Prompt caching does not work, cachePoint object not supported

[ShaharZivanOnvego]

To use prompt caching, according to the AWS Bedrock documentation, the system message needs to look like this:

...
  "system": [ 
    {
        "text": "You are an app that creates play lists for a radio station that plays rock and pop music. Only return song names and the artist. "
    },
    {
        "cachePoint": {
            "type": "default"
        }
    }
  ],
...

However, when trying to do this as a SystemMessage through Langchain, I get the following error:

System message must be a string, instead was: <class 'list'> Traceback (most recent call last):
  File "/home/shahar/ProjectData/AgentFramework/onvego/agent_framework/task_handler/internal.py", line 318, in __call__

If I initialize ChatBedrock with the flag beta_use_converse_api=True, then it does let me send a list - but when this list has the cachepoint object as specified:

{
    "cachePoint": {
        "type": "default",
    }
}

I get an error stating:

Parameter validation failed:
Unknown parameter in system[1]: "cachePoint", must be one of: text, guardContent

This seems to make cache prompting impossible, unless I am missing something.

[stanyq4]

As the number of our tools is constantly growing, we are also looking to utilize cachePoint param.

Is there any update on when this might be available? Sound like it should be a minor fix.

Thank you

[masquare]

Amazon Bedrock prompt caching is still in preview and as such, the new cachePoint parameter for system messages is not yet supported by botocore (see here).

We need botocore/boto3 to support the cachePoint parameter for system messages before langchain-aws can integrate it.

Tracking the boto3 release in boto/boto3#4376