An MQTT 3.1.1 / 5.0 client.

The process that creates a client owns it: received messages and connection losses arrive in its mailbox, and when it exits the client disconnects.

{:ok, client} = StemMqtt.Client.new(host: "localhost", client_id: "sensor-1")
{:ok, %{session_present: false}} = StemMqtt.Client.connect(client)
{:ok, _reason_code} = StemMqtt.Client.subscribe(client, "sensors/#", qos: 1)
:ok = StemMqtt.Client.publish(client, "sensors/t", "21.5", qos: 1)

receive do
  {:stem_mqtt, id, {:message, %StemMqtt.Message{topic: topic, payload: payload}}}
  when id == client.id ->
    {topic, payload}

  {:stem_mqtt, id, {:disconnected, reason}} when id == client.id ->
    reason
end

Options

• :host (required), :port (1883), :client_id ("": the broker assigns one)
• :version - :v5 (default) or :v311
• :clean_start (true), :keep_alive_secs (30)
• :username, :password (binary)
• :will - %{topic: ..., payload: ..., qos: 0..2, retain: false}
• :connect_timeout_secs (10), :operation_timeout_secs (0: the default)
• :auto_reconnect (false), :reconnect_backoff_secs, :reconnect_max_backoff_secs
• :tls - %{ca_cert_pem: ..., client_cert_pem: ..., client_key_pem: ..., insecure_skip_certificate_verification: false}; %{} uses the system roots
• :max_packet_size (0: the default)

Unknown options raise ArgumentError.

Errors

Operations return {:error, {kind, message}} with kind one of :malformed_packet, :protocol, :io, :connection_refused, :not_connected, :packet_too_large, :already_connected, :timeout, :session.