Lambda Auth Function Error C# - Please Help

Question

Hi everyone,

I've created an Lambda Auth Function in C# to for basic authentication for REST APIs. However, once deployed and configured I'm receiving this error when doing a quick test in the AWS console:

***Authorizer result body before parsing: {"statusCode":200,"headers":{"Content-Type":"application/json"},"body":"{\"principalId\":\"User\",\"policyDocument\":{\"Version\":\"5/22/2024 12:56:02 PM +00:00\",\"Statement\":[{\"Effect\":\"Allow\",\"Action\":[\"execute-api:Invoke\"],\"Resource\":["ResourceHere"]}]}}","isBase64Encoded":false}  : Execution failed due to configuration error: Invalid JSON in response: Unrecognized field "statusCode", not marked as ignorable : AuthorizerConfigurationException***

Below is a quick example of the function:
``` cs
       public async Task MyFunction(APIGatewayProxyRequest request, ILambdaContext context)
       {
           request.Headers.TryGetValue("Authorization", out var credentials);
           
           // Do stuff

return new APIGatewayCustomAuthorizerResponse
            {
                PrincipalID = "enterHere",
                PolicyDocument = new APIGatewayCustomAuthorizerPolicy
                {
                    Version = "VersionNumber",
                    Statement = new List
                    {
                        new() {
                            Action = actions,
                            Effect = effect,
                            Resource = resources
                        }
                    }
                }
            };

}
```

From the error message, am I returning the correct output model or is there some configuration I haven't found?

The function tested fine using the Mock Lambda Tool.

Many thanks,

Dev-FP.

Accepted Answer

Just an update, I manage to resolve this by making a simple change to remove the async function.

Updated function is below should anyone else come across this issue.

``` cs
public APIGatewayCustomAuthorizerResponse MyFunction(APIGatewayProxyRequest request, ILambdaContext context)
       {
           request.Headers.TryGetValue("Authorization", out var credentials);
           
           // Do stuff

return new APIGatewayCustomAuthorizerResponse
            {
                PrincipalID = "enterHere",
                PolicyDocument = new APIGatewayCustomAuthorizerPolicy
                {
                    Statement = new List
                    {
                        new() {
                            Action = actions,
                            Effect = effect,
                            Resource = resources
                        }
                    }
                }
            };

}
```

Thanks for anyone who was taking a look.

Lambda Auth Function Error C# - Please Help

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