add AWS Go SDK v2 converse stream API sample to handle image input

gov2/bedrock-runtime/actions/converse_stream_image.go

@@ -0,0 +1,115 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package actions
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+
+	"github.com/aws/aws-sdk-go-v2/config"
+	"github.com/aws/aws-sdk-go-v2/service/bedrockruntime"
+	"github.com/aws/aws-sdk-go-v2/service/bedrockruntime/types"
+)
+
+const (
+	promptImage = `Describe what you see in this image in detail.`
+)
+
+func main() {
+	modelID := "us.anthropic.claude-3-7-sonnet-20250219-v1:0"
+	// load AWS configure
+	cfg, err := config.LoadDefaultConfig(context.TODO(),
+		config.WithRegion("us-west-2"), // replace your bedrock region
+	)
+	if err != nil {
+		log.Fatal("unable to load SDK configuration:", err)
+	}
+
+	// create bedrock runtime client
+	client := bedrockruntime.NewFromConfig(cfg)
+
+	// read image file
+	imagePath := "C:\\Users\\pc\\Downloads\\img.png" // Update with your image path
+	imageBytes, err := os.ReadFile(imagePath)
+	if err != nil {
+		log.Fatal("unable to read image:", err)
+	}
+
+	// create image block with format specified
+	imageBlock := types.ContentBlockMemberImage{
+		Value: types.ImageBlock{
+			Format: types.ImageFormatPng, // Add the format based on your image type
+			Source: &types.ImageSourceMemberBytes{
+				Value: imageBytes,
+			},
+		},
+	}
+
+	// create message
+	messages := types.Message{
+		Role: "user",
+		Content: []types.ContentBlock{
+			&types.ContentBlockMemberText{
+				Value: promptImage,
+			},
+			&imageBlock,
+		},
+	}
+
+	ctx := context.Background()
+
+	// Use ConverseStream instead of Converse
+	resp, err := client.ConverseStream(ctx, &bedrockruntime.ConverseStreamInput{
+		ModelId:  &modelID,
+		Messages: []types.Message{messages},
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	// Get the event stream
+	stream := resp.GetStream()
+	defer stream.Close()
+
+	fmt.Println("Streaming response:")
+	var fullResponse strings.Builder
+
+	// Process the streaming response
+	for event := range stream.Events() {
+		// Type switch to handle different event types
+		switch v := event.(type) {
+		case *types.ConverseStreamOutputMemberContentBlockDelta:
+			// Handle content block delta
+			if delta, ok := v.Value.Delta.(*types.ContentBlockDeltaMemberText); ok {
+				text := delta.Value
+				fmt.Print(text)
+				fullResponse.WriteString(text)
+			}
+		case *types.ConverseStreamOutputMemberMessageStop:
+			// Handle message stop event (contains usage info)
+			fmt.Println("\n\nMessage complete")
+		}
+	}
+
+	// Check for any errors that occurred during streaming
+	if err := stream.Err(); err != nil {
+		fmt.Printf("\nStream error: %v\n", err)
+	}
+
+	fmt.Println("\nDone streaming")
+	fmt.Printf("\nFull response:\n%s\n", fullResponse.String())
+}
+
+func printJSON(data interface{}) {
+	jsonBytes, err := json.MarshalIndent(data, "", "  ")
+	if err != nil {
+		log.Printf("Error marshaling JSON: %v", err)
+		return
+	}
+	log.Printf("\nJSON:\n%s\n", string(jsonBytes))
+}