ElasticAPM fails to process the context from authorizer

[brett-fitz]

Describe the bug:

[ERROR] AttributeError: 'dict' object has no attribute 'aws_request_id'
Traceback (most recent call last):
  File "/usr/local/lib/python3.12/importlib/__init__.py", line 90, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 999, in exec_module
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "/opt/threatintel/service.py", line 45, in <module>
    @handler
  File "/usr/local/lib/python3.12/site-packages/elasticapm/contrib/serverless/aws.py", line 111, in decorated
    with _lambda_transaction(func, name, client, event, context) as sls:
  File "/usr/local/lib/python3.12/site-packages/elasticapm/contrib/serverless/aws.py", line 257, in __enter__
    self.set_metadata_and_context(cold_start)
  File "/usr/local/lib/python3.12/site-packages/elasticapm/contrib/serverless/aws.py", line 313, in set_metadata_and_context
    faas["execution"] = self.context.aws_request_id

Interesting enough, when disabling Elastic APM (commenting out), the function runs successfully and the context does have a valid aws_request_id.

Context: LambdaContext([aws_request_id=056c5ea1-0f46-44e3-bd86-09743a79bafc,log_group_name=/aws/lambda/<REDACTED>,log_stream_name=2025/06/06/[$LATEST]<REDACTED>function_name=<REDACTED>memory_limit_in_mb=256,function_version=$LATEST,invoked_function_arn=arn:aws:lambda:us-east-1:<REDACTED>:function:<REDACTED>,client_context=None,identity=CognitoIdentity([cognito_identity_id=None,cognito_identity_pool_id=None]),tenant_id=None])

To Reproduce

1. Create a AWS Lambda function to be used as an AWS API Gateway Authorizer
2. Instrument with Elastic APM using capture_serverless() at entrypoint (handler)
3. Submit a request to your API Gateway that would invoke the authorizer
4. Observe error due to context missing value

Environment (please complete the following information)

• OS: [e.g. Linux] Debian (Docker image: python:3.12-slim)
• Python version: 3.12
• Framework and version [e.g. Django 2.1]: N/A
• APM Server version: 8.18.2
• Agent version: 6.23.0, Lambda extension: 1.5.8

Additional context

Add any other context about the problem here.

• Agent config options

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  remember to mask any sensitive fields like tokens
  

• requirements.txt:

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  replace this line with your `requirements.txt`
  

[xrmx]

Thanks for reporting, [ERROR] AttributeError: 'dict' object has no attribute 'aws_request_id' kinda suggest that self.context["aws_request_id"] would have worked? Or maybe that's just the internals of the LambdaContext class

[brett-fitz]

@xrmx Yea I think we could just add an type (isinstance) check and then access accordingly?

[brett-fitz]

Happy to submit a code update for this too but wanted to validate the bug first.

[xrmx]

@xrmx Yea I think we could just add an type (isinstance) check and then access accordingly?

Don't know yet, need to reproduce and sort out why LambdaContext is not what we expect