Sometime it works ane sometime it not, I am trying to get the 3-4 node back data, most of the time it can able to capture and sometime it is failed to do so, it says me it is “item linking errors” but this is pity much simple workflow how it can be linking item error [ERROR: Can’t determine which item to use], I am getting same error in more complex workflow as well !!
AI agent node version: 3.1
n8n version: 2.2.3
Using n8n cloud
Welcome to the forum @peace. This error isn’t “random” — it’s n8n’s item pairing biting you.
In your Update row in sheet node you use: {{ $(‘Loop Over Items’).item.json.row_number }}
When you reference another node with $('Node').item, n8n tries to find the paired item from that node that matches the current item (same lineage).
But in your workflow, nodes like AI Agent / Tools / Wait can sometimes drop or alter the pairing metadata (or change the item lineage). When that happens, n8n can’t figure out which “Loop Over Items” item matches the current item → so it throws:
[ERROR: Can’t determine which item to use]
“Paired item data … is unavailable…”
It can feel “sometimes works / sometimes doesn’t” because the AI/tool path can vary (tool called vs not, different internal execution path, etc.), which changes how pairing survives.
Stop reaching back 3–4 nodes. Carry the row_number forward and use $json.
With: {{ $json.row_number }}
Because Loop Over Items already outputs the current row item, and that row_number is already in the item flowing through your agent → code → wait → update chain.
This completely avoids item-linking.
Use index-based access instead of pairing:
{{ $items(‘Loop Over Items’, 0, $itemIndex).json.row_number }}
This tells n8n: “don’t try to pair; just use the same $itemIndex”.
Only safe if your flow preserves 1 item per loop iteration (which yours should).
This is also risky: {{ $(‘Get client’).isExecuted }}
Because Get client is an AI tool node, not a normal main-line node, and it may not be paired the way you expect.
Set a flag in your Code node (because Code node runs on the main item you’ll update):
Example Code node change:
for (const item of $input.all()) {
const isPass = item.json.output?.IsPass;
item.json.output.status =
isPass === 1 ? 'pass' :
isPass === 0 ? 'fail' : 'unknown';
// track tool usage in a stable way (whatever signal you prefer)
item.json.tool_used = !!item.json?.output?.toolUsed; // OR set it from agent output
}
return $input.all();
Then in Sheets update: {{ $json.tool_used }}
(You’ll need to decide what signal from the agent/tool output represents “tool used” in your data — but the key idea is: write it onto the item, don’t “reach sideways” across nodes.)
In Update row in sheet change row_number mapping to:
{{ $json.row_number }}
(Optional) If you still want a “back reference”, use:
{{ $items('Loop Over Items', 0, $itemIndex).json.row_number }}
Avoid $('SomeNode').item wherever possible inside loops + AI + wait chains.
Carry needed fields forward on $json.
If you paste the current incoming item JSON right before “Update row in sheet” (execute that node and copy the input), I can tell you exactly which fields are already present and the cleanest way to set tool_used without any fragile pairing.
I figure out, when it use Tool then only it give this kind of issue,
It means if I use AI agent and AI agent use tool then it will not possible to get the flow’s old data, this flow is managable with 2nd acion plan but I am facing this issue in more complex workflow where I can’t use 2nd method,
and I how can I pass row number through AI agent, I do not want it to be processed via AI agent, in this case identifer is number in other case identifer is a alphanumaric long id, and I try to pass it through AI agent and it change value a little and that caouse issue !!