## OpenAPI { #openapi }

OpenAPI (previously known as Swagger) is the open specification for building APIs (now part of the Linux Foundation).

**FastAPI** is based on **OpenAPI**.

That's what makes it possible to have multiple automatic interactive documentation interfaces, code generation, etc.

OpenAPI has a way to define multiple security "schemes".

Get working code on a personal branch with tests passing before you submit a PR:

```
./gradlew clean check
```

Please make every effort to follow existing conventions and style in order to keep the code as
readable as possible.

Contribute code changes through GitHub by forking the repository and sending a pull request. We
squash all pull requests on merge.


Gradle Setup
------------

```
$ cat local.properties

Get working code on a personal branch with tests passing before you submit a PR:

```
./gradlew clean check
```

Please make every effort to follow existing conventions and style in order to keep the code as
readable as possible.

Contribute code changes through GitHub by forking the repository and sending a pull request. We
squash all pull requests on merge.


Gradle Setup
------------

```
$ cat local.properties

import org.apache.maven.api.plugin.descriptor.PluginDescriptor;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;

/**
 * Verifies that subclasses from generated model classes are possible.
 */
class ExtendedPluginDescriptorTest {

    /**
     * A subclass of the generated class {@link PluginDescriptor} that adds an additional field.
     */

Try to avoid using bitter sarcasm or potentially passive-aggressive comments. If something is wrong, it's better to be direct (try to be gentle) than sarcastic.

Try to be as specific and objective as possible, avoid generalizations.

For conversations that are more difficult, for example to reject a PR, you can ask me (@tiangolo) to handle it directly.

    validations:
      required: true

  - type: input
    id: testgrid
    attributes:
      label: Testgrid link

  - type: textarea
    id: reason
    attributes:
      label: Reason for failure (if possible)

  - type: textarea
    id: additional
    attributes:
      label: Anything else we need to know?

  - type: textarea
    id: sigs
    attributes:
      label: Relevant SIG(s)

## Current Behavior
<!--- If describing a bug, tell us what happens instead of the expected behavior -->
<!--- If suggesting a change/improvement, explain the difference from current behavior -->

## Possible Solution
<!--- Not obligatory, but suggest a fix/reason for the bug, -->
<!--- or ideas how to implement the addition or change -->

## Steps to Reproduce (for bugs)

 * variety of sequences of the {@link Iterator#next}, {@link Iterator#hasNext} and {@link
 * Iterator#remove} operations. This utility takes the brute-force approach of trying <i>all</i>
 * possible sequences of these operations, up to a given number of steps. So, if the caller
 * specifies to use <i>n</i> steps, a total of <i>3^n</i> tests are actually performed.
 *

0002 0.554 responseBodyEnd
0002 0.554 connectionReleased
0002 0.554 callEnd
0001 0.624 responseBodyEnd
0001 0.624 connectionReleased
0001 0.624 callEnd
```

The `EventListener.Factory` also makes it possible to limit metrics to a subset of calls. This one captures metrics on a random 10%:

```java
class MetricsEventListener extends EventListener {
  private static final Factory FACTORY = new Factory() {

////

//// tab | Python 3.10+ non-Annotated

/// tip

Prefer to use the `Annotated` version if possible.

///

```Python
{!> ../../docs_src/app_testing/app_b_py310/main.py!}
```

////

//// tab | Python 3.8+ non-Annotated

/// tip

Prefer to use the `Annotated` version if possible.

///

```Python
{!> ../../docs_src/app_testing/app_b/main.py!}
```

////