JSON returning with "\" (Lambda)

You're posting it as a string.

Try context.succeed(JSON.parse(result))

From the docs

The result provided must be JSON.stringify compatible. If AWS Lambda fails to stringify or encounters another error, an unhandled exception is thrown, with the X-Amz-Function-Error response header set to Unhandled.

http://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-context.html

So essentially it's taking your json string as a string and calling JSON.stringify on it...thus escaping all the quotes as you're seeing. Pass the parsed JSON object to succeed and it should not have this issue