Is there a way for a lambda function to know if it was invoked synchronously or async

DevOps AWS
#1

Hello everyone… :wave:

Quick question here… Is there a way for a lambda function to know if it was invoked synchronously (RequestResponse) or async (Event) inside the lambda code?

Thanks

#2

You could possibly rely on the ClientContext object in the context object passed to the handler.

You can invoke a function synchronously (and wait for the response), or asynchronously. By default, Lambda invokes your function synchronously (i.e. theInvocationType is RequestResponse). To invoke a function asynchronously, set InvocationType to Event. Lambda passes the ClientContext object to your function for synchronous invocations only.

#3

Lack of a client context could mean it’s async, but I’m not sure how reliable that is.

#4

https://docs.aws.amazon.com/lambda/latest/dg/API_Invoke.html

#5

I have a little code that looks at the shape of the request and can discern between the different event types I support (API Gateway, SNS, SQS)

#6

is that code public? :grin: :crossed_fingers: