TypeError: StoredFunction.__init__() got an unexpected keyword argument 'hmac_key'

[mcompen]

PySDK Version

• PySDK V2 (2.x)
• PySDK V3 (3.x)

Describe the bug
Upon using the step decorator, I receive errors supposedly at function bootstrap time. The logs erroneously indicate the step was run successfully.

To reproduce

from sagemaker.mlops.local.local_pipeline_session import LocalPipelineSession
from sagemaker.mlops.workflow.function_step import step
from sagemaker.mlops.workflow.pipeline import Pipeline


@step(
    image_uri="public.ecr.aws/sagemaker/sagemaker-distribution:3.7.0-cpu",
    instance_type="ml.m5.large",
)
def preprocess() -> None:
    print("Preprocessing step")


if __name__ == "__main__":
    name = "test"
    res_preprocess = preprocess()
    session = LocalPipelineSession()
    pipeline = Pipeline(
        name=name,
        steps=[preprocess()],
        sagemaker_session=session,
    )
    session.create_pipeline(pipeline=pipeline, pipeline_description="foo")
    session.start_pipeline_execution(PipelineName=name)

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots or logs
Remote:

local:

pzu6ht9kua-algo-1-frkcn  | /app/.venv/lib/python3.11/site-packages/sagemaker/train/remote_function/invoke_function.py:104: DeprecationWarning: sagemaker.train.remote_function.core.stored_function has been moved to sagemaker.core.remote_function.core.stored_function. Please update your imports. This shim will be removed in a future version.
pzu6ht9kua-algo-1-frkcn  |   from sagemaker.train.remote_function.core.stored_function import StoredFunction
pzu6ht9kua-algo-1-frkcn  | 2026-01-19 13:55:14,079 sagemaker.remote_function ERROR    Error encountered while invoking the remote function.
pzu6ht9kua-algo-1-frkcn  | Traceback (most recent call last):
pzu6ht9kua-algo-1-frkcn  |   File "/app/.venv/lib/python3.11/site-packages/sagemaker/train/remote_function/invoke_function.py", line 144, in main
pzu6ht9kua-algo-1-frkcn  |     _execute_remote_function(
pzu6ht9kua-algo-1-frkcn  |   File "/app/.venv/lib/python3.11/site-packages/sagemaker/train/remote_function/invoke_function.py", line 106, in _execute_remote_function
pzu6ht9kua-algo-1-frkcn  |     stored_function = StoredFunction(
pzu6ht9kua-algo-1-frkcn  |                       ^^^^^^^^^^^^^^^
pzu6ht9kua-algo-1-frkcn  | TypeError: StoredFunction.__init__() got an unexpected keyword argument 'hmac_key'
pzu6ht9kua-algo-1-frkcn exited with code 0
Aborting on container exit...
 Container pzu6ht9kua-algo-1-frkcn  Stopping
 Container pzu6ht9kua-algo-1-frkcn  Stopped
[01/19/26 14:55:15] INFO     ===== Job Complete =====                                                                               image.py:323
[01/19/26 14:55:16] INFO     Pipeline step 'preprocess-1e842e1e-0a59-4828-8c6c-7bb549f0600d' SUCCEEDED.                 pipeline_entities.py:180
                    INFO     Pipeline execution eb1dabc4-48b3-4e79-b6e5-229d92df098e SUCCEEDED  

System information
A description of your system. Please provide:

• SageMaker Python SDK version: 3.3.1
• Framework name (eg. PyTorch) or algorithm (eg. KMeans): n/a
• Framework version: n/a
• Python version: 3.11
• CPU or GPU: cpu
• Custom Docker image (Y/N): N

Additional context
It appears l.110 in invoke_function.py is the source of the bug: https://github.com/aws/sagemaker-python-sdk/blob/master/sagemaker-train/src/sagemaker/train/remote_function/invoke_function.py#L110

[nkmglobalp]

+1 I also faced same issue