Todo App — Atelier Event Integration Demo

A simple todo app that emits events to Atelier on every operation. Use it to see how external apps trigger agent workflows via Atelier's event system.

Events Emitted

Event	When	Payload
todo.created	A new todo is added	{id, title, description, priority, completed, created_at}
todo.updated	A todo is edited	{...todo, changes: {fields that changed}}
todo.completed	A todo is marked done	{id, title, description, priority, completed, created_at}
todo.deleted	A todo is removed	{id, title, description, priority, completed, created_at}

Setup

# 1. Install dependencies
uv sync

# 2. Configure Atelier connection
cp .env.example .env
# Edit .env with your Atelier URL and API key

# 3. Run
≈

Open http://127.0.0.1:3001

Environment Variables

Variable	Description	Default
ATELIER_URL	Atelier backend URL	(empty — events skipped)
ATELIER_API_KEY	Your per-user API key from Atelier Config page	(empty — events skipped)

How It Works

1. Todo app — a FastAPI app with an in-memory store and a single-file HTML frontend. CRUD operations on todos.
2. Event integration (integration.py) — a thin emit_event() helper that POSTs to Atelier's /api/v1/events endpoint with an event type and payload. Fire-and-forget: if Atelier is unreachable, the todo operation still succeeds.
3. Atelier side — in the Atelier UI, create a workflow that subscribes to todo.* (or a specific event like todo.completed). When the todo app emits a matching event, Atelier queues a run and your agent processes it.

Example Workflow

In Atelier, create a workflow:

• Event type: todo.completed
• Agent: your agent
• Instructions: "When a todo is completed, send a congratulations notification to the user."

Now when you check off a todo in this app, Atelier's agent runs automatically.

MCP Tools

The same server exposes todo operations as MCP tools at http://127.0.0.1:3001/mcp.

In Atelier, add an MCP connection:

• URL: http://127.0.0.1:3001/mcp
• Transport: Streamable HTTP

Available tools: list_todos, get_todo, create_todo, update_todo, toggle_todo, delete_todo.

This lets your Atelier agents manage todos directly — e.g., a workflow triggered by todo.completed can call list_todos to check if all are done, then create_todo to add a new one.

Project Structure

todo-app/
  main.py           # FastAPI app + HTML frontend + MCP mount
  mcp_tools.py      # MCP tool definitions
  integration.py    # Atelier event emitter
  pyproject.toml    # Dependencies
  .env.example      # Environment template

API Endpoints

Method	Path	Description
GET	/	HTML frontend
GET	/api/todos	List all todos
POST	/api/todos	Create a todo
PATCH	/api/todos/{id}	Update a todo
DELETE	/api/todos/{id}	Delete a todo
POST	/api/todos/{id}/toggle	Toggle completed