This page was last updated in 2021-01.

So you want to start work on I2P? Great! Here's a quick guide to getting started on contributing to the website or the software, doing development or creating translations.

Not quite ready for coding? Try getting involved first.

Get to Know Java

The I2P router and its embedded applications use Java as the main development language. If you don't have experience with Java, you can always have a look at Thinking in Java.

Study the how intro, the other "how" documents, the tech intro, and associated documents. These will give you a good overview of how I2P is structured and what different things it does.

Getting the I2P code

For development on the I2P router or the embedded applications, you need to get the source code:

Our current way: Git

I2P has official Git services and accepts contributions via Git at our own gitlab. Trac issues have also been migrated to Git issues. Two-way syncing of issues between Gitlab and Github is a work-in-progress.

  • Install Git.

    • The read-only mirror is also still available at github.

    Building I2P

    To compile the code, you need the Sun Java Development Kit 6 or higher, or equivalent JDK (Sun JDK 6 strongly recommended) and Apache ant version 1.7.0 or higher. If you go are working on the main I2P code, you can go into the i2p.i2p directory and run 'ant' to see the build options.

    To build or work on console translations, you need the xgettext, msgfmt, and msgmerge tools from the GNU gettext package.

    For development on new applications, see the application development guide.

    Development ideas

    See the project TODO list or the issue list on GitLab for ideas.

    Making the results available

    See the bottom of the licenses page for commit privilege requirements. You need these to put code into i2p.i2p (not required for the website!).

    Get to know us!

    The developers hang around on IRC. They can be reached on the Freenode network, OFTC, and on the I2P internal networks. The usual place to look is #i2p-dev. Join the channel and say hi! We also have additional guidelines for regular developers.

    Translations

    Website and router console translators: See the New Translator's Guide for next steps.

    Tools

    I2P is open source software that is mostly developed using open sourced toolkits. The I2P project recently acquired a license for the YourKit Java Profiler. Open source projects are eligible to receive a free license provided that YourKit is referenced on the project web site. Please get in touch if you are interested in profiling the I2P codebase.

    YourKit is kindly supporting open source projects with its full-featured Java Profiler. YourKit, LLC is the creator of innovative and intelligent tools for profiling Java and .NET applications. Take a look at YourKit's leading software products: YourKit Java Profiler and YourKit .NET Profiler.