# Header Parameters

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

## Import `Header`

First import `Header`:

//// tab | Python 3.10+

```Python hl_lines="3"
{!> ../../docs_src/header_params/tutorial001_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="3"
{!> ../../docs_src/header_params/tutorial001_an_py39.py!}
```

////

        router_sig = inspect.signature(router_method)
        app_sig = inspect.signature(app_method)
        param: inspect.Parameter
        for key, param in base_sig.parameters.items():
            router_param: inspect.Parameter = router_sig.parameters[key]
            app_param: inspect.Parameter = app_sig.parameters[key]
            assert param.annotation == router_param.annotation
            assert param.annotation == app_param.annotation

# Path Parameters and Numeric Validations

In the same way that you can declare more validations and metadata for query parameters with `Query`, you can declare the same type of validations and metadata for path parameters with `Path`.

## Import Path

First, import `Path` from `fastapi`, and import `Annotated`:

//// tab | Python 3.10+

```Python hl_lines="1  3"
{!> ../../docs_src/path_params_numeric_validations/tutorial001_an_py310.py!}
```

   * parameters.
   */
  public MediaType withoutParameters() {
    return parameters.isEmpty() ? this : create(type, subtype);
  }

  /**
   * Replaces all parameters with the given parameters.
   *
   * @throws IllegalArgumentException if any parameter or value is invalid
   */

    ImmutableList<Parameter> parameters = delegate.getParameters();
    assertEquals(2, parameters.size());
    assertEquals(String.class, parameters.get(0).getType().getType());
    assertTrue(parameters.get(0).isAnnotationPresent(NotBlank.class));
    assertEquals(int.class, parameters.get(1).getType().getType());
    assertFalse(parameters.get(1).isAnnotationPresent(NotBlank.class));
    new EqualsTester()

    ImmutableList<Parameter> parameters = delegate.getParameters();
    assertEquals(2, parameters.size());
    assertEquals(String.class, parameters.get(0).getType().getType());
    assertTrue(parameters.get(0).isAnnotationPresent(NotBlank.class));
    assertEquals(int.class, parameters.get(1).getType().getType());
    assertFalse(parameters.get(1).isAnnotationPresent(NotBlank.class));
    new EqualsTester()

  /** True if the agreed upon extension parameters includes "client_no_context_takeover". */
  @JvmField val clientNoContextTakeover: Boolean = false,
  /** Should be a value in [8..15]. Any value in that range is acceptable by OkHttp. */
  @JvmField val serverMaxWindowBits: Int? = null,
  /** True if the agreed upon extension parameters includes "server_no_context_takeover". */

///

/// tip

To declare File bodies, you need to use `File`, because otherwise the parameters would be interpreted as query parameters or body (JSON) parameters.

///

The files will be uploaded as "form data".

If you declare the type of your *path operation function* parameter as `bytes`, **FastAPI** will read the file for you and you will receive the contents as `bytes`.

    public void setParameters(List<Parameter> parameters) throws DuplicateParameterException {
        this.parameters.clear();
        for (Parameter parameter : parameters) {
            addParameter(parameter);
        }
    }

    /**
     * @param parameter add a new parameter
     * @throws DuplicateParameterException if any
     */
    public void addParameter(Parameter parameter) throws DuplicateParameterException {

        this.hostname = value;
    }

    public String getParameters() {
        checkSpecifiedProperty("parameters");
        return convertEmptyToNull(parameters);
    }

    public void setParameters(String value) {
        registerModifiedProperty("parameters");
        this.parameters = value;
    }

    public String getPassword() {
        checkSpecifiedProperty("password");