Drinkup#

An Elixir library for listening to events from an ATProtocol relay (firehose/com.atproto.sync.subscribeRepos). Eventually aiming to support any ATProtocol subscription.

TODO#

• Support for different subscriptions other than `com.atproto.sync.subscribeRepo'.
• Validation (signatures, making sure to only track handle active accounts, etc.) (see Firehose Validation Best Practices)
• Look into backfilling? See if there's better ways to do it.
• Built-in solutions for tracking resumption? (probably a pluggable solution to allow for different things like Mnesia, Postgres, etc.)
• Testing of multi-node/distribution.
• Tests
• Documentation

Installation#

Add drinkup to your mix.exs.

def deps do
  [
    {:drinkup, "~> 0.1"}
  ]
end

Documentation can be found on HexDocs at https://hexdocs.pm/drinkup.

Example Usage#

First, create a module implementing the Drinkup.Consumer behaviour (only requires a handle_event/1 function):

defmodule ExampleConsumer do
  @behaviour Drinkup.Consumer

  def handle_event(%Drinkup.Event.Commit{} = event) do
    IO.inspect(event, label: "Got commit event")
  end

  def handle_event(_), do: :noop
end

Then add Drinkup and your consumer to your application's supervision tree:

defmodule MyApp.Application do
  use Application

  def start(_type, _args) do
    children = [{Drinkup, %{consumer: ExampleConsumer}}]
    Supervisor.start_link(children, strategy: :one_for_one)
  end
end

You should then be able to start your application and start seeing Got commit event: ... in the terminal.

Record Consumer#

One of the main reasons for listening to an ATProto relay is to synchronise a database with records. As a result, Drinkup provides a light extension around a basic consumer, the RecordConsumer, which only listens to commit events, and transforms them into a slightly nicer structure to work around, calling your handle_create/1, handle_update/1, and handle_delete/1 functions for each record it comes across. It also allows for filtering of specific types of records either by full name or with a Regex match.

defmodule ExampleRecordConsumer do
  # Will respond to any events either `app.bsky.feed.post` records, or anything under `app.bsky.graph`.
  use Drinkup.RecordConsumer, collections: [~r/app\.bsky\.graph\..+/, "app.bsky.feed.post"]
  alias Drinkup.RecordConsumer.Record

  def handle_create(%Record{type: "app.bsky.feed.post"} = record) do
    IO.inspect(record, label: "Bluesky post created")
  end

  def handle_create(%Record{type: "app.bsky.graph" <> _} = record) do
    IO.inspect(record, label: "Bluesky graph updated")
  end

  def handle_update(record) do
    # ...
  end

  def handle_delete(record) do
    # ...
  end
end

Special thanks#

The process structure used in Drinkup is heavily inspired by the work done on Nostrum, an incredible Elixir library for Discord.

License#

This project is licensed under the MIT License