JSON object null from child to parent workflow

MindStudio General
1

I’m building a customer support agent in MindStudio with three workflows:

  • main.flow – Reads unread Gmail messages using the Gmail integration.
  • evaluate.flow – Processes each email, classifies it into a topic, and invokes a child workflow.
  • content.flow – Retrieves information from a knowledge source based on the topic and returns a structured JSON response.

The main.flow and content.flow work correctly. The issue occurs when content.flow returns its output to evaluate.flow.

Child workflow (content.flow)

The Terminator returns:



{
  "testOutput": {
    "query": "How do I request a refund?",
    "response": "Thank you for reaching out! To request a refund..."
  }
}

Parent workflow (evaluate.flow)

The Run Workflow block maps:



testOutput  -->  summary[]

where summary is the output variable configured in the Run Workflow block.

However, the parent receives:



{
  "summary": [
    null
  ]
}

instead of:



{
  "summary": [
    {
      "query": "How do I request a refund?",
      "response": "Thank you for reaching out! To request a refund..."
    }
  ]
}

Troubleshooting performed

I verified that:

  • :white_check_mark: The child workflow executes successfully.
  • :white_check_mark: The child workflow returns the expected JSON in its execution logs.
  • :white_check_mark: Even replacing the output with a simple string ("test123") still resulted in summary = [null].
  • :white_check_mark: The Terminator is configured correctly with the JSON output.
  • :white_check_mark: The Run Workflow block maps testOutput to summary[].
2

Hi @learningAI,

Thanks for the detailed post!

Could you share a remix link to your agent? That will let me copy it and look into this further. Here’s how:

  1. Publish the agent
  2. Click the agent’s name at the top left of the editor
  3. Go to the Remixing tab
  4. Enable remixing and copy the link
    image
    image1342×505 73.3 KB
3

https://app.mindstudio.ai/agents/customer-support-agent-643a09f7/remix

Please review the remixed agent link. Your advise will be helpful. I have spent hours trying to resolve the issue.

4

Hi @learningAI,

From what I can see, you’ve got Breakpoints enabled on the Router and Generate Text blocks in Content.flow. Breakpoints only pause a run when you’re using the Preview Draft option and running a regular workflow. Since Content.flow runs via a Run Workflow block, the generated values aren’t getting surfaced.

Can you right-click those blocks and disable the breakpoints? That should fix it.

You can also learn more about the breakpoints here:

5

Hi Alex, thank you so much! it solved the issue. I really appreciate your help.