Ytukyg

I'm passing GET parameters to an AWS API Gateway resource Endpoint ( LAMBDA_PROXY) with serverless.

The GET Parameters are in array annotation, eg. ?filter[someKey]=someValue, and the parameters are passed to the handler in the event object properly.

As soon as I try to apply an authorizer to that same endpoint (authorizer: AWS_IAM) and use Postman to send the correct Authorization info (AccesKey, SecretKey, SessionToken) with the same GET Request parameters, I'm receiving the following response:
StatusCode:
400 Bad Request
Headers:
x-amzn-ErrorType InvalidQueryStringException
Body:
{"message":null}

I couldn't find any good info on the InvalidQueryStringException from AWS.

Why are the GET request parameters properly passed to the handler without AWS_IAM authorizer but are rejected with AWS_IAM in place ?

Thank you for an insight on this.

Seems, that "percent-encoding" the square brackets is a way to get around the limitation of AWS API Gateway to not support square brackets as part of the query string, which is indeed a little odd.

So just "percent-encoding" the square bracket of the query string: ?filter[someKey]=someValue to ?filter%5BsomeKey%5D=someValue did actually help.

Besides, encoding the whole query string part, did not succeed (500, Internal Server Error), so you will very likely end up encoding just the square brackets.

Stackoverflow: AWS API gateway returns 400 error when square bracket (“[”, “]”) is in path
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