Bedrock InvokeFlow unavailable boto3

Question

Hi AWS Community,

I’m encountering an issue with the Amazon Bedrock Runtime service where the InvokeFlow operation is not available when using the boto3 SDK. Here’s what I’ve done so far to troubleshoot the problem:

Steps I’ve Taken:
Checked Available Methods in boto3
I instantiated the Bedrock Runtime client using the following code:

python:
import boto3
bedrock_runtime = boto3.client('bedrock-runtime', region_name='eu-west-2')
print(dir(bedrock_runtime))

The dir() output lists methods like invoke_model and invoke_model_with_response_stream, but invoke_flow is not included.

Switched Regions
I tried switching regions to us-east-1, us-west-2, and eu-west-2 (all supported regions for Amazon Bedrock) by modifying the client initialization. The results were the same—invoke_flow is not listed as an available method.

Validated boto3 and Python Versions
I’m using Python 3.12.4 and the latest versions of boto3 and botocore:

bash
boto3==1.28.x
botocore==1.31.x

I confirmed the SDK is fully up-to-date.

Checked IAM Permissions
I verified my IAM user policy includes the necessary permissions:

json
{
    "Effect": "Allow",
    "Action": [
        "bedrock:InvokeFlow"
    ],
    "Resource": "*"
}

Confirmed Bedrock Access
I successfully invoked foundation models (e.g., amazon.titan-text-express-v1) using the invoke_model method. The service works as expected for other operations, indicating the Bedrock Runtime service is properly configured.

Explored SDK Limitations
Since the InvokeFlow API is documented in the Amazon Bedrock API Reference, it seems odd that the operation is not exposed in boto3.

Question:
Is the InvokeFlow operation supported in the current version of boto3? If not:

Is there a timeline for its inclusion?
Are there any alternative SDKs or recommended workarounds for invoking flows programmatically?
I’d appreciate any insights into whether this is an issue with my setup, the SDK version, or potential account restrictions.

Thank you for your help!

Riku_Kobayashi · Accepted Answer

Hello.

The "invoke_flow" API is included in "bedrock-agent-runtime" instead of "bedrock-runtime".  
So, please try changing the boto3 client creation method as follows.  
https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/bedrock-agent-runtime.html  
https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/bedrock-agent-runtime/client/invoke_flow.html  
```
import boto3

client = boto3.client('bedrock-agent-runtime')
```

re:Post Agent · Answer

The InvokeFlow operation is not currently supported in the boto3 SDK for Amazon Bedrock. This is not an issue with your setup or account restrictions, but rather a limitation of the current AWS CLI and SDK implementation for Bedrock.

The AWS CLI does not support streaming operations in Amazon Bedrock, including InvokeFlow. This limitation extends to the boto3 SDK, which is why you're not seeing the invoke_flow method in the available operations for the bedrock-runtime client.

At present, there is no official timeline provided for the inclusion of InvokeFlow in boto3. Amazon Bedrock is a relatively new service, and it's possible that support for InvokeFlow may be added in future updates to the SDK.

As for alternatives or workarounds, since InvokeFlow is part of the Amazon Bedrock API, you might consider using direct HTTP requests to the API endpoint if you need to use this operation in your application. This would involve manually constructing and sending HTTP requests to the appropriate Bedrock endpoint, handling authentication, and parsing the responses.

However, it's important to note that InvokeFlow is designed for streaming responses, which can be complex to handle without SDK support. If your use case allows, you might want to explore if other available methods in the boto3 SDK for Bedrock (such as invoke_model or invoke_model_with_response_stream) can meet your requirements until InvokeFlow is officially supported.

For the most up-to-date information on SDK support and potential workarounds, it would be advisable to check the official AWS documentation regularly or reach out to AWS Support for specific guidance on your use case.  
**Sources**  
[InvokeFlow - Amazon Bedrock](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent-runtime_InvokeFlow.html)  
[Community | AWS BedRock - Boto3 Demo - LLAMA2 Model](https://community.aws/content/2dVRLD3pySeHF1H6hXVZ9p36By6/aws-bedrock---boto3-demo---llama2-model)  
[Community | AWS BedRock - Boto3 Demo - Cohere Model](https://community.aws/content/2ZUnKHjaohOnRqShW21AYnYoXGq/aws-bedrock---boto3-demo---cohere-model)

Bedrock InvokeFlow unavailable boto3

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