AI Agent - chat history error on using sessionId from previous node

[ypyly]

Describe the problem/error/question

Issue in a workflow with AI agent and agent memory.
What am I doing wrong?

What is the error message (if any)?

connect “Postgres Chat Memory” to “set_params” (same happens with simple memory)

Please share your workflow

Share the output returned by the last node

Information on your n8n setup

• n8n version: 1.9.2
• Database (default: SQLite): postgresql
• n8n EXECUTIONS_PROCESS setting (default: own, main): queue
• Running n8n via (Docker, npm, n8n cloud, desktop app): kubernetes → docker
• Operating system:

[mohamed3nan]

Hi @ypyly

I was able to replicate the error and found that you’re using an old legacy expression syntax: $node["Node Name"]

Please switch to the current standard syntax $("<node-name>").item which is working as expected:

• Data mapping in the expressions editor | n8n Docs

So in your case, for the Postgres Chat Memory key, try updating your syntax to:

{{ $('set_params').item.json.sessionId }}

Also, since other nodes in your workflow are still using the legacy syntax, I recommend updating those as well to avoid similar errors in the future.

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If you find this helpful, kindly mark the reply as the solution

[ypyly]

oh wow, I didn’t knew that I’ve been using an old legacy expression
Thanks for mentioning it. Works as expected.
P.S> yeah, went over all of my workflows removing usage obsolete way of referring nodes.