entry := errToEntry(ctx, subsystem, err, errKind...)
	sendLog(ctx, entry)
}

func sendLog(ctx context.Context, entry log.Entry) {
	systemTgts := SystemTargets()
	if len(systemTgts) == 0 {
		return
	}

	// Iterate over all logger targets to send the log entry
	for _, t := range systemTgts {
		if err := t.Send(ctx, entry); err != nil {
			if consoleTgt != nil { // Sending to the console never fails

		last = defaultLogBufferCount
	}

	lastN = make([]log.Info, last)
	sys.RLock()
	sys.logBuf.Do(func(p any) {
		if p != nil {
			lg, ok := p.(log.Info)
			if ok && lg.SendLog(node, logKind) {
				lastN[cnt%last] = lg
				cnt++
			}
		}
	})
	sys.RUnlock()
	// send last n console log messages in order filtered by node
	if cnt > 0 {
		for i := range last {

	}
	var buf bytes.Buffer
	enc := json.NewEncoder(&buf)
	for {
		select {
		case entry, ok := <-ch:
			if !ok {
				return grid.NewRemoteErrString("console log channel closed")
			}
			if !entry.SendLog("", madmin.LogMask(mask)) {
				continue
			}
			buf.Reset()
			if err := enc.Encode(entry); err != nil {
				return grid.NewRemoteErr(err)
			}
			out <- grid.NewBytesWithCopyOf(buf.Bytes())

This includes, for example:

* Email notifications sent after performing an action:
    * As connecting to an email server and sending an email tends to be "slow" (several seconds), you can return the response right away and send the email notification in the background.
* Processing data:

		return err
	}
	if msg.Flags&FlagCRCxxh3 != 0 {
		h := xxh3.Hash(dst)
		dst = binary.LittleEndian.AppendUint32(dst, uint32(h))
	}
	return c.send(c.ctx, dst)
}

// sendMsg will send
func (c *Connection) sendMsg(conn net.Conn, msg message, payload msgp.MarshalSizer) error {
	if payload != nil {
		if sz := payload.Msgsize(); cap(msg.Payload) < sz {
			PutByteBuffer(msg.Payload)

func (m *muxClient) sendLocked(msg message) error {
	dst := GetByteBufferCap(msg.Msgsize())
	msg.Seq = m.SendSeq
	msg.MuxID = m.MuxID
	msg.Flags |= m.BaseFlags
	if debugPrint {
		fmt.Println("Client sending", &msg, "to", m.parent.Remote)
	}
	m.SendSeq++

	dst, err := msg.MarshalMsg(dst)
	if err != nil {
		return err
	}
	if msg.Flags&FlagSubroute != 0 {
		if m.subroute == nil {

{* ../../docs_src/dependencies/tutorial013_an_py310.py ln[19:21] *}

...would be run after the response finishes sending the slow data:

{* ../../docs_src/dependencies/tutorial013_an_py310.py ln[30:38] hl[31:33] *}

But as `generate_stream()` doesn't use the database session, it is not really necessary to keep the session open while sending the response.

It enables Brotli support in addition to tranparent Gzip support,
provided Accept-Encoding is not set previously.  Modern web servers
must choose to return Brotli responses.  n.b. It is not used for
sending requests.

```java
OkHttpClient client = new OkHttpClient.Builder()
  .addInterceptor(BrotliInterceptor.INSTANCE)
  .build();
```

```kotlin
implementation("com.squareup.okhttp3:okhttp-brotli:5.3.0")
```

Being able to use asynchronous functions in your tests could be useful, for example, when you're querying your database asynchronously. Imagine you want to test sending requests to your FastAPI application and then verify that your backend successfully wrote the correct data in the database, while using an async database library.

Let's look at how we can make that work.

# OpenAPI Webhooks { #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**.