Kafkaesque is a transactional outbox built for PostgreSQL and, primarily, Kafka.

• Transactional safety for messages: if they were created, they will be eventually published. They're only created if the transaction commits
• Ordering: messages are published sequentially for topic/partition combinations
• Shutdown safety: has graceful shutdown and rescue for cases where it doesn't happen.
• Observability: all operations publish telemetry events
• Garbage collection: outbox table is periodically cleaned

Add :kafkaesque to the list of dependencies in mix.exs:

def deps do
  [
    {:kafkaesque, "~> 1.0-rc.0"}
  ]
end

Check the Getting started guide in Hexdocs.