1# Streaming — Go
2 
3## Streaming
4 
5```go
6stream := client.Messages.NewStreaming(context.Background(), anthropic.MessageNewParams{
7    Model:     anthropic.ModelClaudeOpus4_8,
8    MaxTokens: 64000,
9    Messages: []anthropic.MessageParam{
10        anthropic.NewUserMessage(anthropic.NewTextBlock("Write a haiku")),
11    },
12})
13 
14for stream.Next() {
15    event := stream.Current()
16    switch eventVariant := event.AsAny().(type) {
17    case anthropic.ContentBlockDeltaEvent:
18        switch deltaVariant := eventVariant.Delta.AsAny().(type) {
19        case anthropic.TextDelta:
20            fmt.Print(deltaVariant.Text)
21        }
22    }
23}
24if err := stream.Err(); err != nil {
25    log.Fatal(err)
26}
27```
28 
29**Accumulating the final message** (there is no `GetFinalMessage()` on the stream):
30 
31```go
32stream := client.Messages.NewStreaming(ctx, params)
33message := anthropic.Message{}
34for stream.Next() {
35    message.Accumulate(stream.Current())
36}
37if err := stream.Err(); err != nil { log.Fatal(err) }
38// message.Content now has the complete response
39```
40 
41 
42---
43 
44