How can I use go-anthropic for real-time text completion

The go-anthropic library supports streaming completions, which allows you to get real-time responses from the Anthropic API. This is done through the `CreateMessagesStream` method, which streams the completion response back to your application as it is generated, rather than waiting for the full response.

To use streaming completions, you can create a `MessagesRequest` and set the `Streaming` field to `true`:

go
client := anthropic.NewClient("your anthropic apikey")
resp, err := client.CreateMessagesStream(context.Background(), anthropic.MessagesRequest{
    Model:     anthropic.ModelClaude3Opus20240229,
    Streaming: true,
    Messages: []anthropic.Message{
        {
            Role: anthropic.RoleUser,
            Content: []anthropic.MessageContent{
                anthropic.NewTextMessageContent("What is the weather like today?"),
            },
        },
    },
    MaxTokens: 1000,
})
if err != nil {
    // handle error
}

for msg := range resp.Messages {
    fmt.Println(msg.Content.Text)
}

This will stream the completion response back to your application, allowing you to display the text as it is generated, rather than waiting for the full response.

The go-anthropic library also supports the use of "tools", which allow the AI to perform external actions and return the results back to the application. This can enable real-time interactions where the AI can look up information, perform calculations, or take other actions on behalf of the user.

Overall, the streaming and tool features in the go-anthropic library make it well-suited for building real-time applications that leverage the capabilities of the Anthropic Claude API.