This is a work in progress Slack Real Time Messaging API client for Elixir. You'll need a Slack API token which can be retrieved from the Web API page or by creating a new bot integration.

Add Slack to your mix.exs application and dependencies methods. You'll also need websocket_client since hex.pm doesn't install git based dependencies.

def application do
  [applications: [:logger, :slack]]
end

def deps do
  [{:slack, "~> 0.3.0"},
   {:websocket_client, git: "https://github.com/jeremyong/websocket_client"}]
end

Define a module that uses the Slack behaviour and defines the appropriate callback methods.

defmodule SlackRtm do
  use Slack

  def init(initial_state, slack) do
    IO.puts "Connected as #{slack.me.name}"
    {:ok, initial_state}
  end

  def handle_message(message = %{type: "message"}, slack, state) do
    message_to_send = "Received #{length(state)} messages so far!"
    send_message(message_to_send, message.channel, slack)

    {:ok, state ++ [message.text]}
  end

  def handle_message(_message, _slack, state) do
    {:ok, state}
  end
end

To run this example, you'll also want to call SlackRtm.start_link("token", []) and run the project with mix run --no-halt.

You can send messages to channels using send_message/3 which takes the message as the first argument, channel as the second, and the passed in slack state as the third.

The passed in slack state holds the current user properties as me, team properties as team, the current websocket connection as socket, and a list of bots, channels, groups, and users.

Slack has a lot of message types so it's a good idea to define a callback like above where unhandled message types don't crash your application. You can find a list of message types and examples on the RTM API page.

You can find more detailed documentation on the Slack hexdocs page.