Hacktoberfest 2023

Join our biggest hackathon of the year as we celebrate the 10th iteration of Hacktoberfest! See the many ways you can support the open source community and contribute to Mattermost.

Hacktoberfest is here!

This year, Hacktoberfest is working towards a greener future. The iconic Hacktoberfest t-shirts have become digital badges, and trees are getting planted to reward great work in the open source community. Read more about Hacktoberfest 2023 in our Mattermost blog and sign up today.

Everyone gets a digital badge just by connecting their Github account. The first 100 participants to have their first PR/MR accepted will have a Mattermost tree planted in their name through Tree Nation, along with a Mattermost Tree Planter certification you can showcase on your Linkedin profile.

Claim Your Digital Badge

Why should I participate in Hacktoberfest?

Explore and learn new technical skills

By participating in Hacktoberfest, you will have the opportunity to explore new projects and challenges. You will be able to develop your existing technical skills and perhaps learn new ones!

Learn and contribute to a real-world project

Mattermost puts forward real-world projects to contribute to as part of Hacktoberfest. We want to enable you to contribute to a project that thousands of people use every day so that you can have a real impact.

Be a part of the open source community

Throughout Hacktoberfest you will work along-side other members of the open source community from around the globe. You’ll have the opportunity to discuss and meet other like-minded contributors and build your network.

Earn limited-edition swag!

Have the opportunity to earn legendary limited-edition Mattermost swag by contributing to the Mattermost project in one of many ways!

How can I participate in Hacktoberfest?

Contribute to the Code

Contribute to the Code

You can contribute to the core code of the Mattermost project in a number of ways. For example you could write an end-to-end test which can improve our testing coverage while learning how Mattermost works! Or you can build an integration and extend Mattermost. Or you could work on existing Help Wanted issues that are open for our community members.

Contribute Now

Participate in QA

Participate in QA

Work alongside our community code contributors by testing the PRs they submit during Hacktoberfest. Our internal QA analysts and SDETs will be available for any questions you may have. Should the PR you test be for a new feature, help write tests for it in the GitHub Test Management repo. (Swag spoiler alert! For the first time ever, there is custom QA swag that will be awarded to participants who make a valid contribution to QA during Hacktoberfest. This custom swag will be awarded together with any Mattermost swag you earn for your contributions. Get ready to make an impact and claim your swag! Click the “Join Channel” link below to chat with fellow staff and community QA folk.)

Join Channel

Provide Translations

Provide Translations

Help us improve the accessibility of Mattermost and make it available to everyone. There is always an opportunity to help us expand our localization and translate Mattermost to new languages.

Join Channel

Help Others Learn

Help Others Learn

Our developer docs is the place where all of our guides, code examples, and product images exist. Help us improve our documentation by testing the guides, fixing typos or making updates. Do you have an interesting topic to discuss? Write for our blog and share your thoughts with other developers!

Join Channel

The technology behind the Mattermost ecosystem

Back-end language

Front-end language

Front-end framework

Mobile framework




To start learning about the technology powering Mattermost, check out the developer setup guide in the contributor documentation. From there, you can explore the Mattermost monorepo.

Hacktoberfest 2022 highlights

Last year we spent the month of October in style celebrating Hacktoberfest with our seasoned veterans as well as newcomers to our open source community. We had several different opportunities for community members to participate with Mattermost and Hacktoberfest – and of course, earn swag!

Read more about our 2022 Hacktoberfest in our blog post.



Lead the effort to ensure that all of our product configuration settings docs were migrated from an older, less-readable/scannable format, to a new table-based format. He also ensured required metadata was in place for the configuration settings content was site-searchable via docs.mm.com


QA and Translations

A long-standing, engaged member of the QA community. He consistently took part in testing, UX surveys and new feature reviews.


General Support

Supported migrations, upgrades, and provided helpful insights in the community channel.