store: Fix: Replace manual db.close() calls with FastAPI middleware in paper-dynasty-database

graph/fixes/fix-replace-manual-dbclose-calls-with-fastapi-middleware-in-8a4ae0.md

@@ -0,0 +1,44 @@
+---
+id: 8a4ae0ed-5bac-459b-bdd8-d3075bfc108d
+type: fix
+title: "Fix: Replace manual db.close() calls with FastAPI middleware in paper-dynasty-database"
+tags: [paper-dynasty-database, fastapi, peewee, python, middleware, database, connection-management]
+importance: 0.7
+confidence: 0.8
+created: "2026-03-03T05:38:10.354619+00:00"
+updated: "2026-03-03T05:38:10.354619+00:00"
+---
+
+## Problem
+467 manual `db.close()` calls across 30 router files in `app/routers_v2/`. Any uncaught exception would leak a Peewee DB connection. Brittle to maintain.
+
+## Solution
+Added `db_session_middleware` to `app/main.py` using FastAPI's `@app.middleware("http")` decorator:
+
+```python
+@app.middleware("http")
+async def db_session_middleware(request: Request, call_next):
+    try:
+        db.connect(reuse_if_open=True)
+        response = await call_next(request)
+        return response
+    finally:
+        if not db.is_closed():
+            db.close()
+```
+
+Used `db.connect(reuse_if_open=True)` — safe for both SQLite and `PooledPostgresqlDatabase` (pool returns connection on close).
+
+Removed all `db.close()` lines from routers with a Python regex script:
+```python
+re.sub(r'^[ \t]*db\.close\(\)\n', '', content, flags=re.MULTILINE)
+```
+
+## Files Changed
+- `app/main.py` — added import + middleware (11 lines)
+- `app/routers_v2/*.py` — removed db.close() from 30 files
+
+## Notes
+- `db.close()` at end of `db_engine.py` (line 1067) is initialization cleanup — intentionally kept
+- Some router files now have unused `db` imports (only used for db.close()) — harmless, can clean up later
+- PR #33 in paper-dynasty-database