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Todo CLI Application ​

The example/todo application is a fully functional, production-ready CQRS application.

It features an HTTP server powered by flux, and an interactive terminal UI (TUI) client built with Bubble Tea.

What it demonstrates ​

This application is designed to teach you how to build a real-world system using the standard flux project layout.

  1. Strict CQRS: The Write models (Aggregates) and Read models (Projections) are completely separated.
  2. HTTP API: How to expose the flux.CommandBus and flux.QueryBus over REST endpoints.
  3. Real-Time Projections: How to listen to the flux.EventBus and update an SQLite or in-memory Read Model.
  4. Server-Sent Events (SSE): How the server broadcasts Domain Events in real-time to connected clients.
  5. Interactive UI: A beautiful terminal client that reacts instantly to state changes.

Running the Example ​

This example requires you to run both a server and a client.

1. Start the Server:

bash
cd example/todo
go run ./cmd/server

2. Start the Interactive CLI Client: Open a new terminal window:

bash
cd example/todo
go run ./cmd/todo

Source Code Highlights ​

Take a deep dive into the example/todo/internal/todo package to see the architecture in action:

  • aggregates/: Look at list.go to see how Todo lists manage their own state and emit TaskAdded or TaskCompleted events.
  • projections/: Look at stats/projector.go to see how the system builds a blazing-fast global Read Model (tracking total active vs archived tasks) by listening to events across all lists!
  • api/: See how HTTP routes are bound directly to the commandBus and queryBus.