Feature request: fill the request context from the ASGI scope in HttpResolverLocal

Use case

Our API runs behind a Lambda Function URL and its handlers read app.current_event.request_context.http.source_ip and .user_agent. Since 3.39 the same HttpResolverLocal app works both in Lambda and under uvicorn, which lets us drop a separate local Lambda emulator.

Under ASGI, though, HttpProxyEvent.from_asgi only copies the method, path, headers, body and query string:

powertools-lambda-python/aws_lambda_powertools/event_handler/http_resolver.py

Lines 108 to 141 in 67b73a5

    
               def from_asgi(cls, scope: Mapping[str, Any], body: bytes | None = None) -> HttpProxyEvent: 
        
                   """ 
        
                   Create an HttpProxyEvent from an ASGI scope dict. 
        
                   Parameters 
        
                   ---------- 
        
                   scope : dict 
        
                       ASGI scope dictionary 
        
                   body : bytes, optional 
        
                       Request body 
        
                   Returns 
        
                   ------- 
        
                   HttpProxyEvent 
        
                       Event object compatible with Powertools resolvers 
        
                   """ 
        
                   # Extract headers from ASGI format [(b"key", b"value"), ...] 
        
                   headers: dict[str, str] = {} 
        
                   for key, value in scope.get("headers", []): 
        
                       header_name = key.decode("utf-8").lower() 
        
                       header_value = value.decode("utf-8") 
        
                       # Handle duplicate headers by joining with comma 
        
                       if header_name in headers: 
        
                           headers[header_name] = f"{headers[header_name]}, {header_value}" 
        
                       else: 
        
                           headers[header_name] = header_value 
        
                   return cls( 
        
                       method=scope["method"], 
        
                       path=scope["path"], 
        
                       headers=headers, 
        
                       body=body, 
        
                       query_string=scope.get("query_string", b"").decode("utf-8"), 
        
                   )

The raw request context falls back to a stub with only stage, requestId and http.method/path:

powertools-lambda-python/aws_lambda_powertools/event_handler/http_resolver.py

Lines 90 to 95 in 67b73a5

    
           "requestContext": request_context 
        
           or { 
        
               "stage": "local", 
        
               "requestId": "local-request-id", 
        
               "http": {"method": method.upper(), "path": path}, 
        
           },

HttpProxyEvent also has no request_context property, so code that reads the caller's address or user agent from the request context raises AttributeError locally, even though the ASGI scope has client and the headers have user-agent.

Solution/User Experience

Fill the request context from the ASGI scope in from_asgi: the source IP from scope["client"] and the user agent from the user-agent header, and expose it on the local event, which today has no request_context property.

It would also help to let an app choose the local event shape, so an app written for HTTP API or Function URL events reads request_context.http locally the same way it does in Lambda.

Alternative solutions

We subclass `HttpResolverLocal`: `asgi_handler` keeps the client address in a ContextVar, and `_to_proxy_event` rebuilds the local event as a version 2.0 event with `requestContext.http` (method, path, sourceIp, userAgent, stage). It works, but it relies on the private `_to_proxy_event` and on `_state` for a typed `current_event`.

How we checked it, on 3.39.0: under uvicorn, current_event is an HttpProxyEvent with no request_context property, and its raw request context has only stage, requestId and http.method/path. With the subclass, the same app records the client address and user agent, and our existing tests still resolve version 2.0 Function URL events through it (realistic events in tests, not a deployed function).

This issue was drafted with an AI assistant.

Acknowledgment

This feature request meets Powertools for AWS Lambda (Python) Tenets
Should this be considered in other Powertools for AWS Lambda languages? i.e. Java, TypeScript, and .NET

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I like this. HttpResolverLocal under uvicorn should give handlers the same request_context fields they read in Lambda, at least http.source_ip, http.user_agent, http.method, http.path and the headers, filled from the ASGI scope. Anything Lambda-specific stays as it is today. Accepting for 3.42.0. Do you want to send the PR? You clearly know the code path.

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Feature request: fill the request context from the ASGI scope in HttpResolverLocal #8802

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	def from_asgi(cls, scope: Mapping[str, Any], body: bytes \| None = None) -> HttpProxyEvent:
	"""
	Create an HttpProxyEvent from an ASGI scope dict.

	Parameters
	----------
	scope : dict
	ASGI scope dictionary
	body : bytes, optional
	Request body

	Returns
	-------
	HttpProxyEvent
	Event object compatible with Powertools resolvers
	"""
	# Extract headers from ASGI format [(b"key", b"value"), ...]
	headers: dict[str, str] = {}
	for key, value in scope.get("headers", []):
	header_name = key.decode("utf-8").lower()
	header_value = value.decode("utf-8")
	# Handle duplicate headers by joining with comma
	if header_name in headers:
	headers[header_name] = f"{headers[header_name]}, {header_value}"
	else:
	headers[header_name] = header_value

	return cls(
	method=scope["method"],
	path=scope["path"],
	headers=headers,
	body=body,
	query_string=scope.get("query_string", b"").decode("utf-8"),
	)

	"requestContext": request_context
	or {
	"stage": "local",
	"requestId": "local-request-id",
	"http": {"method": method.upper(), "path": path},
	},

Feature request: fill the request context from the ASGI scope in HttpResolverLocal #8802

Description

Use case

Solution/User Experience

Alternative solutions

Acknowledgment

Activity

boring-cyborg commented on Nov 13, 2026

powertools-for-aws-oss-automation commented on Nov 13, 2026

leandrodamascena commented on Nov 15, 2026

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