Human in the Loop
Pause workflow execution for human review and feedback before continuing
What does this node do?
The Human in the Loop node pauses workflow execution and presents content to a human reviewer for approval before continuing. This lets you add manual checkpoints at critical points in your workflow — review AI-generated content, validate data, or approve actions before they execute.
Common uses:
- Review AI-generated content before publishing to a CMS
- Validate data before writing to external systems
- Quality check email content before sending
- Approve changes before updating a CRM or database
Quick setup
Add the Human in the Loop node
Find it in Tools → Human in the Loop
Connect the input
Connect the content port to the data you want reviewed (e.g., the output of an LLM node)
Set a custom message (optional)
Write a message that tells the reviewer what to check or approve
Connect the output
Connect the output to the next node — execution resumes once the reviewer approves
Configuration
Input
content string required The content to present to the reviewer. Accepts any type — strings, objects, arrays, etc. This is the data that the human will review before the workflow continues.
Optional fields
custom_message string A custom message displayed to the reviewer. Use this to provide context about what to review, what to look for, or what criteria to apply.
Examples:
- “Review this blog post for accuracy and tone before publishing”
- “Verify the extracted data matches the source document”
- “Approve this email before it is sent to the client”
Output
The node outputs the reviewed content as a string. Once the reviewer approves, the content passes through to the next node.
{
"output": "The reviewed and approved content from the human reviewer"
}Examples
Review LLM output before writing to Notion
Ensure AI-generated content meets quality standards before publishing:
Workflow:
- Web Scraper — Fetch source data
- LLM — Generate a summary or article
- Human in the Loop — Custom message: “Review this article for accuracy, tone, and completeness before it is published to Notion”
- Notion Database Writer — Publish the approved content
Approve email content before sending
Add a manual approval step before sending automated emails:
Workflow:
- LLM — Generate a personalized email based on customer data
- Human in the Loop — Custom message: “Review this email for the correct customer name, offer details, and professional tone before sending”
- Email Sender — Send the approved email
Best practices
- Use clear custom messages. Tell the reviewer exactly what to check. A message like “Review for accuracy” is better than no message, but “Check that all product prices match the source spreadsheet” is even better.
- Place nodes strategically. Put Human in the Loop before any irreversible action — sending emails, writing to databases, publishing content, or updating external systems.
- Keep the review scope focused. If a workflow produces multiple outputs that need review, consider using separate Human in the Loop nodes for each so reviewers can approve them independently.
Common issues
The workflow seems stuck and won't continue
Cause: The workflow is waiting for human approval. This is expected behavior — the workflow pauses until a reviewer approves the content.
Solution: Check the workflow execution panel for pending review requests. The reviewer needs to open the review, check the content, and approve it for the workflow to continue.
Content is not passed through to the next node
Cause: The content input may not be connected, or the upstream node produced an empty output.
Solution: Verify the content input port is connected to the correct upstream node. Check that the upstream node executed successfully and produced output. Test the upstream node independently to confirm it generates data.