Re:Flex Server

Re:Flex is a lightweight, self-hosted, privacy-first messaging server written in Go with E2EE support and WebSocket real-time gateway.

Features

• Dual Authentication: Register/login with Email (RFC5322) OR Phone number (E.164 format).
• Public Key Binding: Stores Ed25519 or Curve25519 public keys during registration for End-to-End Encryption (E2EE).
• Embedded SQLite: Zero-dependency database using modernc.org/sqlite.
• Real-time WebSocket Gateway: Authenticated /ws endpoint supporting ping/pong heartbeat and JSON frame messaging.
• Dockerized: Multi-stage Dockerfile and Docker Compose with volume persistence.

---

API Endpoints

Auth Endpoints (/api/v1/auth)

POST /api/v1/auth/register

Register a new user with an email or phone number and upload their E2EE public identity key.

Request:

{
  "username": "alice",
  "identifier": "alice@example.com", // or "+14155552671"
  "password": "strongpassword123",
  "public_identity_key": "MCowBQYDK2VwAyEA..."
}

Response (201 Created):

{
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  "user": {
    "id": "c620456c-0e78-43db-b864-4424ff433230",
    "username": "alice",
    "identifier_type": "email",
    "identifier_value": "alice@example.com",
    "public_identity_key": "MCowBQYDK2VwAyEA...",
    "created_at": "2025-01-01T00:00:00Z"
  }
}

POST /api/v1/auth/login

Authenticate with email or phone number + password.

Request:

{
  "identifier": "alice@example.com",
  "password": "strongpassword123"
}

Response (200 OK):

{
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  "user": { ... }
}

GET /api/v1/users/:username/keys

Fetch a user's public identity key for initiating E2EE sessions.

Response (200 OK):

{
  "username": "alice",
  "public_identity_key": "MCowBQYDK2VwAyEA..."
}

---

WebSocket Gateway (/ws)

Connect with a JWT token passed via query parameter or Authorization header:

• ws://localhost:8080/ws?token=<JWT_TOKEN>
• Or Header: Authorization: Bearer <JWT_TOKEN>

WebSocket Frame Format

{
  "type": "ping" | "message" | "ack" | "pong",
  "payload": {}
}

---

Running Locally

1. Requirements

• Go 1.22+

2. Run

go run ./cmd/reflex-server

3. Run Tests

go test ./...

---

Running with Docker Compose

docker compose up -d

The server will run on port 8080, saving SQLite data to ./data/reflex.db.