshots/*.png
  • Add tests/UI/expected-screenshots/*.png filter=lfs diff=lfs merge=lfs to the file .gitattributes in your plugin
  • git add tests .gitattributes
  • git commit -m 'Remove screenshots'
  • Add the expected UI test files again
  • git add tests
  • git commit -m 'Add screenshots using LFS'
  • Then update the submodule in core

Get travis to use LFS

To get travis to checkout the screenshots correctly and use LFS you will need to add/change the .travis.yml within your plugin like this (eg see this file):


  - if [[ "${TEST_SUITE}" == "UITests" ]]; then git lfs fetch; git lfs checkout; fi

And you need to create a file tests/travis/before_install.after.yml in your plugin with the following content (eg see this file):

- if [[ "${TEST_SUITE}" == "UITests" ]]; then git lfs fetch; git lfs checkout; fi