Harmony Server

An open-source, self-hostable Discord alternative. Download a single binary, run it, done.

Why Harmony?

Self-hosting a chat server shouldn't require a DevOps degree. Harmony is a single Go binary that gives you text chat, voice channels, and presence — no external database or configuration needed. Container images are also available if that's your preferred way to deploy.

./harmony-server
# That's it. SQLite database created automatically. Listening on :8080.

For larger communities, opt into PostgreSQL and Redis when you need them.

Features

• Text channels with real-time messaging over WebSocket
• Voice channels with a built-in SFU (Pion WebRTC) — no STUN/TURN setup needed
• Presence tracking — online, idle, do not disturb
• Zero-config by default — embedded SQLite, in-memory pub/sub
• Scales when you need it — swap in PostgreSQL + Redis via environment variables

Quick Start

# Run from source
go run cmd/main.go

# Or build and run
go build -o harmony-server cmd/main.go
./harmony-server

Scaled Mode (optional)

docker compose up -d postgres redis

HARMONY_DB_URL=postgres://harmony:password@localhost:5432/harmony?sslmode=disable \
HARMONY_REDIS_URL=redis://localhost:6379/0 \
./harmony-server

Architecture

Harmony follows a hexagonal architecture (ports and adapters). Domain logic has zero dependencies on frameworks or infrastructure — adapters plug in from the outside.

cmd/                              # Entry point, dependency wiring
internal/
  domain/                         # Core types, interfaces (ports)
  application/                    # Use cases / business logic (services)
  adapter/
    http/                         # REST handlers, router, middleware
    repository/                   # SQLite implementation (default)
    token/                        # JWT implementation
  config/                         # Environment-based configuration
migrations/                       # SQL migration files (goose)

Tech Stack

• Go with chi router (thin net/http wrapper)
• Gorilla WebSocket for real-time communication
• Pion WebRTC for voice/video SFU
• SQLite (default) / PostgreSQL (opt-in)
• Redis (opt-in) for pub/sub and presence at scale

Contributing

# Run tests
go test ./...

# Lint
golangci-lint run

The codebase is intentionally simple. No ORM, no magic — just interfaces, raw SQL, and straightforward Go. If you've been looking for a project where you can make a real impact without wading through layers of abstraction, this is it.

License

AGPL-3.0 — see LICENSE for details.