Why does the AI Agent 'call n8n workflow' return only the first item instead of all items?

When using the “call n8n workflow” (tool workflow) node, it returns a single item by default. The sub-workflow is indeed returning an array of items internally, but it’s wrapped into one output item. That’s why only the first item appears when you try to use the results in the main workflow.

Here are a couple of considerations and possible solutions:

• Output Mode Configuration:
  Check if there is an option such as “Return All Items” or a similar setting in the node’s configuration. By default the tool returns the first item of the array. Setting it to return all items will let you use multiple items in downstream workflows.

• Flattening the Data:
  If the sub-workflow returns a single item whose JSON is an array, you might need to split or “flatten” the array into separate items using a “Split In Batches” or similar node before passing to the AI agent.

• Handling in the AI Agent:
  When using the result within your AI Agent, ensure you’re referencing the complete output and not just the first index. For example, if the output is stored in a field (e.g. data), you may need to use an expression that loops over or joins the items as required.

Essentially, it is possible to retrieve multiple items from a sub-workflow, but you must adjust the configuration so that the entire array is passed through rather than just the first item. Reviewing the settings on the “call n8n workflow” node and possibly adding a node to split the array will help manage multiple items within your AI Agent.