total: float


class InvoiceEvent(BaseModel):
    description: str
    paid: bool


class InvoiceEventReceived(BaseModel):
    ok: bool


invoices_callback_router = APIRouter()


@invoices_callback_router.post(
    "{$callback_url}/invoices/{$request.body.id}", response_model=InvoiceEventReceived
)
def invoice_notification(body: InvoiceEvent):
    pass

    total: float


class InvoiceEvent(BaseModel):
    description: str
    paid: bool


class InvoiceEventReceived(BaseModel):
    ok: bool


invoices_callback_router = APIRouter()


@invoices_callback_router.post(
    "{$callback_url}/invoices/{$request.body.id}", response_model=InvoiceEventReceived
)
def invoice_notification(body: InvoiceEvent):
    pass  # pragma: nocover


class Event(BaseModel):

                        "paid": {"title": "Paid", "type": "boolean"},
                    },
                },
                "InvoiceEventReceived": {
                    "title": "InvoiceEventReceived",
                    "required": ["ok"],
                    "type": "object",
                    "properties": {"ok": {"title": "Ok", "type": "boolean"}},
                },

{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

### 创建回调*路径操作*

创建回调*路径操作*也使用之前创建的 `APIRouter`。

它看起来和常规 FastAPI *路径操作*差不多：

* 声明要接收的请求体，例如，`body: InvoiceEvent`
* 还要声明要返回的响应，例如，`response_model=InvoiceEventReceived`

```Python hl_lines="17-19  22-23  29-33"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

回调*路径操作*与常规*路径操作*有两点主要区别：

* 它不需要任何实际的代码，因为应用不会调用这段代码。它只是用于存档*外部 API*。因此，函数的内容只需要 `pass` 就可以了

* It should probably have a declaration of the body it should receive, e.g. `body: InvoiceEvent`.
* And it could also have a declaration of the response it should return, e.g. `response_model=InvoiceEventReceived`.

```Python hl_lines="16-18  21-22  28-32"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

There are 2 main differences from a normal *path operation*:

* Sie sollte wahrscheinlich eine Deklaration des Bodys enthalten, die sie erhalten soll, z. B. `body: InvoiceEvent`.
* Und sie könnte auch eine Deklaration der Response enthalten, die zurückgegeben werden soll, z. B. `response_model=InvoiceEventReceived`.

```Python hl_lines="16-18  21-22  28-32"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

Es gibt zwei Hauptunterschiede zu einer normalen *Pfadoperation*:

```

### ✍ ⏲ *➡ 🛠️*

✍ ⏲ *➡ 🛠️* ⚙️ 🎏 `APIRouter` 👆 ✍ 🔛.

⚫️ 🔜 👀 💖 😐 FastAPI *➡ 🛠️*:

* ⚫️ 🔜 🎲 ✔️ 📄 💪 ⚫️ 🔜 📨, ✅ `body: InvoiceEvent`.
*  & ⚫️ 💪 ✔️ 📄 📨 ⚫️ 🔜 📨, ✅ `response_model=InvoiceEventReceived`.

```Python hl_lines="16-18  21-22  28-32"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

📤 2️⃣ 👑 🔺 ⚪️➡️ 😐 *➡ 🛠️*: