# Send a message with the ConverseStream API
The following code examples show how to send a text message to Amazon Nova, using Bedrock's Converse API and process the response stream in real-time.
------
#### [ .NET ]
**SDK for .NET**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/Bedrock-runtime#code-examples).
Send a text message to Amazon Nova, using Bedrock's Converse API and process the response stream in real-time.
```
// Use the Converse API to send a text message to Amazon Nova
// and print the response stream.
using System;
using System.Collections.Generic;
using System.Linq;
using Amazon;
using Amazon.BedrockRuntime;
using Amazon.BedrockRuntime.Model;
// Create a Bedrock Runtime client in the AWS Region you want to use.
var client = new AmazonBedrockRuntimeClient(RegionEndpoint.USEast1);
// Set the model ID, e.g., Amazon Nova Lite.
var modelId = "amazon.nova-lite-v1:0";
// Define the user message.
var userMessage = "Describe the purpose of a 'hello world' program in one line.";
// Create a request with the model ID, the user message, and an inference configuration.
var request = new ConverseStreamRequest
{
ModelId = modelId,
Messages = new List
{
new Message
{
Role = ConversationRole.User,
Content = new List { new ContentBlock { Text = userMessage } }
}
},
InferenceConfig = new InferenceConfiguration()
{
MaxTokens = 512,
Temperature = 0.5F,
TopP = 0.9F
}
};
try
{
// Send the request to the Bedrock Runtime and wait for the result.
var response = await client.ConverseStreamAsync(request);
// Extract and print the streamed response text in real-time.
foreach (var chunk in response.Stream.AsEnumerable())
{
if (chunk is ContentBlockDeltaEvent)
{
Console.Write((chunk as ContentBlockDeltaEvent).Delta.Text);
}
}
}
catch (AmazonBedrockRuntimeException e)
{
Console.WriteLine($"ERROR: Can't invoke '{modelId}'. Reason: {e.Message}");
throw;
}
```
+ For API details, see [ConverseStream](https://docs.aws.amazon.com/goto/DotNetSDKV3/bedrock-runtime-2023-09-30/ConverseStream) in *AWS SDK for .NET API Reference*.
------
#### [ Java ]
**SDK for Java 2.x**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/bedrock-runtime#code-examples).
Send a text message to Amazon Nova using Bedrock's Converse API and process the response stream in real-time.
```
import software.amazon.awssdk.auth.credentials.DefaultCredentialsProvider;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.bedrockruntime.BedrockRuntimeAsyncClient;
import software.amazon.awssdk.services.bedrockruntime.model.*;
import java.util.concurrent.ExecutionException;
/**
* This example demonstrates how to use the Amazon Nova foundation models with an
* asynchronous Amazon Bedrock runtime client to generate streaming text responses.
* It shows how to:
* - Set up the Amazon Bedrock runtime client
* - Create a message
* - Configure a streaming request
* - Set up a stream handler to process the response chunks
* - Process the streaming response
*/
public class ConverseStream {
public static void converseStream() {
// Step 1: Create the Amazon Bedrock runtime client
// The runtime client handles the communication with AI models on Amazon Bedrock
BedrockRuntimeAsyncClient client = BedrockRuntimeAsyncClient.builder()
.credentialsProvider(DefaultCredentialsProvider.create())
.region(Region.US_EAST_1)
.build();
// Step 2: Specify which model to use
// Available Amazon Nova models and their characteristics:
// - Amazon Nova Micro: Text-only model optimized for lowest latency and cost
// - Amazon Nova Lite: Fast, low-cost multimodal model for image, video, and text
// - Amazon Nova Pro: Advanced multimodal model balancing accuracy, speed, and cost
//
// For the latest available models, see:
// https://docs.aws.amazon.com/bedrock/latest/userguide/models-supported.html
String modelId = "amazon.nova-lite-v1:0";
// Step 3: Create the message
// The message includes the text prompt and specifies that it comes from the user
var inputText = "Describe the purpose of a 'hello world' program in one paragraph";
var message = Message.builder()
.content(ContentBlock.fromText(inputText))
.role(ConversationRole.USER)
.build();
// Step 4: Configure the request
// Optional parameters to control the model's response:
// - maxTokens: maximum number of tokens to generate
// - temperature: randomness (max: 1.0, default: 0.7)
// OR
// - topP: diversity of word choice (max: 1.0, default: 0.9)
// Note: Use either temperature OR topP, but not both
ConverseStreamRequest request = ConverseStreamRequest.builder()
.modelId(modelId)
.messages(message)
.inferenceConfig(config -> config
.maxTokens(500) // The maximum response length
.temperature(0.5F) // Using temperature for randomness control
//.topP(0.9F) // Alternative: use topP instead of temperature
).build();
// Step 5: Set up the stream handler
// The stream handler processes chunks of the response as they arrive
// - onContentBlockDelta: Processes each text chunk
// - onError: Handles any errors during streaming
var streamHandler = ConverseStreamResponseHandler.builder()
.subscriber(ConverseStreamResponseHandler.Visitor.builder()
.onContentBlockDelta(chunk -> {
System.out.print(chunk.delta().text());
System.out.flush(); // Ensure immediate output of each chunk
}).build())
.onError(err -> System.err.printf("Can't invoke '%s': %s", modelId, err.getMessage()))
.build();
// Step 6: Send the streaming request and process the response
// - Send the request to the model
// - Attach the handler to process response chunks as they arrive
// - Handle any errors during streaming
try {
client.converseStream(request, streamHandler).get();
} catch (ExecutionException | InterruptedException e) {
System.err.printf("Can't invoke '%s': %s", modelId, e.getCause().getMessage());
}
}
public static void main(String[] args) {
converseStream();
}
}
```
+ For API details, see [ConverseStream](https://docs.aws.amazon.com/goto/SdkForJavaV2/bedrock-runtime-2023-09-30/ConverseStream) in *AWS SDK for Java 2.x API Reference*.
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/bedrock-runtime#code-examples).
Send a text message to Amazon Nova using Bedrock's Converse API and process the response stream in real-time.
```
// This example demonstrates how to use the Amazon Nova foundation models
// to generate streaming text responses.
// It shows how to:
// - Set up the Amazon Bedrock runtime client
// - Create a message
// - Configure a streaming request
// - Process the streaming response
import {
BedrockRuntimeClient,
ConversationRole,
ConverseStreamCommand,
} from "@aws-sdk/client-bedrock-runtime";
// Step 1: Create the Amazon Bedrock runtime client
// Credentials will be automatically loaded from the environment
const client = new BedrockRuntimeClient({ region: "us-east-1" });
// Step 2: Specify which model to use
// Available Amazon Nova models and their characteristics:
// - Amazon Nova Micro: Text-only model optimized for lowest latency and cost
// - Amazon Nova Lite: Fast, low-cost multimodal model for image, video, and text
// - Amazon Nova Pro: Advanced multimodal model balancing accuracy, speed, and cost
//
// For the most current model IDs, see:
// https://docs.aws.amazon.com/bedrock/latest/userguide/models-supported.html
const modelId = "amazon.nova-lite-v1:0";
// Step 3: Create the message
// The message includes the text prompt and specifies that it comes from the user
const inputText =
"Describe the purpose of a 'hello world' program in one paragraph";
const message = {
content: [{ text: inputText }],
role: ConversationRole.USER,
};
// Step 4: Configure the streaming request
// Optional parameters to control the model's response:
// - maxTokens: maximum number of tokens to generate
// - temperature: randomness (max: 1.0, default: 0.7)
// OR
// - topP: diversity of word choice (max: 1.0, default: 0.9)
// Note: Use either temperature OR topP, but not both
const request = {
modelId,
messages: [message],
inferenceConfig: {
maxTokens: 500, // The maximum response length
temperature: 0.5, // Using temperature for randomness control
//topP: 0.9, // Alternative: use topP instead of temperature
},
};
// Step 5: Send and process the streaming request
// - Send the request to the model
// - Process each chunk of the streaming response
try {
const response = await client.send(new ConverseStreamCommand(request));
for await (const chunk of response.stream) {
if (chunk.contentBlockDelta) {
// Print each text chunk as it arrives
process.stdout.write(chunk.contentBlockDelta.delta?.text || "");
}
}
} catch (error) {
console.error(`ERROR: Can't invoke '${modelId}'. Reason: ${error.message}`);
process.exitCode = 1;
}
```
+ For API details, see [ConverseStream](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/bedrock-runtime/command/ConverseStreamCommand) in *AWS SDK for JavaScript API Reference*.
------
#### [ Kotlin ]
**SDK for Kotlin**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/bedrock-runtime#code-examples).
Send a text message to Amazon Nova using Bedrock's Converse API and process the response stream in real-time.
```
import aws.sdk.kotlin.services.bedrockruntime.BedrockRuntimeClient
import aws.sdk.kotlin.services.bedrockruntime.model.ContentBlock
import aws.sdk.kotlin.services.bedrockruntime.model.ConversationRole
import aws.sdk.kotlin.services.bedrockruntime.model.ConverseStreamOutput
import aws.sdk.kotlin.services.bedrockruntime.model.ConverseStreamRequest
import aws.sdk.kotlin.services.bedrockruntime.model.Message
/**
* This example demonstrates how to use the Amazon Nova foundation models
* to generate streaming text responses.
* It shows how to:
* - Set up the Amazon Bedrock runtime client
* - Create a message with a prompt
* - Configure a streaming request with parameters
* - Process the response stream in real time
*/
suspend fun main() {
converseStream()
}
suspend fun converseStream(): String {
// A buffer to collect the complete response
val completeResponseBuffer = StringBuilder()
// Create and configure the Bedrock runtime client
BedrockRuntimeClient { region = "us-east-1" }.use { client ->
// Specify the model ID. For the latest available models, see:
// https://docs.aws.amazon.com/bedrock/latest/userguide/models-supported.html
val modelId = "amazon.nova-lite-v1:0"
// Create the message with the user's prompt
val prompt = "Describe the purpose of a 'hello world' program in a paragraph."
val message = Message {
role = ConversationRole.User
content = listOf(ContentBlock.Text(prompt))
}
// Configure the request with optional model parameters
val request = ConverseStreamRequest {
this.modelId = modelId
messages = listOf(message)
inferenceConfig {
maxTokens = 500 // Maximum response length
temperature = 0.5F // Lower values: more focused output
// topP = 0.8F // Alternative to temperature
}
}
// Process the streaming response
runCatching {
client.converseStream(request) { response ->
response.stream?.collect { chunk ->
when (chunk) {
is ConverseStreamOutput.ContentBlockDelta -> {
// Process each text chunk as it arrives
chunk.value.delta?.asText()?.let { text ->
print(text)
System.out.flush() // Ensure immediate output
completeResponseBuffer.append(text)
}
}
else -> {} // Other output block types can be handled as needed
}
}
}
}.onFailure { error ->
error.message?.let { e -> System.err.println("ERROR: Can't invoke '$modelId'. Reason: $e") }
throw RuntimeException("Failed to generate text with model $modelId: $error", error)
}
}
return completeResponseBuffer.toString()
}
```
+ For API details, see [ConverseStream](https://sdk.amazonaws.com/kotlin/api/latest/index.html) in *AWS SDK for Kotlin API reference*.
------
#### [ Python ]
**SDK for Python (Boto3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/bedrock-runtime#code-examples).
Send a text message to Amazon Nova, using Bedrock's Converse API and process the response stream in real-time.
```
# Use the Conversation API to send a text message to Amazon Nova Text
# and print the response stream.
import boto3
from botocore.exceptions import ClientError
# Create a Bedrock Runtime client in the AWS Region you want to use.
client = boto3.client("bedrock-runtime", region_name="us-east-1")
# Set the model ID, e.g., Amazon Nova Lite.
model_id = "amazon.nova-lite-v1:0"
# Start a conversation with the user message.
user_message = "Describe the purpose of a 'hello world' program in one line."
conversation = [
{
"role": "user",
"content": [{"text": user_message}],
}
]
try:
# Send the message to the model, using a basic inference configuration.
streaming_response = client.converse_stream(
modelId=model_id,
messages=conversation,
inferenceConfig={"maxTokens": 512, "temperature": 0.5, "topP": 0.9},
)
# Extract and print the streamed response text in real-time.
for chunk in streaming_response["stream"]:
if "contentBlockDelta" in chunk:
text = chunk["contentBlockDelta"]["delta"]["text"]
print(text, end="")
except (ClientError, Exception) as e:
print(f"ERROR: Can't invoke '{model_id}'. Reason: {e}")
exit(1)
```
+ For API details, see [ConverseStream](https://docs.aws.amazon.com/goto/boto3/bedrock-runtime-2023-09-30/ConverseStream) in *AWS SDK for Python (Boto3) API Reference*.
------
#### [ Swift ]
**SDK for Swift**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/bedrock-runtime#code-examples).
Send a text message to Amazon Nova, using Bedrock's Converse API and process the response stream in real-time.
```
// An example demonstrating how to use the Conversation API to send a text message
// to Amazon Nova and print the response stream
import AWSBedrockRuntime
func printConverseStream(_ textPrompt: String) async throws {
// Create a Bedrock Runtime client in the AWS Region you want to use.
let config =
try await BedrockRuntimeClient.BedrockRuntimeClientConfiguration(
region: "us-east-1"
)
let client = BedrockRuntimeClient(config: config)
// Set the model ID.
let modelId = "amazon.nova-lite-v1:0"
// Start a conversation with the user message.
let message = BedrockRuntimeClientTypes.Message(
content: [.text(textPrompt)],
role: .user
)
// Optionally use inference parameters.
let inferenceConfig =
BedrockRuntimeClientTypes.InferenceConfiguration(
maxTokens: 512,
stopSequences: ["END"],
temperature: 0.5,
topp: 0.9
)
// Create the ConverseStreamInput to send to the model.
let input = ConverseStreamInput(
inferenceConfig: inferenceConfig, messages: [message], modelId: modelId)
// Send the ConverseStreamInput to the model.
let response = try await client.converseStream(input: input)
// Extract the streaming response.
guard let stream = response.stream else {
print("No stream available")
return
}
// Extract and print the streamed response text in real-time.
for try await event in stream {
switch event {
case .messagestart(_):
print("\nNova Lite:")
case .contentblockdelta(let deltaEvent):
if case .text(let text) = deltaEvent.delta {
print(text, terminator: "")
}
default:
break
}
}
}
```
+ For API details, see [ConverseStream](https://sdk.amazonaws.com/swift/api/awsbedrockruntime/latest/documentation/awsbedrockruntime/bedrockruntimeclient/conversestream(input:)) in *AWS SDK for Swift API reference*.
------