# Contributing to Stellar Horizon
Thank you for considering contributing to Stellar Federation!
This guide will help you get started.
## Before you start
Before starting to work on a feature or fix, please start a discussion
on our mailing list at `~aurora/stellar-sdk@lists.sr.ht`. You can,
alternatively, open an issue on GitHub. This will help avoid the
unfortunate situation in which your patch is rejected.
### Security issues
Please do not report security issues on GitHub. Send the security report
to our security mailing list at `~aurora/security@lists.sr.ht`.
### Feature requests
* Briefly explain why is this change necessary. What's the use case?
* How does the API look like?
* How do you plan to implement it?
### Bug fixes
* Describe how to reproduce the bug. Optionally include code samples.
* How do you plan to fix it?
## Accept Developer Certificate of Origin
You must [sign off](https://git-scm.com/docs/git-commit#Documentation/git-commit.txt---signoff)
your Git commits to indicate that you agree to the terms of the [Developer
Certificate of Origin](https://developercertificate.org/).
This can be done using the `-s` flag on `git commit`.
## Commit messages
This project uses [conventional commits](https://www.conventionalcommits.org/en/v1.0.0-beta.2/).
Before opening a Pull Request, make sure to [rebase](https://git-scm.com/book/en/v2/Git-Branching-Rebasing)
your commits in a single one.
## Contributing Changes
You can [send your patch by email](https://git-send-email.io/) to
`~aurora/stellar-sdk@lists.sr.ht`. Alternatively, you can open a Pull
Request on GitHub.
## Changelog
Document your changes in the CHANGELOG, the format is based on the
[Keep a Changelog](https://keepachangelog.com/en/1.0.0/) format.