All the **logic** about how to register the URLs for webhooks and the code to actually send those requests is up to you. You write it however you want to in **your own code**.

## Documenting webhooks with **FastAPI** and OpenAPI { #documenting-webhooks-with-fastapi-and-openapi }

2025-08-06

## Context

Our codebase uses `null` extensively to represent an absence of value or optionality of the argument.
We utilize nullness annotations in Java code and somewhat rely on IDE warnings to guide us.
However, the Java code we have is not fully annotated, which causes several consequences:
* IDE warnings can be misleading
* Redundant null checks may increase binary size, hurt performance, and increase cognitive load for readers

[corporate CLA]: https://cla.developers.google.com/about/google-corporate

## Building and Testing

The most reliable way to build and test Guava is:

```shell
./mvnw clean install
```

(Our benchmarks, however, are
[not set up to run easily externally][benchmarks-run].)

/// note

`PATCH` is less commonly used and known than `PUT`.

And many teams use only `PUT`, even for partial updates.

You are **free** to use them however you want, **FastAPI** doesn't impose any restrictions.

But this guide shows you, more or less, how they are intended to be used.

///

        if (!flattenEnabled) {
            // When flattening is disabled, treat non-POM projects like parent POMs
            // Apply only basic transformations without flattening dependency management
            // However, BOMs still need special handling to transform packaging from "bom" to "pom"
            if (isBom) {
                return buildBomWithoutFlatten(session, project, src);
            } else {

    assertThat(longIterator.hasNext()).isFalse();
  }

  public void testCopyOf_array_empty() {
    /*
     * We don't guarantee the same-as property, so we aren't obligated to test it. However, it's
     * useful in testing - when two things are the same then one can't have bugs the other doesn't.
     */
    assertThat(ImmutableLongArray.copyOf(new long[0])).isSameInstanceAs(ImmutableLongArray.of());
  }

Hardcore: `Yesterday, my friend wrote: "If you spell incorrectly correctly, you have spelled it incorrectly". To which I answered: "Correct, but 'incorrectly' is incorrectly not '"incorrectly"'"`

////

//// tab | Info

... However, quotes inside code snippets must stay as is.

////

## code blocks { #code-blocks }

//// tab | Test

A Bash code example...

```bash
# Print a greeting to the universe
echo "Hello universe"

    return builder.toString();
  }

  /**
   * Returns an immutable array containing the same values as {@code this} array. This is logically
   * a no-op, and in some circumstances {@code this} itself is returned. However, if this instance
   * is a {@link #subArray} view of a larger array, this method will copy only the appropriate range
   * of values, resulting in an equivalent array with a smaller memory footprint.
   */

    return builder.toString();
  }

  /**
   * Returns an immutable array containing the same values as {@code this} array. This is logically
   * a no-op, and in some circumstances {@code this} itself is returned. However, if this instance
   * is a {@link #subArray} view of a larger array, this method will copy only the appropriate range
   * of values, resulting in an equivalent array with a smaller memory footprint.
   */

All the same options are supported.

All the same `parameters`, `responses`, `dependencies`, `tags`, etc.

/// tip

In this example, the variable is called `router`, but you can name it however you want.

///

We are going to include this `APIRouter` in the main `FastAPI` app, but first, let's check the dependencies and another `APIRouter`.

## Dependencies { #dependencies }