Doc(
                """
                The default response class to be used.

                Read more in the
                [FastAPI docs for Custom Response - HTML, Stream, File, others](https://fastapi.tiangolo.com/advanced/custom-response/#default-response-class).

                **Example**

                ```python
                from fastapi import FastAPI

### Custom Generate Unique ID Function { #custom-generate-unique-id-function }

FastAPI uses a **unique ID** for each *path operation*, which is used for the **operation ID** and also for the names of any needed custom models, for requests or responses.

You can customize that function. It takes an `APIRoute` and outputs a string.

            type[APIRoute],
            Doc(
                """
                Custom route (*path operation*) class to be used by this router.

                Read more about it in the
                [FastAPI docs for Custom Request and APIRoute class](https://fastapi.tiangolo.com/how-to/custom-request-and-route/#custom-apiroute-class-in-a-router).
                """
            ),
        ] = APIRoute,

                                                 title="Floating point number" required="required"
                                                 data-validation="custom"
                                                 data-validation-regexp="(\+|\-)?\d+(\.\d+)?((e|E)(\+|\-)?\d+)?"
                                                 data-validation-help="number (Float)"/>

            }
        };

        assertEquals("Custom protocolType should be WEB", ProtocolType.WEB, customAnnotation.protocolType());
        assertEquals("Custom message should match", "Test message", customAnnotation.message());
        assertEquals("Custom groups should have one element", 1, customAnnotation.groups().length);
        assertEquals("Custom payload should have one element", 1, customAnnotation.payload().length);

    private String id;
    /** The CSS class name to match */
    private String css;
    /** The custom attribute name to match */
    private String attrName;
    /** The custom attribute value to match */
    private String attrValue;

    /**
     * Creates a new PrunedTag instance with the specified tag name.
     *
     * @param tag the HTML tag name to match (e.g., "div", "span", "p")
     */

- **Features**: JavaScript rendering, authentication, custom headers

**File Crawling**:
- **Admin Path**: Crawler > File
- **Supports**: SMB, FTP, local file systems
- **Features**: Access control, file type filtering

**Data Store Crawling**:
- **Admin Path**: Crawler > Data Store
- **Supports**: Databases (via JDBC), CSV files, custom plugins
- **Features**: Incremental updates, custom field mapping

---

   * OkHttp in the current runtime. Use this to include the OkHttp version in custom `User-Agent`
   * headers.
   *
   * Official OkHttp releases follow [semantic versioning][semver]. Versions with the `-SNAPSHOT`
   * qualifier are not unique and should only be used in development environments. If you create
   * custom builds of OkHttp please include a qualifier your version name, like "4.7.0-mycompany.3".

Nevertheless, we can declare the expected schema for the request body.

### Custom OpenAPI content type { #custom-openapi-content-type }

Using this same trick, you could use a Pydantic model to define the JSON Schema that is then included in the custom OpenAPI schema section for the *path operation*.

And you could do this even if the data type in the request is not JSON.

{* ../../docs_src/middleware/tutorial001_py310.py hl[8:9,11,14] *}

/// tip

Keep in mind that custom proprietary headers can be added [using the `X-` prefix](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers).