Python Authorizer with API Gateway

I am trying to make a custom python authorizer with payload format 2.0, right now I’m keeping it really simple and just returning the json "{isAuthorized:true}" regardless of what token is presented.

However, I am still getting failures in cloudwatch saying that the format is incorrect..

I’ve tried "isAuthorized" as a simple response as well.

I am using the Simple response mode.

Here is the simple python authorizer:

import os
import re
import json
import logging
import base64
import boto3

def lambda_handler(event, context):
    try:
        response = "{isAuthorized:True}"
        y = json.dumps(response)
        return y;
    except:
        return "";

I’ve also tried it without the json.dumps like this:

...
try: 
    response = {"isAuthorized": True}
    return response;
...

Here’s the error in CloudWatch:

The response from the Lambda Authorizer function doesn't match the format that API Gateway expects. Simple response did not include 'isAuthorized'

Any idea what I’m doing wrong?