### Hey API { #hey-api }

Once we have a FastAPI app with the models, we can use Hey API to generate a TypeScript client. The fastest way to do that is via npx.

```sh
npx @hey-api/openapi-ts -i http://localhost:8000/openapi.json -o src/client
```

This will generate a TypeScript SDK in `./src/client`.

There are some additional dependencies you might want to install.

Additional optional Pydantic dependencies:

* <a href="https://docs.pydantic.dev/latest/usage/pydantic_settings/" target="_blank"><code>pydantic-settings</code></a> - for settings management.
* <a href="https://docs.pydantic.dev/latest/usage/types/extra_types/extra_types/" target="_blank"><code>pydantic-extra-types</code></a> - for extra types to be used with Pydantic.

* Seriously impressive performance. It is <a href="https://github.com/encode/starlette#performance" class="external-link" target="_blank">one of the fastest Python frameworks available, on par with **NodeJS** and **Go**</a>.
* **WebSocket** support.
* In-process background tasks.
* Startup and shutdown events.
* Test client built on HTTPX.

It clearly inspired Uvicorn and Starlette, that are currently faster than Sanic in open benchmarks.

///

/// check | Inspired **FastAPI** to

Find a way to have a crazy performance.

That's why **FastAPI** is based on Starlette, as it is the fastest framework available (tested by third-party benchmarks).

///

There are some additional dependencies you might want to install.

Additional optional Pydantic dependencies:

* <a href="https://docs.pydantic.dev/latest/usage/pydantic_settings/" target="_blank"><code>pydantic-settings</code></a> - for settings management.
* <a href="https://docs.pydantic.dev/latest/usage/types/extra_types/extra_types/" target="_blank"><code>pydantic-extra-types</code></a> - for extra types to be used with Pydantic.

1) For relative URLs, only translate link text. Do not translate the URL or its parts

Example:

    Source (English):

        «««
        [One of the fastest Python frameworks available](#performance)
        »»»

    Result (German):

        «««
        [Eines der schnellsten verfügbaren Python-Frameworks](#performance)
        »»»

package okhttp3.internal

import assertk.assertThat
import assertk.assertions.isEqualTo
import assertk.assertions.isNull
import java.util.concurrent.atomic.AtomicReference
import org.junit.jupiter.api.Test

class TagsTest {
  @Test
  fun emptyTags() {
    val tags = EmptyTags
    assertThat(tags[String::class]).isNull()
  }

  @Test
  fun singleElement() {
    val tags = EmptyTags.plus(String::class, "hello")

 *
 * @author Kevin Bourrillion
 * @author Mike Bostock
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
@SuppressWarnings("JUnitIncompatibleType") // Many intentional violations here.
public class MapsTest extends TestCase {

  private static final Comparator<Integer> SOME_COMPARATOR = Collections.reverseOrder();

  public void testHashMap() {
    @SuppressWarnings("UseCollectionConstructor") // test of factory method

 *
 * @author Kevin Bourrillion
 * @author Mike Bostock
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
@SuppressWarnings("JUnitIncompatibleType") // Many intentional violations here.
public class MapsTest extends TestCase {

  private static final Comparator<Integer> SOME_COMPARATOR = Collections.reverseOrder();

  public void testHashMap() {
    @SuppressWarnings("UseCollectionConstructor") // test of factory method

    runs-on: ubuntu-latest
    steps:
      - name: Dump GitHub context
        env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
        run: echo "$GITHUB_CONTEXT"
      # pin to actions/checkout@v5 for compatibility with latest-changes
      # Ref: https://github.com/actions/checkout/issues/2313
      - uses: actions/checkout@v5
        with:
          # To allow latest-changes to commit to the main branch