Call Flow

The Call Flow node triggers and executes another workflow. It supports passing parameters and receiving return values.

Overview

Save reusable sub-logic (such as login, data cleaning) as an independent workflow file and call it from the main workflow via this node. When called, it blocks and waits for the sub-workflow to finish executing, then continues downstream nodes after receiving the return value.

The called workflow must be started via Manual Execute or Signal Trigger — otherwise, it won't appear in the candidate list.

Usage

After dragging in the node, configure the following three items:

Target Workflow

Select the workflow to call from the dropdown. The dropdown automatically filters to workflows containing a "Manual Execute" or "Signal Trigger" node — only these two entry points can be called externally.

Carry Data

JSON parameters passed to the sub-workflow. The sub-workflow receives them via its trigger's "Receive Data" field.

Supports {{variableName}} references — variables are replaced with actual values before JSON parsing, so you can embed upstream variables anywhere in the JSON:

{
  "url": "{{targetUrl}}",
  "orderId": "{{orderId}}",
  "config": {
    "timeout": 5000,
    "retry": {{retryCount}}
  }
}

Assuming upstream retryCount = 3, the actual JSON passed to the sub-workflow is:

{
  "url": "https://shop.example.com/order/12345",
  "orderId": "12345",
  "config": {
    "timeout": 5000,
    "retry": 3
  }
}

Note: {{retryCount}} is not quoted, so it's replaced with the number 3. If written as "{{retryCount}}", it would be replaced with the string "3". Decide whether to quote based on the type the sub-workflow expects.

The data format is JSON, supporting relaxed syntax like trailing commas, single quotes, and comments.

Output Variable

The variable name to store the sub-workflow's return value. Data returned by the sub-workflow via the Return node is stored in this variable, available to downstream nodes in the main workflow via {{variableName.field}}.

Main workflow — referencing the return value after the call:

Assuming Output Variable is set to "result" and the sub-workflow returns:
{
  "status": "success",
  "amount": 99.00,
  "items": ["A", "B"]
}

Main workflow downstream references:
{{result.status}}   → "success"
{{result.amount}}   → 99.00
{{result.items}}    → ["A", "B"]

Complete Example

Sub-workflow (the called side):

1. Entry is "Manual Execute" with Receive Data set to data
2. The sub-workflow accesses the main workflow's parameters via {{data.url}}, {{data.orderId}}
3. After execution, the Return node returns the result:

{
  "status": "success",
  "amount": "99.00"
}

Main workflow (the calling side):

1. "Call Flow" node: Target Workflow set to the sub-workflow, Carry Data filled with JSON containing variables, Output Variable set to result
2. After the call completes, reference the return value via {{result.status}}, {{result.amount}}
3. If Output Variable is left empty, the return value is discarded and the sub-workflow only executes as a side effect

Parameter Reference

Parameter	Type	Default	Description
Target Workflow	Dropdown	—	Required. Only lists workflows containing Manual Execute or Signal Trigger
Carry Data	JSON	—	Parameters passed to the sub-workflow. Supports {{variableName}} references; variables are replaced before JSON parsing
Output Variable	Text	—	Variable name to store the return value. Leave empty to discard

FAQ

Target workflow doesn't appear in the dropdown

Symptom: The target workflow has been saved, but doesn't show in the dropdown.

Cause: The target workflow is missing a Manual Execute or Signal Trigger node.

Solution: Add a "Manual Execute" or "Signal Trigger" node to the target workflow and save it.

Sub-workflow doesn't receive the passed parameters

Symptom: JSON was filled in Carry Data, but the sub-workflow's variables are empty.

Cause: The sub-workflow trigger's "Receive Data" field is empty, or the field name doesn't match the variable name referenced inside the sub-workflow.

Solution: Confirm the sub-workflow trigger's "Receive Data" is filled in (e.g., data), and the sub-workflow references it via {{data.fieldName}}.