Contributing to Sequin

July 11, 2025 · View on GitHub

Thank you for your interest in contributing to Sequin! This document provides guidelines for contributing to the project.

Development setup

Prerequisites

Elixir 1.18+
PostgreSQL 14+
GitHub CLI (gh)
Node.js (for frontend assets)
Go (only necessary for CLI development)

Getting started

Fork and clone the repository
Start PostgreSQL and Redis with docker compose
```
docker compose --profile databases up -d
```
If you encounter an error about the default PostgreSQL user "postgres" not existing, you can create the user with:
```
createuser -s postgres
```
Install Elixir, Erlang, and Node.js through asdf Install and configure asdf if you don't have it already: https://asdf-vm.com/guide/getting-started.html

On Mac, you can use Homebrew:
```
brew install asdf
```
Add the following to your shell configuration file (e.g., .zshrc or .bashrc) to configure asdf:
```
. /opt/homebrew/opt/asdf/libexec/asdf.sh
```
Now you can use asdf to install the necessary versions of Elixir, Erlang, and Node.js:
```
asdf plugin add erlang
asdf plugin add elixir
asdf plugin add nodejs
```
Run this in the root of the repository to use our .tool-versions file:
```
asdf install
```
Run the setup script
```
mix setup
```
Start the development server:
```
make dev
```

The app will be available at http://localhost:4000.

Sequin uses LiveView + LiveSvelte for its frontend. As a monolith, the entire app is available at http://localhost:4000.

Development workflow

Create a new branch for your changes
Make your changes
Run tests:
```
# Run Elixir tests
mix test
```
Push your changes and open a pull request
Run make signoff to verify your changes pass all checks

Signoff process

For external contributors

When you submit a pull request, GitHub Actions will automatically run a series of checks.

After your PR passes, we will review your changes and hopefully merge!

If you need to reach us sooner, the fastest way is through our Discord server or Slack community.

For core contributors

Core contributors with repository access should run the signoff script before merging:

# From the project root
./scripts/signoff.sh

This script:

Checks code formatting
Performs compilation with warnings as errors
Runs all tests
Performs linting and other checks
Updates the GitHub commit status with a signoff

Code style

Elixir: Follow the standard Elixir formatting (enforced by mix format)
TypeScript/JavaScript: Use Prettier (enforced by the signoff process)
Go: Use standard Go formatting (enforced by go fmt)
SQL: Use lowercase for keywords

Documentation

Update relevant documentation in the docs/ directory
Follow the style guide for documentation
Run the docs locally using make docs

Getting help

Join our Discord server or Slack community for questions and discussions
Open an issue for bugs or feature requests
Tag maintainers in your PR if you need help

License

By contributing to Sequin, you agree that your contributions will be licensed under the MIT License.