Malformed Lambda proxy response

Question

I am trying to access a Lambda function using a POST method. When I try to test the POST resource I put in the Request body
{"article_url": "http://technewstt.com/bd1108/"}

This makes the API Gateway respond with Execution failed due to configuration error: Malformed Lambda proxy response My code is below.

exports.handler = (event, context, callback) => {
//event = {"article_url": "http://technewstt.com/bd1108/"};
console.log(event.article_url);
var http = require('http');
var TextAPI = require('textapi');
var textapi = new TextAPI({
    application_id: "randomn numbers",
    application_key: "randomn numbers"
});
textapi.summarize({
    url: event.article_url,
    sentences_number: 3
}, function(error, response) {
if (error === null) {
    response.sentences.forEach(function(s) {
    console.log(s);
    //var body = JSON.parse(s);
    // TODO implement
    //callback(null, s);
    callback(null, {"statusCode": 200, "body":  JSON.stringify(s)});
    });
}

});

};

Please note that if I uncomment the second line the API gateway works fine.

Any help with this issue would be greatly appreciated.

Answer 1

You are using Lambda Proxy integration which always expects output of the format http://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-lambda-proxy-integrations.html#api-gateway-simple-proxy-for-lambda-output-format

"Malformed Lambda proxy response" is returned if the lambda response format is unexpected. You can enable logging with full request/responses which should show you the response being returned from lambda. Its likely there was an error in you lambda function which returned an error.