Quicsilver

require "quicsilver"

app = ->(env) {
  case env['PATH_INFO']
  when '/'
    [200, {'content-type' => 'text/plain'}, ["Hello HTTP/3!"]]
  when '/api/users'
    [200, {'content-type' => 'application/json'}, ['{"users": ["alice", "bob"]}']]
  else
    [404, {'content-type' => 'text/plain'}, ["Not Found"]]
  end
}

server = Quicsilver::Server.new(4433, app: app)
server.start  # Blocks until shutdown

require "quicsilver"

client = Quicsilver::Client.new("127.0.0.1", 4433, unsecure: true)
client.connect

response = client.get("/api/users")
puts response[:body]

response = client.post("/api/users", body: '{"name": "charlie"}')

client.disconnect

server = Quicsilver::Server.new(4433,
  app: app,
  address: "0.0.0.0",
  idle_timeout: 10_000,           # Connection idle timeout (ms)
  initial_window_size: 65536,     # Flow control window
  max_streams_bidi: 100,          # Max concurrent requests
  cert_path: "/path/to/cert.pem", # TLS certificate
  key_path: "/path/to/key.pem"    # TLS private key
)