You can define Header parameters the same way you define `Query`, `Path` and `Cookie` parameters.

## Import `Header` { #import-header }

First import `Header`:

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[3] *}

## Declare `Header` parameters { #declare-header-parameters }

Then declare the header parameters using the same structure as with `Path`, `Query` and `Cookie`.

from OkHttp 4.x:

**OkHttp is now packaged as separate JVM and Android artifacts.** This allows us to offer
platform-specific features and optimizations. If your build system handles [Gradle module metadata],
this change should be automatic.

**MockWebServer has a new coordinate and package name.** We didn’t like that our old artifact

//
//msgp:tuple VolInfo
type VolInfo struct {
	// Name of the volume.
	Name string

	// Date and time when the volume was created.
	Created time.Time

	// total VolInfo counts
	count int

	// Date and time when the volume was deleted, if Deleted
	Deleted time.Time
}

// FilesInfo represent a list of files, additionally
// indicates if the list is last.

     * Note: this method is called twice from {@link #doInvoke(LookupContext)} and modifies context. First invocation
     * when {@link LookupContext#pushedUserProperties} is null will push user properties IF key does not already
     * exist among Java System Properties, and collects all they key it pushes. Second invocation happens AFTER
     * {@link PropertyContributor} SPI invocation, and "refreshes" already pushed user properties by re-writing them

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

 * for text analysis and search processing. This class is used in character mapping dictionaries to transform
 * text during indexing and search operations.
 *
 * <p>Each mapping item consists of one or more input character sequences that are mapped to a single output
 * character sequence. The mapping supports both original values and new values for update operations.</p>
 */

@app.get("/model-optional-alias-and-validation-alias")
def read_model_optional_alias_and_validation_alias(
    p: Annotated[HeaderModelOptionalAliasAndValidationAlias, Header()],
):
    return {"p": p.p}


@pytest.mark.parametrize(
    "path",
    [
        "/optional-alias-and-validation-alias",
        "/model-optional-alias-and-validation-alias",
    ],
)

/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */

package org.elasticsearch.gradle.internal.test.rest.transform.match;

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

This notification target supports two formats: _namespace_ and _access_.