Loop over items issue

Questions
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1

Hello n8n Community,

I have a workflow where I’m running into an issue with the Loop Over Items node. I’ve observed that for n input items, the loop executes n + 1 times. This final, extra iteration doesn’t contain any data and is causing a downstream node in my workflow to crash.

My Workflow & The Problem

Here’s the basic structure of my flow:

  1. MongoDB Node: Retrieves exactly 100 items successfully.

  2. Loop Over Items Node: This is set to a batch size of 1 to process each item individually.

  3. Code Node (or any other node): This node is inside the loop and needs to process data from the item.

The loop correctly processes the 100 items. However, it then runs a 101st time . In this final run, it passes an empty item to my Code Node .

Inside my Code Node , I have a line like this:

Generated javascript

// Get the call_id from the current item in the loop
const callId = $('Loop Over Items').item.json.entry_point_call_id;

This code works perfectly for the first 100 iterations. On the 101st iteration, however, $(‘Loop Over Items’).item.json is undefined, which causes the workflow to fail with the error: TypeError: Cannot read properties of undefined (reading ‘entry_point_call_id’).

My Questions

  1. Why does the loop run this extra, empty time? Is this the intended and expected behavior?

  2. What is the standard, best-practice way in n8n to prevent this final empty iteration from crashing the workflow?

I’m looking for the most robust and recommended solution for handling this. Thank you

2

Loop over Items always executes this way - one for each item provided and once more - when it comes back to the loop node (after the last item), where it determines no more input and the workflow takes the “done” branch.

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