In your WebSocket route you can `await` for messages and send messages.

{* ../../docs_src/websockets/tutorial001_py39.py hl[48:52] *}

You can receive and send binary, text, and JSON data.

## Try it { #try-it }

If your file is named `main.py`, run your application with:

<div class="termy">

```console
$ fastapi dev main.py

     * @throws CIFSException if an error occurs retrieving the buffer size
     */
    int getSendBufferSize() throws CIFSException;

    /**
     * Gets the receive buffer size of the underlying SMB connection
     * @return the receive buffer size of the underlying connection
     * @throws CIFSException if an error occurs retrieving the buffer size
     */
    int getReceiveBufferSize() throws CIFSException;

    /**

{* ../../docs_src/body_updates/tutorial001_py310.py hl[28:33] *}

`PUT` is used to receive data that should replace the existing data.

### Warning about replacing { #warning-about-replacing }

That means that if you want to update the item `bar` using `PUT` with a body containing:

```Python
{

        assertNotNull(capabilities, "Capabilities should not be null");
        assertEquals(1, capabilities.size(), "TCP provider should only support send/receive");
        assertTrue(capabilities.contains(RdmaCapability.RDMA_SEND_RECEIVE), "Should support send/receive");
        assertFalse(capabilities.contains(RdmaCapability.RDMA_READ), "Should not support RDMA read");

  /**
   * {@inheritDoc}
   *
   * <p>Implementations may or may not support removal when a call to {@link #peek()} has occurred
   * since the most recent call to {@link #next()}.
   *
   * @throws IllegalStateException if there has been a call to {@link #peek()} since the most recent
   *     call to {@link #next()} and this implementation does not support this sequence of calls
   *     (optional)
   */
  @Override
  void remove();

If the client requests `http://example.com/items/foo` (an `item_id` `"foo"`), that client will receive an HTTP status code of 200, and a JSON response of:

```JSON
{
  "item": "The Foo Wrestlers"
}
```

But if the client requests `http://example.com/items/bar` (a non-existent `item_id` `"bar"`), that client will receive an HTTP status code of 404 (the "not found" error), and a JSON response of:

```JSON
{

    }

    /**
     * Get the maximum size for receive operations
     *
     * @return maximum receive size in bytes
     */
    public int getMaxReceiveSize() {
        return maxReceiveSize;
    }

    /**
     * Set the maximum size for receive operations
     *
     * @param maxReceiveSize maximum receive size in bytes
     */
    public void setMaxReceiveSize(int maxReceiveSize) {

 */
public class RdmaWorkRequest {

    /**
     * Type of RDMA work request
     */
    public enum RequestType {
        /** Send operation */
        SEND,
        /** Receive operation */
        RECEIVE,
        /** RDMA read operation */
        READ,
        /** RDMA write operation */
        WRITE
    }

    private final long requestId;
    private final RequestType type;

Un `Request` también tiene un `request.receive`, que es una función para "recibir" el cuerpo del request.

El `dict` `scope` y la función `receive` son ambos parte de la especificación ASGI.

Y esas dos cosas, `scope` y `receive`, son lo que se necesita para crear una nueva *Request instance*.

    /**
     * Default maximum number of receive credits
     */
    public static final int DEFAULT_RECEIVE_CREDIT_MAX = 255;

    /**
     * Default target number of send credits
     */
    public static final int DEFAULT_SEND_CREDIT_TARGET = 32;

    /**
     * Default maximum receive size (8KB)
     */
    public static final int DEFAULT_MAX_RECEIVE_SIZE = 8192;

    /**