```Python
q: Annotated[str, Query(default="rick")] = "morty"
```

...because it's not clear if the default value should be `"rick"` or `"morty"`.

So, you would use (preferably):

```Python
q: Annotated[str, Query()] = "rick"
```

...or in older code bases you will find:

```Python
q: str = Query(default="rick")
```

    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick")
        function ->> execute: execute function code
        execute ->> code: return the result
    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick", salutation="Mr.")
        function ->> execute: execute function code
        execute ->> code: return the result
    end

If a client tries to send some extra data, they will receive an **error** response.

For example, if the client tries to send the form fields:

* `username`: `Rick`
* `password`: `Portal Gun`
* `extra`: `Mr. Poopybutthole`

They will receive an error response telling them that the field `extra` is not allowed:

```json
{
    "detail": [
        {

data = {
    "plumbus": {"description": "Freshly pickled plumbus", "owner": "Morty"},
    "portal-gun": {"description": "Gun to create portals", "owner": "Rick"},
}


class OwnerError(Exception):
    pass


def get_username():
    try:
        yield "Rick"
    except OwnerError as e:
        raise HTTPException(status_code=400, detail=f"Owner error: {e}")


@app.get("/items/{item_id}")

This would mean that **FastAPI** would expect a body similar to:

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2,
    "tags": ["rock", "metal", "bar"],
    "image": {
        "url": "http://example.com/baz.jpg",
        "name": "The Foo live"
    }
}
```

Again, doing just that declaration, with **FastAPI** you get:

    img: https://fastapi.tiangolo.com/img/sponsors/dribia.png
bronze:
  - url: https://www.exoflare.com/open-source/?utm_source=FastAPI&utm_campaign=open_source
    title: Biosecurity risk assessments made easy.
    img: https://fastapi.tiangolo.com/img/sponsors/exoflare.png
  # - url: https://testdriven.io/courses/tdd-fastapi/
  #   title: Learn to build high-quality web apps with best practices

    * Normally, a token is set to expire after some time.
        * So, the user will have to log in again at some point later.
        * And if the token is stolen, the risk is less. It is not like a permanent key that will work forever (in most of the cases).
* The frontend stores that token temporarily somewhere.
* The user clicks in the frontend to go to another section of the frontend web app.

				}
			}
		}
		return ObjectInfo{}, toObjectErr(err, srcBucket, srcObject)
	}

	// List all online disks.
	onlineDisks, modTime, etag := listOnlineDisks(storageDisks, metaArr, errs, readQuorum)

	// Pick latest valid metadata.
	fi, err := pickValidFileInfo(ctx, metaArr, modTime, etag, readQuorum)
	if err != nil {
		return oi, toObjectErr(err, srcBucket, srcObject)
	}
	if fi.Deleted {
		if srcOpts.VersionID == "" {

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

with a JSON body of:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

then *your API* will process the invoice, and at some point later, send a callback request to the `callback_url` (the *external API*):

```

		err = reduceWriteQuorumErrs(ctx, errs, objectOpIgnoredErrs, writeQuorum)
	} else {
		err = reduceReadQuorumErrs(ctx, errs, objectOpIgnoredErrs, readQuorum)
	}
	if err != nil {
		return fi, nil, err
	}

	// Pick one from the first valid metadata.
	fi, err = pickValidFileInfo(ctx, partsMetadata, modTime, etag, quorum)
	return fi, partsMetadata, err
}