},
            {
                "name": "Bar",
                "price": "35.4",
            },
            {
                "name": "Baz",
                "price": "thirty five point four",
            },
        ],
    ),
):
    results = {"item_id": item_id, "item": item}

                "invalid": {
                    "summary": "Invalid data is rejected with an error",
                    "value": {
                        "name": "Baz",
                        "price": "thirty five point four",
                    },
                },
            },
        ),
    ],
):
    results = {"item_id": item_id, "item": item}

                "invalid": {
                    "summary": "Invalid data is rejected with an error",
                    "value": {
                        "name": "Baz",
                        "price": "thirty five point four",
                    },
                },
            },
        ),
    ],
):
    results = {"item_id": item_id, "item": item}

!!! tip
    When writing the code to document a callback, it might be useful to imagine that you are that *external developer*. And that you are currently implementing the *external API*, not *your API*.

    Temporarily adopting this point of view (of the *external developer*) can help you feel like it's more obvious where to put the parameters, the Pydantic model for the body, for the response, etc. for that *external API*.

### Create a callback `APIRouter`

# Full Stack FastAPI Template

Templates, while typically come with a specific setup, are designed to be flexible and customizable. This allows you to modify and adapt them to your project's requirements, making them an excellent starting point. 🏁

You can use this template to get started, as it includes a lot of the initial set up, security, database and some API endpoints already done for you.

                                            {
                                                "name": "Baz",
                                                "price": "thirty five point four",
                                            },
                                        ],
                                    }
                                )
                                | IsDict(

                                            {
                                                "name": "Baz",
                                                "price": "thirty five point four",
                                            },
                                        ],
                                    }
                                )
                                | IsDict(

            },
            "invalid": {
                "summary": "Invalid data is rejected with an error",
                "value": {
                    "name": "Baz",
                    "price": "thirty five point four",
                },
            },
        },
    ),
):
    results = {"item_id": item_id, "item": item}

                                            {
                                                "name": "Baz",
                                                "price": "thirty five point four",
                                            },
                                        ],
                                    }
                                )
                                | IsDict(

                                            {
                                                "name": "Baz",
                                                "price": "thirty five point four",
                                            },
                                        ],
                                    }
                                )
                                | IsDict(