The idea is that you would receive the payload and send it **directly** to an LLM provider, using a `prompt` to tell the LLM what to do, and return the response **as is**. No questions asked.

You don't even need to write the body of the function. The `@app.vibe()` decorator does everything for you based on AI vibes:

    Class<T> getType();

    /**
     * Creates a copy of the data suitable for storage in the cache. The original data to store can be mutated after the
     * cache is populated but the state of the cache must not change so we need to make a copy.
     *
     * @param data The data to store in the cache, must not be {@code null}.
     * @return The data being stored in the cache, never {@code null}.
     */
    T intoCache(T data);

    /**

# Extending OpenAPI { #extending-openapi }

There are some cases where you might need to modify the generated OpenAPI schema.

In this section you will see how.

## The normal process { #the-normal-process }

The normal (default) process, is as follows.

A `FastAPI` application (instance) has an `.openapi()` method that is expected to return the OpenAPI schema.

        // Directory leasing requires SMB 3.0 or higher
        // MS-SMB2: Level 2 leasing (which includes directory leasing) is only supported in SMB 3.0+
        // We'll validate this when we actually need to use the session

        // Request base lease
        Smb2LeaseKey leaseKey = baseLeaseManager.requestLease(directoryPath, requestedState);

        // Create directory cache entry

// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"context"
	"errors"
	"fmt"
	"io"
	"math/rand"
	"path"

        }

        override fun onMessage(
          webSocket: WebSocket,
          bytes: ByteString,
        ) {
          webSocket.send(bytes)
        }

        override fun onMessage(
          webSocket: WebSocket,
          text: String,
        ) {
          webSocket.send(text)
        }

        override fun onClosing(
          webSocket: WebSocket,
          code: Int,
          reason: String,

     *
     * @param cap the capability flag to check
     * @return whether capability is negotiated
     */
    boolean haveCapabilitiy(int cap);

    /**
     * Gets the negotiated send buffer size.
     *
     * @return the send buffer size
     */
    int getSendBufferSize();

    /**
     * Gets the negotiated receive buffer size.
     *
     * @return the receive buffer size
     */

# JSON with Bytes as Base64 { #json-with-bytes-as-base64 }

If your app needs to receive and send JSON data, but you need to include binary data in it, you can encode it as base64.

## Base64 vs Files { #base64-vs-files }

Consider first if you can use [Request Files](../tutorial/request-files.md) for uploading binary data and [Custom Response - FileResponse](./custom-response.md#fileresponse--fileresponse-) for sending binary data, instead of encoding it in JSON.

]
```

These are **JavaScript** objects, not strings, so you can't pass them from Python code directly.

* [Graphene](https://graphene-python.org/)
    * With [starlette-graphene3](https://github.com/ciscorn/starlette-graphene3)

## GraphQL with Strawberry { #graphql-with-strawberry }

If you need or want to work with **GraphQL**, [**Strawberry**](https://strawberry.rocks/) is the **recommended** library as it has the design closest to **FastAPI's** design, it's all based on **type annotations**.