feat(sse): sync temps réel multi-appareils via Server-Sent Events v0.5.8

- Broadcaster asyncio.Queue avec keepalive 25s (prévient timeout proxy)
- Endpoint GET /api/events/stream (StreamingResponse text/event-stream)
- Broadcast notes_changed / todos_changed / shopping_changed sur toutes mutations
- Hook useServerEvents: EventSource avec reconnexion automatique (3s)
- Pages Notes, Todos, Shopping abonnées aux événements SSE
- nginx: location SSE dédiée (proxy_buffering off, timeout 24h)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/api/events.py

@@ -0,0 +1,18 @@
+from fastapi import APIRouter
+from fastapi.responses import StreamingResponse
+
+from app.core.broadcaster import broadcaster
+
+router = APIRouter()
+
+
+@router.get("/stream")
+async def event_stream():
+    return StreamingResponse(
+        broadcaster.subscribe(),
+        media_type="text/event-stream",
+        headers={
+            "Cache-Control": "no-cache",
+            "X-Accel-Buffering": "no",
+        },
+    )

backend/app/api/notes.py

@@ -5,6 +5,7 @@ from sqlalchemy import select, text, and_
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import selectinload
 
+from app.core.broadcaster import broadcaster
 from app.core.database import get_session
 from app.core.redis import enqueue
 from app.models.notes import NoteItem, NoteAttachment
@@ -74,6 +75,7 @@ async def create_note(payload: NoteCreate, session: AsyncSession = Depends(get_s
     await session.commit()
     await session.refresh(note, ["attachments"])
     await enqueue("export_note_markdown", str(note.id))
+    broadcaster.broadcast("notes_changed")
     return note
 
 
@@ -97,6 +99,7 @@ async def update_note(
     await session.commit()
     await session.refresh(note, ["attachments"])
     await enqueue("export_note_markdown", str(note.id))
+    broadcaster.broadcast("notes_changed")
     return note
 
 
@@ -108,6 +111,7 @@ async def delete_note(note_id: uuid.UUID, session: AsyncSession = Depends(get_se
     await session.delete(note)
     await session.commit()
     await enqueue("remove_note_markdown", str(note_id))
+    broadcaster.broadcast("notes_changed")
     return Response(status_code=204)
 
 
@@ -151,6 +155,7 @@ async def add_attachment(
     await session.commit()
     await session.refresh(note, ["attachments"])
     await enqueue("export_note_markdown", str(note_id))
+    broadcaster.broadcast("notes_changed")
     return note
 
 
@@ -177,4 +182,5 @@ async def delete_attachment(
     await session.delete(att)
     await session.commit()
     await enqueue("export_note_markdown", str(note_id))
+    broadcaster.broadcast("notes_changed")
     return Response(status_code=204)

backend/app/api/shopping.py

@@ -1,4 +1,3 @@
-# backend/app/api/shopping.py
 import uuid
 from datetime import datetime, timezone, date as date_type
 from decimal import Decimal
@@ -8,6 +7,8 @@ from sqlalchemy import select, text, or_
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import selectinload
 
+from app.core.broadcaster import broadcaster
+
 from app.core.database import get_session
 from app.models.shopping import ShoppingList, ListItem, Product, Store
 from app.schemas.shopping import (
@@ -172,6 +173,7 @@ async def create_shopping_list(
     session.add(lst)
     await session.commit()
     await session.refresh(lst, ["items"])
+    broadcaster.broadcast("shopping_changed")
     return ShoppingListDetailResponse(
         **_list_to_response(lst).model_dump(),
         items=[],
@@ -214,6 +216,7 @@ async def update_shopping_list(
     for field, value in payload.model_dump(exclude_unset=True).items():
         setattr(lst, field, value)
     await session.commit()
+    broadcaster.broadcast("shopping_changed")
     sorted_items = sorted(lst.items, key=lambda i: (i.sort_order or 999, str(i.id)))
     return ShoppingListDetailResponse(
         **_list_to_response(lst).model_dump(),
@@ -228,6 +231,7 @@ async def delete_shopping_list(list_id: uuid.UUID, session: AsyncSession = Depen
         raise HTTPException(404, "Liste introuvable")
     await session.delete(lst)
     await session.commit()
+    broadcaster.broadcast("shopping_changed")
     return Response(status_code=204)
 
 
@@ -245,6 +249,7 @@ async def add_item(
     item = ListItem(list_id=list_id, **payload.model_dump())
     session.add(item)
     await session.commit()
+    broadcaster.broadcast("shopping_changed")
     stmt = (
         select(ListItem)
         .where(ListItem.id == item.id)
@@ -294,6 +299,7 @@ async def update_item(
             product.frequency_score += 1
 
     await session.commit()
+    broadcaster.broadcast("shopping_changed")
     await session.refresh(item, ["product"])
     return _item_to_response(item)
 
@@ -311,6 +317,7 @@ async def delete_item(
         raise HTTPException(404, "Article introuvable")
     await session.delete(item)
     await session.commit()
+    broadcaster.broadcast("shopping_changed")
     return Response(status_code=204)
 
 
@@ -386,6 +393,7 @@ async def generate_magic_list(session: AsyncSession = Depends(get_session)):
         ))
 
     await session.commit()
+    broadcaster.broadcast("shopping_changed")
 
     stmt = (
         select(ShoppingList)
@@ -433,6 +441,7 @@ async def finish_shopping(list_id: uuid.UUID, session: AsyncSession = Depends(ge
             ))
 
     await session.commit()
+    broadcaster.broadcast("shopping_changed")
     sorted_items = sorted(lst.items, key=lambda i: (i.sort_order or 999, str(i.id)))
     return ShoppingListDetailResponse(
         **_list_to_response(lst).model_dump(),

backend/app/api/todos.py

@@ -5,6 +5,7 @@ from fastapi.responses import Response
 from sqlalchemy import select, and_
 from sqlalchemy.ext.asyncio import AsyncSession
 
+from app.core.broadcaster import broadcaster
 from app.core.database import get_session
 from app.models.todos import TodoItem
 from app.schemas.todos import TodoCreate, TodoUpdate, PostponeRequest, TodoResponse
@@ -55,6 +56,7 @@ async def create_todo(
     session.add(item)
     await session.commit()
     await session.refresh(item)
+    broadcaster.broadcast("todos_changed")
     return item
 
 
@@ -74,6 +76,7 @@ async def update_todo(
 
     await session.commit()
     await session.refresh(item)
+    broadcaster.broadcast("todos_changed")
     return item
 
 
@@ -87,6 +90,7 @@ async def delete_todo(
         raise HTTPException(status_code=404, detail="Tâche introuvable")
     await session.delete(item)
     await session.commit()
+    broadcaster.broadcast("todos_changed")
     return Response(status_code=204)
 
 
@@ -108,4 +112,5 @@ async def postpone_todo(
 
     await session.commit()
     await session.refresh(item)
+    broadcaster.broadcast("todos_changed")
     return item

backend/app/core/broadcaster.py

@@ -0,0 +1,36 @@
+import asyncio
+import json
+from typing import AsyncGenerator
+
+
+class EventBroadcaster:
+    def __init__(self):
+        self._queues: set[asyncio.Queue] = set()
+
+    async def subscribe(self) -> AsyncGenerator[str, None]:
+        queue: asyncio.Queue[str] = asyncio.Queue(maxsize=32)
+        self._queues.add(queue)
+        try:
+            while True:
+                try:
+                    msg = await asyncio.wait_for(queue.get(), timeout=25)
+                    yield msg
+                except asyncio.TimeoutError:
+                    yield ": keepalive\n\n"
+        except asyncio.CancelledError:
+            pass
+        finally:
+            self._queues.discard(queue)
+
+    def broadcast(self, event_type: str, data: dict | None = None) -> None:
+        if not self._queues:
+            return
+        msg = f"event: {event_type}\ndata: {json.dumps(data or {})}\n\n"
+        for queue in list(self._queues):
+            try:
+                queue.put_nowait(msg)
+            except asyncio.QueueFull:
+                pass
+
+
+broadcaster = EventBroadcaster()

backend/app/main.py

@@ -4,6 +4,7 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.staticfiles import StaticFiles
 from app.api.admin import router as admin_router
+from app.api.events import router as events_router
 from app.api.health import router as health_router
 from app.api.media import router as media_router
 from app.api.notes import router as notes_router
@@ -36,6 +37,7 @@ app.add_middleware(
 )
 
 app.include_router(health_router, prefix="/api")
+app.include_router(events_router, prefix="/api/events")
 app.include_router(admin_router, prefix="/api/admin")
 app.include_router(media_router, prefix="/api/media")
 app.include_router(notes_router, prefix="/api/notes")