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

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

So, with that type declaration, **FastAPI** gives you automatic request <abbr title="converting the string that comes from an HTTP request into Python data">"parsing"</abbr>.

///

## Data validation { #data-validation }

But if you go to the browser at <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, you will see a nice HTTP error of:

```JSON
{

client = TestClient(app)


def test_get_validation_error():
    response = client.get("/items/foo")
    assert response.status_code == 400, response.text
    assert "Validation errors:" in response.text
    assert "Field: ('path', 'item_id')" in response.text


def test_get_http_error():
    response = client.get("/items/3")
    assert response.status_code == 418, response.text

You can override these exception handlers with your own.

### Override request validation exceptions { #override-request-validation-exceptions }

When a request contains invalid data, **FastAPI** internally raises a `RequestValidationError`.

And it also includes a default exception handler for it.

  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.apache.maven.validation</groupId>
    <artifactId>parent</artifactId>
    <version>1</version>
  </parent>

  <groupId>org.apache.maven.validation</groupId>
  <artifactId>project</artifactId>
  <version>1.0.0-SNAPSHOT</version>

  <properties>
    <x>just/some/path</x>
  </properties>

    private enum ValidationReportLevel {
        NONE, // mute validation completely (validation issue collection still happens, it is just not reported!)
        INLINE, // inline, each "internal" problem one line next to mojo invocation
        SUMMARY, // at end, list of plugin GAVs along with ANY validation issues
        BRIEF, // each "internal" problem one line next to mojo invocation

    boolean isResolveDependencies();

    /**
     * Controls the level of validation to perform on processed models. By default, models are validated in strict mode.
     *
     * @param validationLevel The level of validation to perform on processed models, e.g.
     *            {@link org.apache.maven.model.building.ModelBuildingRequest#VALIDATION_LEVEL_STRICT}.

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.project.validation;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 */
@Deprecated
public class ModelValidationResult {

    /** */

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