"input": "foo"
    }
  ]
}
```

because the path parameter `item_id` had a value of `"foo"`, which is not an `int`.

The same error would appear if you provided a `float` instead of an `int`, as in: <a href="http://127.0.0.1:8000/items/4.2" class="external-link" target="_blank">http://127.0.0.1:8000/items/4.2</a>

/// check

So, with the same Python type declaration, **FastAPI** gives you data validation.

And Swagger UI has supported this particular `examples` field for a while. So, you can use it to **show** different **examples in the docs UI**.

The shape of this OpenAPI-specific field `examples` is a `dict` with **multiple examples** (instead of a `list`), each with extra information that will be added to **OpenAPI** too.

This doesn't go inside of each JSON Schema contained in OpenAPI, this goes outside, in the *path operation* directly.

* Designed around these standards, after a meticulous study. Instead of an afterthought layer on top.
* This also allows using automatic **client code generation** in many languages.

### Automatic docs { #automatic-docs }

# `container_path` to be a legitimate C:\ path, in this case, 'C:\drive_t',
# this symlink does allow for the convenience of passing unedited paths
# to `docker exec` commands, e.g., 'T:\path', instead of 'C:\path',
# without having to replace the drive letter with C:\ every time.
# Such a workaround is not required on Linux, since it
# can create arbitrary paths within the container, e.g., '/t'.

        try {
            /* TODO: Enhance the PluginDependenciesResolver to provide a
             * resolveCoreExtension method which uses a CoreExtension
             * object instead of a Plugin as this makes no sense.
             */
            Plugin plugin = Plugin.newBuilder()
                    .groupId(interpolator.apply(extension.getGroupId()))

 * In addition to usual getters using {@code getXxx} or {@code isXxx} suffixes, accessors
 * using {@code asXxx} or {@code toXxx} prefixes are also supported.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@Deprecated(since = "4.0.0")
public class ReflectionValueExtractor {
    private static final Object[] OBJECT_ARGS = new Object[0];

    /**

import org.apache.maven.model.merge.MavenModelMerger;
import org.codehaus.plexus.util.StringUtils;

/**
 * Handles inheritance of model values.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@SuppressWarnings({"checkstyle:methodname"})
@Named
@Singleton
@Deprecated(since = "4.0.0")
public class DefaultInheritanceAssembler implements InheritanceAssembler {

If you are building a <abbr title="Command Line Interface">CLI</abbr> app to be used in the terminal instead of a web API, check out <a href="https://typer.tiangolo.com/" class="external-link" target="_blank">**Typer**</a>.

**Typer** is FastAPI's little sibling. And it's intended to be the **FastAPI of CLIs**. ⌨️ 🚀

        assertViolations(result, 0, 0, 1);

        assertContains(
                result.getWarnings().get(0),
                "'dependencies.dependency.systemPath' for test:a:jar should use a variable instead of a hard-coded path");

        SimpleProblemCollector result31 =
                validateRaw("hard-coded-system-path.xml", ModelBuildingRequest.VALIDATION_LEVEL_MAVEN_3_1);

        assertViolations(result31, 0, 0, 3);

It will be called by **FastAPI** whenever it receives a request to the URL "`/`" using a `GET` operation.

In this case, it is an `async` function.

---

You could also define it as a normal function instead of `async def`:

{* ../../docs_src/first_steps/tutorial003_py39.py hl[7] *}

/// note

If you don't know the difference, check the [Async: *"In a hurry?"*](../async.md#in-a-hurry){.internal-link target=_blank}.