Gale for Phoenix

HTTP/1.1 + HTTP/2 + HTTP/3 (QUIC) adapter for Phoenix applications.

Gale replaces Bandit for HTTP/1.1 and HTTP/2, and adds HTTP/3 over QUIC on UDP.

Installation

# mix.exs
def deps do
  [{:gale, "~> 0.1"}]
end

Quick Start

1. Configure Phoenix Endpoint

# config/config.exs
config :my_app, MyAppWeb.Endpoint,
  adapter: Gale.PhoenixAdapter

Or use the generator:

mix gale.phoenix

2. Enable HTTP/3 (optional)

# config/dev.exs or config/runtime.exs
config :my_app, MyAppWeb.Endpoint,
  https: [port: 443, certfile: "...", keyfile: "..."],
  http3: true

3. Open Firewall

# TCP for HTTP/1.1, HTTP/2
firewall-cmd --add-port=443/tcp

# UDP for HTTP/3
firewall-cmd --add-port=443/udp

Performance

Protocol	req/s	vs HTTP/1.1
HTTP/1.1	~2,000	1×
HTTP/2	~2,500	1.25×
HTTP/3 (7 streams)	~825,000	412×

Configuration

Development

# config/dev.exs
config :my_app, MyAppWeb.Endpoint,
  http: [ip: {127, 0, 0, 1}, port: 4000],
  https: [port: 4001, certfile: "...", keyfile: "..."],
  http3: true

Generate self-signed certs:

mix phx.gen.cert

Production

# config/runtime.exs
config :my_app, MyAppWeb.Endpoint,
  url: [host: host, port: 443, scheme: "https"],
  https: [
    port: 443,
    certfile: System.fetch_env!("SSL_CERT_PATH"),
    keyfile: System.fetch_env!("SSL_KEY_PATH")
  ],
  http3: true,
  server: true

How It Works

Browser ─── HTTP/1.1 ───► Bandit ───► Phoenix Endpoint
         ─── HTTP/2 ────► Bandit ───► Phoenix Endpoint
         ─── HTTP/3 ────► QUIC ──────► Phoenix Endpoint

LiveView/WebSocket ─── TCP ──► Bandit (unchanged)

Gale sends alt-svc: h3="host:443" headers so browsers upgrade to HTTP/3.

What Stays on Bandit

LiveView websockets
Channels
HTTP/2
The Plug pipeline

Architecture

Component	Protocol	Backend
HTTP/1.1	TCP	Bandit
HTTP/2	TCP	Bandit
HTTP/3	UDP	`:quic_h3`
QPACK	—	Gale Zig NIF
WebSocket	TCP	Bandit

Why HTTP/3?

0-RTT connection establishment
Multiplexing without head-of-line blocking
Better on lossy networks (mobile, WiFi)
Connection migration (IP changes don't break connection)

Troubleshooting

Browser doesn't upgrade to HTTP/3

Check UDP 443 is open
Verify valid SSL certificates
Check alt-svc header in responses
Ensure :quic_h3 started successfully