> For the complete documentation index, see [llms.txt](https://doc.duaer.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.duaer.com/integrations/builtin/core-nodes/n8n-nodes-base.functionitem.md).

# Use Function Item in Duaer

Function Item in Duaer is a built-in core node for data or flow control without an external SaaS account. Node note: Run custom function code which gets executed once per item
## Function Item in Duaer

Function Item is a built-in core node in Duaer for data or flow control. It usually does not need an external SaaS credential.

The product’s node note is: Run custom function code which gets executed once per item.

## Credentials and parameters

Most core nodes do not need an external credential. If the node still asks for one, create it from the fields it shows.

Parameters accept expressions. Tool parameters that an AI Agent should fill use $fromAI. When a run fails, read the error on the node output first.
## Questions

### How do you add Function Item to a Duaer digital organization?

Open the node panel on the Duaer canvas, search for Function Item, and drop it onto the digital organization. Connect it after a trigger or a previous node.

### What should you check first when Function Item fails in Duaer?

Read the error text on that node’s output, then confirm the credential still works and required parameters are filled. For app nodes, also check permissions and quota on the provider side.