Welcome to the Reception Center

In the Town Square, every helper stands behind a polished counter. When you ask a question, they tuck the answer into a tidy JSON box — labels on the outside, treasures inside — so your app can unwrap it without confusion.

• ✦Return a Python dict and FastAPI gift-wraps it as JSON.
• ✦Use response_model to promise the exact shape of the box.
• ✦Status codes are little colored stickers on the lid.

@app.get("/citizen/{id}")
def greet(id: int):
    return {"id": id, "hi": "🌟"}

Down Postbox Lane, citizens slip detailed letters through the slot. Pydantic, the kind postmaster, reads every line — checking names, ages, and shapes — before letting the letter into the city.

• ✦Define a BaseModel for every incoming letter.
• ✦Wrong types get a polite 422 reply, not a crash.
• ✦Nested models are letters tucked inside envelopes.

class Wish(BaseModel):
    text: str
    sparkles: int = 3

@app.post("/wish")
def make(w: Wish): return w

In the Lantern Garden, helpers don't stand in line. While one waits for a slow cloud to answer, the others keep lighting lanterns. Everyone's request glows in turn — quickly, gently, together.

• ✦async def lets a helper pause without blocking others.
• ✦await is a polite 'I'll wait here, you go ahead'.
• ✦Great for calling AI APIs, databases, and the weather.

@app.get("/weather")
async def sky():
    data = await ask_cloud()
    return data

At the top of Whisper Tower, two friends share a long brass tube. Once it's open, every giggle and idea travels instantly — no knocking, no goodbyes — until someone gently closes the lid.

• ✦WebSockets stay connected for live chats and games.
• ✦Send and receive whenever — both sides can speak.
• ✦Perfect for streaming AI replies token by token.

@app.websocket("/chat")
async def chat(ws: WebSocket):
    await ws.accept()
    await ws.send_text("hi ✨")