Behaviour and macro for building A2UI agents.

use A2UI.Agent eliminates GenServer boilerplate for agents that serve A2UI protocol messages to connected clients. Agents implement only the callbacks that matter: init/1, handle_connect/2, and handle_action/3.

Example

defmodule MyAgent do
  use A2UI.Agent

  def init(_opts), do: {:ok, %{}}

  @impl A2UI.Agent
  def handle_connect(conn, state) do
    A2UI.Agent.send_message(conn, %CreateSurface{surface_id: "main"})
    {:noreply, state}
  end

  @impl A2UI.Agent
  def handle_action(action, conn, state) do
    IO.inspect(action.name)
    {:noreply, state}
  end
end

Callbacks

Required:

• init/1 — receives keyword opts, returns {:ok, state} or {:stop, reason}
• handle_connect/2 — called when a client connects
• handle_action/3 — called when a user triggers an action

Optional (default no-op):

• handle_disconnect/2 — called when a client disconnects or its process dies
• handle_info/2 — called for any non-A2UI messages