Because **FastAPI** doesn't make any changes to a `Response` you return, you have to make sure its contents are ready for it.

For example, you cannot put a Pydantic model in a `JSONResponse` without first converting it to a `dict` with all the data types (like `datetime`, `UUID`, etc) converted to JSON-compatible types.

For those cases, you can use the `jsonable_encoder` to convert your data before passing it to a response:

import org.opensearch.transport.client.Client;

import com.ibm.icu.text.Transliterator;

/**
 * AnalyzerConverter is a class that implements the ReadingConverter interface.
 * It is responsible for converting text using specified language analyzers.
 * The class uses a Transliterator to convert between Hiragana and Katakana.
 *
 * <p>Constructor:
 * <ul>

    /**
     * Default constructor for InputSource.
     */
    public InputSource() {}

    /**
     * Creates a new InputSource from an API model InputSource.
     * This constructor is used for converting between the API model and the compat model.
     *
     * @param source the API model InputSource to convert from
     */
    public InputSource(org.apache.maven.api.model.InputSource source) {

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.io.Serializable;
import org.jspecify.annotations.Nullable;

/**
 * Utility class for converting between various ASCII case formats. Behavior is undefined for
 * non-ASCII input.
 *
 * @author Mike Bostock
 * @since 1.0
 */
@GwtCompatible
public enum CaseFormat {
  /**

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.io.Serializable;
import org.jspecify.annotations.Nullable;

/**
 * Utility class for converting between various ASCII case formats. Behavior is undefined for
 * non-ASCII input.
 *
 * @author Mike Bostock
 * @since 1.0
 */
@GwtCompatible
public enum CaseFormat {
  /**

 * This class provides methods for converting binary data to readable hex format.
 */

public class Hexdump {

    /**
     * Default constructor.
     */
    public Hexdump() {
        // Utility class - no instance variables to initialize
    }

    /**
     * Array of hexadecimal digit characters used for converting binary data to hex representation.
     */

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.suggest.converter;

import java.io.IOException;
import java.util.List;

/**
 * Interface for converting text into its reading form.
 */
public interface ReadingConverter {

    /**
     * Returns the maximum number of readings.
     *
     * @return the maximum number of readings, default is 10.
     */

 */
package jcifs.util;

import jcifs.Encodable;

/**
 * Interface for objects that can be encoded to byte arrays.
 * Provides standardized method for converting objects to their binary representation.
 *
 * @author mbechler
 */
public class ByteEncodable implements Encodable {

    private final byte[] bytes;
    private final int off;
    private final int len;

Taking data from:

* The path as parameters.
* Headers.
* Cookies.
* etc.

And by doing so, **FastAPI** is validating that data, converting it and generating documentation for your API automatically.

But there are situations where you might need to access the `Request` object directly.

## Details about the `Request` object { #details-about-the-request-object }

    ]
}
```

## Recap { #recap }

Declare headers with `Header`, using the same common pattern as `Query`, `Path` and `Cookie`.