Aggregate

Overview

The Aggregate node collects values from multiple upstream branches and combines them into a single array or keyed object, emitting once all expected inputs have arrived. Use it after fan-out patterns — such as parallel AI model executions or multi-contender battle runs — when downstream nodes need a unified collection rather than individual values. The node waits for every connected input port to receive a value before emitting, acting as a synchronization barrier. If any upstream branch produces an error, the node routes that error to the dedicated error output without blocking the remaining collection.

Configuration

Field	Type	Required	Description
mode	enum (array, object)	Yes	Controls the output shape. array produces an ordered list of values; object produces a key-value map where each port name becomes a key.
keys	string[]	No	Explicit key names for each input port when mode is 'object'. Must match the number of connected inputs. Defaults to port names if omitted.
allowPartial	boolean	No	When true, emits with whatever values have arrived if any input port times out instead of routing to the error output. Defaults to false.
timeout	number	No	Maximum milliseconds to wait for all inputs before timing out. Applies per-execution. Defaults to the workflow-level execution timeout.

Inputs

Port	Type	Description
input_1, input_2, …	any	Dynamically numbered input ports (one per upstream branch). Each port receives a value from its branch; all connected ports must emit before the node proceeds.

Outputs

Port	Type	Description
output	array or keyed object	The aggregated collection. Shape is an ordered array when mode is array, or a string-keyed object map when mode is object.
error	error object	Emits if any upstream input delivers an error and allowPartial is false. Payload includes message, port, and cause from the failing input.

Example

{
  "nodeType": "aggregate",
  "config": {
    "mode": "object",
    "keys": [
      "gpt4o_result",
      "claude_result",
      "gemini_result"
    ],
    "allowPartial": false,
    "timeout": 15000
  }
}