Accumulation Head¶
Returns the first element (head) from an Accumulation. If the accumulation is empty or invalid, it outputs None. The node preserves the original item type (it is type-agnostic).
Usage¶
Use this node when you need to extract the first item from a growing collection of values built with Accumulation-compatible nodes. Commonly paired with Accumulate (to build the list) and Tail (to get the remainder), it helps in stepwise or iterative processing where you need the current first element.
Inputs¶
| Field | Required | Type | Description | Example |
|---|---|---|---|---|
| accumulation | True | ACCUMULATION | An Accumulation object produced by nodes like Accumulate or List to Accumulation. Represents an ordered collection of items. |
Outputs¶
| Field | Type | Description | Example |
|---|---|---|---|
| head | WILDCARD | The first item in the accumulation. Returns None if the accumulation is empty or invalid. | hello |
Important Notes¶
- Type-preserving output: The output item retains its original type (text, number, image reference, etc.).
- Empty handling: If the accumulation has no items, the output is None.
- Input expectations: This node expects a valid Accumulation object. Provide data from Accumulate or List to Accumulation nodes.
- Order-sensitive: The node returns the earliest added item (index 0) in the accumulation.
- Safety behavior: On errors or malformed input, the node returns None.
Troubleshooting¶
- Output is None: Ensure the accumulation is not empty and is created by Accumulate or List to Accumulation. Verify that at least one item has been added.
- Unexpected type at output: The node returns the original item type. Confirm you are handling the correct type downstream.
- Node appears to do nothing: Confirm the upstream node actually outputs an ACCUMULATION type, not a plain list. If you have a list, convert it using List to Accumulation.
- Order mismatch: The node always returns the first element. If you need a different item, use Accumulation Get Item or process with Tail to access subsequent elements.