ConverseStream - Amazon Bedrock


Sends messages to the specified Amazon Bedrock model and returns the response in a stream. ConverseStream provides a consistent API that works with all Amazon Bedrock models that support messages. This allows you to write code once and use it with different models. Should a model have unique inference parameters, you can also pass those unique parameters to the model.

To find out if a model supports streaming, call GetFoundationModel and check the responseStreamingSupported field in the response.


The AWS CLI doesn't support streaming operations in Amazon Bedrock, including ConverseStream.

Amazon Bedrock doesn't store any text, images, or documents that you provide as content. The data is only used to generate the response.

For information about the Converse API, see Use the Converse API. To use a guardrail, see Use a guardrail with the Converse API. To use a tool with a model, see Tool use (Function calling).

For example code, see Conversation streaming example.

This operation requires permission for the bedrock:InvokeModelWithResponseStream action.

Request Syntax

POST /model/modelId/converse-stream HTTP/1.1 Content-type: application/json { "additionalModelRequestFields": JSON value, "additionalModelResponseFieldPaths": [ "string" ], "guardrailConfig": { "guardrailIdentifier": "string", "guardrailVersion": "string", "streamProcessingMode": "string", "trace": "string" }, "inferenceConfig": { "maxTokens": number, "stopSequences": [ "string" ], "temperature": number, "topP": number }, "messages": [ { "content": [ { ... } ], "role": "string" } ], "system": [ { ... } ], "toolConfig": { "toolChoice": { ... }, "tools": [ { ... } ] } }

URI Request Parameters

The request uses the following URI parameters.


The ID for the model.

The modelId to provide depends on the type of model that you use:

Length Constraints: Minimum length of 1. Maximum length of 2048.

Pattern: ^(arn:aws(-[^:]+)?:bedrock:[a-z0-9-]{1,20}:(([0-9]{12}:custom-model/[a-z0-9-]{1,63}[.]{1}[a-z0-9-]{1,63}/[a-z0-9]{12})|(:foundation-model/[a-z0-9-]{1,63}[.]{1}[a-z0-9-]{1,63}([.:]?[a-z0-9-]{1,63}))|([0-9]{12}:provisioned-model/[a-z0-9]{12})))|([a-z0-9-]{1,63}[.]{1}[a-z0-9-]{1,63}([.:]?[a-z0-9-]{1,63}))|(([0-9a-zA-Z][_-]?)+)$

Required: Yes

Request Body

The request accepts the following data in JSON format.


Additional inference parameters that the model supports, beyond the base set of inference parameters that ConverseStream supports in the inferenceConfig field.

Type: JSON value

Required: No


Additional model parameters field paths to return in the response. ConverseStream returns the requested fields as a JSON Pointer object in the additionalModelResponseFields field. The following is example JSON for additionalModelResponseFieldPaths.

[ "/stop_sequence" ]

For information about the JSON Pointer syntax, see the Internet Engineering Task Force (IETF) documentation.

ConverseStream rejects an empty JSON Pointer or incorrectly structured JSON Pointer with a 400 error code. if the JSON Pointer is valid, but the requested field is not in the model response, it is ignored by ConverseStream.

Type: Array of strings

Array Members: Minimum number of 0 items. Maximum number of 10 items.

Length Constraints: Minimum length of 1. Maximum length of 256.

Required: No


Configuration information for a guardrail that you want to use in the request.

Type: GuardrailStreamConfiguration object

Required: No


Inference parameters to pass to the model. ConverseStream supports a base set of inference parameters. If you need to pass additional parameters that the model supports, use the additionalModelRequestFields request field.

Type: InferenceConfiguration object

Required: No


The messages that you want to send to the model.

Type: Array of Message objects

Required: Yes


A system prompt to send to the model.

Type: Array of SystemContentBlock objects

Required: No


Configuration information for the tools that the model can use when generating a response.


This field is only supported by Anthropic Claude 3 models.

Type: ToolConfiguration object

Required: No

Response Syntax

HTTP/1.1 200 Content-type: application/json { "contentBlockDelta": { "contentBlockIndex": number, "delta": { ... } }, "contentBlockStart": { "contentBlockIndex": number, "start": { ... } }, "contentBlockStop": { "contentBlockIndex": number }, "internalServerException": { }, "messageStart": { "role": "string" }, "messageStop": { "additionalModelResponseFields": JSON value, "stopReason": "string" }, "metadata": { "metrics": { "latencyMs": number }, "trace": { "guardrail": { "inputAssessment": { "string" : { "contentPolicy": { "filters": [ { "action": "string", "confidence": "string", "type": "string" } ] }, "contextualGroundingPolicy": { "filters": [ { "action": "string", "score": number, "threshold": number, "type": "string" } ] }, "sensitiveInformationPolicy": { "piiEntities": [ { "action": "string", "match": "string", "type": "string" } ], "regexes": [ { "action": "string", "match": "string", "name": "string", "regex": "string" } ] }, "topicPolicy": { "topics": [ { "action": "string", "name": "string", "type": "string" } ] }, "wordPolicy": { "customWords": [ { "action": "string", "match": "string" } ], "managedWordLists": [ { "action": "string", "match": "string", "type": "string" } ] } } }, "modelOutput": [ "string" ], "outputAssessments": { "string" : [ { "contentPolicy": { "filters": [ { "action": "string", "confidence": "string", "type": "string" } ] }, "contextualGroundingPolicy": { "filters": [ { "action": "string", "score": number, "threshold": number, "type": "string" } ] }, "sensitiveInformationPolicy": { "piiEntities": [ { "action": "string", "match": "string", "type": "string" } ], "regexes": [ { "action": "string", "match": "string", "name": "string", "regex": "string" } ] }, "topicPolicy": { "topics": [ { "action": "string", "name": "string", "type": "string" } ] }, "wordPolicy": { "customWords": [ { "action": "string", "match": "string" } ], "managedWordLists": [ { "action": "string", "match": "string", "type": "string" } ] } } ] } } }, "usage": { "inputTokens": number, "outputTokens": number, "totalTokens": number } }, "modelStreamErrorException": { }, "throttlingException": { }, "validationException": { } }

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.


The messages output content block delta.

Type: ContentBlockDeltaEvent object


Start information for a content block.

Type: ContentBlockStartEvent object


Stop information for a content block.

Type: ContentBlockStopEvent object


An internal server error occurred. Retry your request.

Type: Exception

HTTP Status Code: 500

Message start information.

Type: MessageStartEvent object


Message stop information.

Type: MessageStopEvent object


Metadata for the converse output stream.

Type: ConverseStreamMetadataEvent object


A streaming error occurred. Retry your request.

Type: Exception

HTTP Status Code: 424

The number of requests exceeds the limit. Resubmit your request later.

Type: Exception

HTTP Status Code: 429

Input validation failed. Check your request parameters and retry the request.

Type: Exception

HTTP Status Code: 400


For information about the errors that are common to all actions, see Common Errors.


The request is denied because of missing access permissions.

HTTP Status Code: 403


An internal server error occurred. Retry your request.

HTTP Status Code: 500


The request failed due to an error while processing the model.

HTTP Status Code: 424


The model specified in the request is not ready to serve inference requests.

HTTP Status Code: 429


The request took too long to process. Processing time exceeded the model timeout length.

HTTP Status Code: 408


The specified resource ARN was not found. Check the ARN and try your request again.

HTTP Status Code: 404


Your request was throttled because of service-wide limitations. Resubmit your request later or in a different region. You can also purchase Provisioned Throughput to increase the rate or number of tokens you can process.

HTTP Status Code: 429


Input validation failed. Check your request parameters and retry the request.

HTTP Status Code: 400


Send a message to a model and stream the response.

Send a message to Anthropic Claude Sonnet with ConverseStream and stream the response.

POST /model/anthropic.claude-3-sonnet-20240229-v1:0/converse-stream HTTP/1.1 { "messages": [ { "role": "user", "content": [ { "text": "Write an article about impact of high inflation to GDP of a country" } ] } ], "system": [{"text" : "You are an economist with access to lots of data"}], "inferenceConfig": { "maxTokens": 1000, "temperature": 0.5 } }

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: