When building web APIs with FastAPI, if there's an error in our code, FastAPI will normally contain it to the single request that triggered the error. 🛡

The client will get a **500 Internal Server Error** for that request, but the application will continue working for the next requests instead of just crashing completely.

### Bigger Errors - Crashes

On the other side, there are thousands of users in the chat systems, so there's a high chance you'll find someone to talk to there, almost all the time. 😄

## Sponsor the author

You can also financially support the author (me) through <a href="https://github.com/sponsors/tiangolo" class="external-link" target="_blank">GitHub sponsors</a>.

There you could buy me a coffee ☕️ to say thanks. 😄

When I used to read fairy-tales, I fancied that kind of thing
never happened, and now here I am in the middle of one!  There
ought to be a book written about me, that there ought!  And when
I grow up, I'll write one--but I'm grown up now,' she added in a
sorrowful tone; `at least there's no room to grow up any more
HERE.'

  `But then,' thought Alice, `shall I NEVER get any older than I

When I used to read fairy-tales, I fancied that kind of thing
never happened, and now here I am in the middle of one!  There
ought to be a book written about me, that there ought!  And when
I grow up, I'll write one--but I'm grown up now,' she added in a
sorrowful tone; `at least there's no room to grow up any more
HERE.'

  `But then,' thought Alice, `shall I NEVER get any older than I

	// ErrDuplicatedKey occurs when there is a unique key constraint violation
	ErrDuplicatedKey = errors.New("duplicated key not allowed")
	// ErrForeignKeyViolated occurs when there is a foreign key constraint violation
	ErrForeignKeyViolated = errors.New("violates foreign key constraint")
	// ErrCheckConstraintViolated occurs when there is a check constraint violation

    id: help
    attributes:
      label: Commit to Help
      description: |
        After submitting this, I commit to one of:

          * Read open questions until I find 2 where I can help someone and add a comment to help there.
          * I already hit the "watch" button in this repository to receive notifications and I commit to help at least 2 people that ask questions in the future.

# OpenAPI Webhooks

There are cases where you want to tell your API **users** that your app could call *their* app (sending a request) with some data, normally to **notify** of some type of **event**.

This means that instead of the normal process of your users sending requests to your API, it's **your API** (or your app) that could **send requests to their system** (to their API, their app).

This is normally called a **webhook**.

## Webhooks steps

            bufferIndex += byteCount;
        }

        /*
         * if there is an andx and it itself is an andx then just recur by
         * calling this method for it. otherwise just read it's parameter words
         * and bytes as usual. Note how we can't just call andx.readWireFormat
         * because there's no header.
         */

        if( errorCode != 0 || andxCommand == (byte)0xFF ) {

     */
    @Nonnull
    <T> Optional<T> lookupOptional(Class<T> type, String name);

    /**
     * Performs a collection lookup for given typed components.
     *
     * @param type The component type.
     * @return The list of components. The list may be empty if no components found.
     * @param <T> The component type.

Downloading and installing the package dependencies **could take minutes**, but using the **cache** would **take seconds** at most.

And as you would be building the container image again and again during development to check that your code changes are working, there's a lot of accumulated time this would save.