Annotation for Developers


Our team is working hard to build products and services built on our principles. However, we can’t do this alone. The long term success of open annotation depends on contributions from a wide array of sources.

Including yours! Here’s how you can join the effort.


We code and collaborate on GitHub. Our primary repository is h, and we keep ideas in our product-backlog repository.

We have long-form discussions on mailing list:

We chat in a public channel on Slack that anyone can register for and join to meet contributors and community members, hang out, discuss the project, and get questions answered. There’s also a public forum, which is a less technical place for users to ask questions and discuss needs.

Check out our documentation for the h code base to learn about what we’ve built and how to use our public API.

You can follow our development progress on our roadmap. Many have contributed tools, plug-ins and integrations, like these examples.


Hypothesis is open source. We typically use the 2-Clause BSD License (aka the “Simplified BSD License” or the “FreeBSD License”).

If you’re ready to dive in, check out our contributor guide which details our work-flow, conventions, and explains our contributor license agreement.