Complex Workflows in Elixir with Reactor (+ AI Agents)

Reactor is an Elixir library for orchestrating complex workflows with automatic rollbacks, sagas, and concurrent execution.

In this video, we build a travel booking system that coordinates flights, hotels, and emails—then turn it into an AI agent using Ash AI.

Reactor handles the complexity of distributed transactions across multiple services, automatically undoing operations when something fails downstream. Perfect for payment gateways, reservation systems, or any multi-step process that needs reliability.

We'll cover:

- Dependency graphs and concurrent step execution

- Implementing sagas with compensating actions

- Retries and error handling strategies

- Integration with Ash Framework

- Building an AI travel agent with function calling

Links:

Screen recording software I use (affiliate): https://screen.studio/@Yy75o

Reactor Livebook: https://gist.github.com/ChristianAlexander/a83a7189c1509939ac3b7b8812b1b0f2

Project Repo: https://github.com/ChristianAlexander/travel_agency

Reactor docs: https://hexdocs.pm/reactor/readme.html

Reactor cheat sheet: https://hexdocs.pm/reactor/reactor-cheatsheet.html

Ash AI: https://github.com/ash-project/ash_ai

Timestamps:

What's Reactor? - 00:00

Livebook Reactor Demo - 01:31

The AI Part - 07:19