Custom Nested Workflows: The CustomWorkflow Node

Custom Nested Workflows: The CustomWorkflow Node

The CustomWorkflow Node allows you to execute an entire, separate workflow from within the current workflow. This is incredibly powerful for encapsulating reusable logic, breaking down complex processes into smaller, manageable parts, and orchestrating multi-step agentic tasks. The final result of the child workflow is captured and stored in the parent's state, accessible to subsequent nodes.

How It Works

A child workflow runs in an isolated context. It cannot directly access the outputs of the parent workflow (e.g., {agent1Output} from the parent is unavailable inside the child). Data must be passed in explicitly. The final result of the child workflow is then returned to the parent and saved as the output of the CustomWorkflow node itself.

Properties

Data Flow

Passing Data to a Child Workflow (Input)

1. scoped_variables (Recommended Method): This is the most powerful and flexible method. The values you list are passed to the child workflow and can be accessed at any node using the {agent#Input} syntax, where the number corresponds to the order in the array (e.g., the first item becomes {agent1Input}).

   • Parent Node Config:

     "scoped_variables": [
       "{agent1Output}",          // Becomes {agent1Input} in child
       "{lastUserMessage}"        // Becomes {agent2Input} in child
     ]
     

   • Usage anywhere in the Child Workflow's JSON:

     "prompt": "Analyze this text: '{agent1Input}'. The user's original question was '{agent2Input}'."
     

2. Prompt Overrides (Legacy Method): You can embed parent variables directly into the firstNode...PromptOverride properties. This method is limited as the data is only available to the first node of the child workflow.

Receiving Data from a Child Workflow (Output)

The process is simple: The entire final output of the child workflow is treated as the output of the CustomWorkflow node itself. For example, if a CustomWorkflow is the 4th node in your parent workflow, its result will be stored in the parent's {agent4Output} variable.

Full Syntax Example

This example from a larger research workflow demonstrates calling a reusable child workflow to search Wikipedia and summarize the findings.

{
  "title": "Custom Wiki Search 1: Initial Search",
  "type": "CustomWorkflow",
  "workflowName": "Util_Workflow_Wiki_Search_And_Summarize",
  "workflowUserFolderOverride": "_common",
  "is_responder": false,
  "scoped_variables": [
    "{agent1Output}",
    "{agent3Output}"
  ]
}

• workflowName: Executes the specified summarization workflow.
• workflowUserFolderOverride: Loads it from the shared _common folder.
• is_responder: false: The result (the summary from Wikipedia) will be captured in the {agent4Output} variable, not sent to the user directly.
• scoped_variables: Passes the output from the parent's first node ({agent1Output}) and third node ( {agent3Output}) into the child workflow, where they will be available as {agent1Input} and {agent2Input}, respectively.