Sending a body with a `GET` request has an undefined behavior in the specifications, nevertheless, it is supported by FastAPI, only for very complex/extreme use cases.

    As it is discouraged, the interactive docs with Swagger UI won't show the documentation for the body when using `GET`, and proxies in the middle might not support it.

## Import Pydantic's `BaseModel`

First, you need to import `BaseModel` from `pydantic`:

=== "Python 3.10+"

            Doc(
                """
                List of *path operations* that will be used as OpenAPI callbacks.

                This is only for OpenAPI documentation, the callbacks won't be used
                directly.

                It will be added to the generated OpenAPI (e.g. visible at `/docs`).

                Read more about it in the

    return burgers
```

使用 `async def`，Python 就知道在该函数中，它将遇上 `await`，并且它可以"暂停" ⏸ 执行该函数，直至执行其他操作 🔀 后回来。

当你想调用一个 `async def` 函数时，你必须"等待"它。因此，这不会起作用：

```Python
# This won't work, because get_burgers was defined with: async def
burgers = get_burgers(2)
```

---

因此，如果您使用的库告诉您可以使用 `await` 调用它，则需要使用 `async def` 创建路径操作函数 ，如：

```Python hl_lines="2-3"
@app.get('/burgers')