This schema definition includes your API paths, the possible parameters they take, etc.

#### Data "schema" { #data-schema }

The term "schema" might also refer to the shape of some data, like a JSON content.

In that case, it would mean the JSON attributes, and data types they have, etc.

#### OpenAPI and JSON Schema { #openapi-and-json-schema }

{* ../../docs_src/extending_openapi/tutorial001_py310.py hl[1,4,7:9] *}

### 生成 OpenAPI 架构 { #generate-the-openapi-schema }

然后，在一个 `custom_openapi()` 函数中使用同一个工具函数生成 OpenAPI 架构：

{* ../../docs_src/extending_openapi/tutorial001_py310.py hl[2,15:21] *}

### 修改 OpenAPI 架构 { #modify-the-openapi-schema }

现在你可以添加 ReDoc 扩展，在 OpenAPI 架构的 `info` “对象”中加入自定义 `x-logo`：

**FastAPI** will take the Pydantic model from there, generate the JSON Schema, and put it in the correct place.

The correct place is:

* In the key `content`, that has as value another JSON object (`dict`) that contains:
    * A key with the media type, e.g. `application/json`, that contains as value another JSON object, that contains:
        * A key `schema`, that has as the value the JSON Schema from the model, here's the correct place.

	keys := make([]string, 0, len(mapValue))
	for k := range mapValue {
		keys = append(keys, k)
	}
	sort.Strings(keys)

	for _, k := range keys {
		value := mapValue[k]
		if stmt.Schema != nil {
			if field := stmt.Schema.LookUpField(k); field != nil {
				k = field.DBName
			}
		}

		if v, ok := selectColumns[k]; (ok && v) || (!ok && !restricted) {
			values.Columns = append(values.Columns, clause.Column{Name: k})

)
def test_optional_str_schema(path: str):
    assert app.openapi()["paths"][path]["get"]["parameters"] == snapshot(
        [
            {
                "required": False,
                "schema": {
                    "anyOf": [{"type": "string"}, {"type": "null"}],
                    "title": "P",
                },
                "name": "p",
                "in": "header",
            }
        ]

### OpenAPI { #openapi }

**FastAPI** generiert ein „Schema“ mit all Ihren APIs unter Verwendung des **OpenAPI**-Standards zur Definition von APIs.

#### „Schema“ { #schema }

Ein „Schema“ ist eine Definition oder Beschreibung von etwas. Nicht der eigentliche Code, der es implementiert, sondern lediglich eine abstrakte Beschreibung.

#### API-„Schema“ { #api-schema }

                                "content": {"application/json": {"schema": {}}},
                            },
                            "422": {
                                "description": "Validation Error",
                                "content": {
                                    "application/json": {
                                        "schema": {

                    # this is how one would imagine the openapi schema to be
                    # but since the key is not valid, openapi.utils.get_openapi will raise ValueError
                    "hello": {"description": "Not a valid additional response"},
                    "200": {
                        "description": "Successful Response",
                        "content": {"application/json": {"schema": {}}},
                    },
                },

#### «Схема» даних { #data-schema }

Термін «схема» також може відноситися до форми деяких даних, наприклад, вмісту JSON.

У цьому випадку це означає атрибути JSON і типи даних, які вони мають, тощо.

#### OpenAPI і JSON Schema { #openapi-and-json-schema }

///

{* ../../docs_src/separate_openapi_schemas/tutorial002_py310.py hl[10] *}

### Same Schema for Input and Output Models in Docs { #same-schema-for-input-and-output-models-in-docs }

And now there will be one single schema for input and output for the model, only `Item`, and it will have `description` as **not required**:

<div class="screenshot">