Problems with loop processing in Zapier webhooks

Other Questions Zapier
1

I’m encountering an issue with handling nested data in my Zapier webhook. The version I tested locally runs without any problems, but the one in Zapier triggers errors.

Local Test Code:

var requestData = {
    "url": "api-url-goes-here",
    "action": "FETCH",
    "data": {
        "fields": ["FullName", "emailAddress", "DateCreated"],
        "records": [
            ["john_doe", "[email protected]", "15 Mar, 2018 10:22:30"],
            ["sarahk", "[email protected]", "15 Mar, 2018 14:45:12"]
        ]
    }
};

var outputRecords = [];

for (var i = 0; i < requestData.data.records.length; i++) {
    var record = {};
    for (var j = 0; j < requestData.data.fields.length; j++) {
        record[requestData.data.fields[j]] = requestData.data.records[i][j];
    }
    outputRecords.push(record);
}

console.log(outputRecords);

Desired Output:

{
  "FullName": "john_doe",
  "emailAddress": "[email protected]",
  "DateCreated": "15 Mar, 2018 10:22:30"
}{
  "FullName": "sarahk",
  "emailAddress": "[email protected]",
  "DateCreated": "15 Mar, 2018 14:45:12"
}

Trouble with Zapier Code:

data_poll: function(bundle){
  var response = z.JSON.parse(bundle.response.content);
  var outputRecords = [];

  for (var i = 0; i < response.data.records.length; i++) {
     var record = {};
     for (var j = 0; j < response.data.fields.length; j++) {
        record[response.data.fields[j]] = response.records[i][j];
     }
     outputRecords.push(record);
  }
  return outputRecords || [];
}

I’m receiving the error: TypeError: Cannot read property 'records' of undefined. What could be causing this issue with my Zapier code?

2

Classic property path inconsistency error. Hit something similar with Zapier’s data parsing last year. The issue isn’t just the missing .data reference others mentioned - there’s also how Zapier handles response structure differently than your local environment. Zapier sometimes wraps or unwraps response data in weird ways. I’d add some defensive logging first: console.log(JSON.stringify(response)) at the top of your function to see exactly what structure you’re getting. Also throw in null checks like if (!response || !response.data || !response.data.records) before your loops. API response format sometimes changes slightly between local testing and Zapier’s execution environment, especially with webhook timing.

3

simple typo in your inner loop. you’ve got response.records[i][j] but it should be response.data.records[i][j] - you’re missing the .data part. you’re accessing fields correctly with response.data.fields but forgot to add .data for the record values. that’s why you’re getting the undefined error - response.records doesn’t exist.

4

Had this exact same issue a few months back with nested API responses in Zapier. Your problem is in the nested loop - you’re using response.records[i][j] instead of response.data.records[i][j]. You correctly access response.data.records.length and response.data.fields.length in your loop conditions, but then drop the .data when accessing the actual record values. That’s what’s causing the undefined error - response.records doesn’t exist, only response.data.records does. Change it to record[response.data.fields[j]] = response.data.records[i][j]; and you’re good. Spent hours debugging this same typo because it’s so easy to miss with deeply nested objects.