fix(vercel): keep a single ASGI entrypoint so the preset cannot build an uninstalled second function

Author: codebybilal18

Dockerfile

@@ -55,4 +55,4 @@ HEALTHCHECK --interval=30s --timeout=5s --start-period=40s --retries=3 \
 # Single worker by default: the process holds a database pool and, when the
 # local models are installed, model weights in memory. Scale with replicas, not
 # with workers.
-CMD ["sh", "-c", "uvicorn app.main:app --host 0.0.0.0 --port ${PORT} --workers 1 --timeout-keep-alive 75"]
+CMD ["sh", "-c", "uvicorn app.main:create_app --factory --host 0.0.0.0 --port ${PORT} --workers 1 --timeout-keep-alive 75"]

README.md

@@ -222,7 +222,7 @@ Without Docker:
 ```bash
 uv venv && uv pip install -r requirements.txt -r requirements-local.txt
 alembic upgrade head
-uvicorn app.main:app --reload
+uvicorn app.main:create_app --factory --reload
 ```
 
 > Already running Postgres on 5432? Set `POSTGRES_PORT=5433` in `.env` and update `DATABASE_URL`

app/main.py

@@ -88,4 +88,16 @@ async def unhandled(request: Request, exc: Exception) -> JSONResponse:
     return app
 
 
-app = create_app()
+# Deliberately no module-level `app = create_app()` here.
+#
+# Vercel's FastAPI preset scans the repo for a module-level ASGI instance and
+# builds whatever it finds as the function. With one in this module *and* one in
+# api/index.py it picked this file, while the dependency install was scoped to
+# the entrypoint declared in vercel.json — so the deployed function ran without
+# fastapi installed and died with ModuleNotFoundError at cold start.
+#
+# There is now exactly one ASGI callable in the repo, at api/index.py. Anything
+# that needs an instance builds one from the factory:
+#
+#     uvicorn app.main:create_app --factory
+

docker-compose.yml

@@ -56,7 +56,7 @@ services:
       - hf_cache:/home/documind/.cache/huggingface
     command: >
       sh -c "alembic upgrade head &&
-             uvicorn app.main:app --host 0.0.0.0 --port 8000 --reload"
+             uvicorn app.main:create_app --factory --host 0.0.0.0 --port 8000 --reload"
 
   # Optional second vector store, for the pgvector/Qdrant comparison.
   #   docker compose --profile qdrant up