Skip to content

fastapi_layer.md

Latest commit

 

History

History
127 lines (86 loc) · 3.77 KB

fastapi_layer.md

File metadata and controls

127 lines (86 loc) · 3.77 KB

GatorChef Backend — FastAPI + Uvicorn Layer

Stack

Layer Role
Uvicorn (uvicorn==0.35.0) ASGI server. Listens on port 8000, hands requests to FastAPI.
FastAPI Routing, Pydantic validation, dependency injection, auto-docs.

No Django, no Flask, no Express.

QUESTIONS

Was it already there?

Yes — uvicorn==0.35.0 was in requirements.txt from commit one. Our changes added httpx, glmocr, and python-multipart alongside it, but uvicorn was always the server.

Is it for the model?

No — uvicorn has nothing to do with GLM-OCR. The relationship is: Uvicorn → serves your FastAPI app → FastAPI routes call glm_ocr_service (web server) (your backend code) (which calls Zhipu's cloud)

Starting the Server

cd server
pip install -r requirements.txt        # first time only
uvicorn app.main:app --reload --port 8000
# or, if uvicorn isn't in PATH:
python -m uvicorn app.main:app --reload --port 8000

--reload auto-restarts on file changes. Remove it in production.

Request Flow

React (port 5173)
  └─ HTTP + Authorization: Bearer <Firebase token>
       └─ Uvicorn (port 8000)
            └─ FastAPI matches route
                 └─ Depends(get_current_user) validates token
                      └─ Route handler runs
                           └─ Pydantic validates body / response
                                └─ JSON → frontend

Entry Point

server/app/main.py — creates the FastAPI app, registers CORS middleware, and mounts all routers:

app = FastAPI(title="GatorChef Backend")
app.add_middleware(CORSMiddleware, allow_origins=[...])  # localhost:5173, localhost:8080
app.include_router(pantry_router)
app.include_router(ingredients_router)
app.include_router(upload_router)
app.include_router(users_router)

A single GET /health route lives here for uptime checks.

Routers (server/app/routes/)

Each file declares router = APIRouter(prefix="...", tags=["..."]) and is registered in main.py.

File Prefix Responsibility
pantry.py /pantry CRUD for pantry items
ingredients.py /ingredients Canonical ingredient list (TheMealDB)
upload.py /upload POST receipt image → GLM-OCR → pantry
users.py /users User profile management

Auth

Protected routes use FastAPI's dependency injection:

current_user: AuthenticatedUser = Depends(get_current_user)

get_current_user (server/app/dependencies/auth.py) validates the Firebase ID token from the Authorization: Bearer <token> header and returns AuthenticatedUser(uid, email).

GET /ingredients is the only unprotected route.

Pydantic Schemas (server/app/schemas/)

FastAPI validates requests and responses automatically. Invalid input returns a 422 with field-level error detail.

Schema Used for
PantryItemCreate POST /pantry request body
PantryItemUpdate PUT /pantry/{id} request body
PantryItemResponse All pantry endpoint responses (includes id)

Service Layer (server/app/services/)

Routes contain no business logic — they delegate to services:

Route Service(s)
pantry.py pantry_service.py (Firestore)
upload.py glm_ocr_service.py → ingredient_loader.py
ingredients.py ingredient_loader.py

Services are module-level singletons (pantry_service = PantryService()) or plain async functions.

Auto-generated API Docs

FastAPI builds interactive docs from the code — no maintenance required:

  • Swagger UI: http://localhost:8000/docs
  • ReDoc: http://localhost:8000/redoc

Use these to test endpoints directly in the browser instead of writing curl commands.