> ## Documentation Index
> Fetch the complete documentation index at: https://docs.subverseai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Human in the loop

# Human in the Loop

The **Human in the Loop** node pauses an orchestration run and sends an approval request to a human via Slack or email. Execution resumes only after the reviewer approves or rejects the request — or after a configured timeout.

<img src="https://mintcdn.com/subverse-611dde60/UZLalX8VX2i72yfQ/images/agentverse/human-in-the-loop-logic-node.png?fit=max&auto=format&n=UZLalX8VX2i72yfQ&q=85&s=fc50c7b9a3df0c81620e545995550a2d" alt="Human In The Loop Node" width="800" height="1360" data-path="images/agentverse/human-in-the-loop-logic-node.png" />

***

## Use Cases

* Require manager approval before processing a large transaction
* Route AI-generated content for human review before publishing
* Create an approval step in a multi-stage data pipeline
* Escalate flagged support tickets to a human agent

***

## Node Reference

### Parameters

| Parameter            | Type   | Required | Description                                          |
| -------------------- | ------ | -------- | ---------------------------------------------------- |
| **Approval Channel** | Select | Yes      | How to send the approval request: `Slack` or `Email` |

### Email Channel Parameters

| Parameter           | Type   | Required | Description                                                                                      |
| ------------------- | ------ | -------- | ------------------------------------------------------------------------------------------------ |
| **Email Addresses** | String | Yes      | One or more approver email addresses, separated by commas                                        |
| **Subject**         | String | No       | Email subject line (default: `Workflow Approval Required`)                                       |
| **Message**         | String | No       | Body message for the approval email (default: `Please review and approve this workflow action.`) |

### Slack Channel Parameters

| Parameter            | Type       | Required    | Description                                               |
| -------------------- | ---------- | ----------- | --------------------------------------------------------- |
| **Slack Credential** | Credential | Yes         | Select or create a Slack OAuth2 credential                |
| **Send To**          | Select     | Yes         | `Channel` or `User`                                       |
| **Slack Channel**    | String     | Conditional | Channel name or ID (required when `Send To` is `Channel`) |
| **Slack User**       | String     | Conditional | User ID or email (required when `Send To` is `User`)      |
| **Message**          | String     | No          | Custom message to include in the approval request         |

### Timeout Settings

| Parameter      | Type   | Required | Description                                                         |
| -------------- | ------ | -------- | ------------------------------------------------------------------- |
| **Value**      | Number | Yes      | How long to wait for a response before timing out (default: `24`)   |
| **Unit**       | Select | Yes      | Unit for the timeout: `Minutes`, `Hours`, `Days` (default: `Hours`) |
| **On Timeout** | Select | Yes      | What to do if no response is received: `Approve` or `Reject`        |

***

## How It Works

1. The node sends an approval request to the configured channel (Slack or email).
2. The request includes **Approve** and **Reject** action buttons.
3. The orchestration run is paused and waits for a response.
4. When the approver clicks **Approve** or **Reject**, execution resumes on the corresponding branch.
5. If no response arrives within the timeout window, the **Default Action** is applied.

***

## Output Branches

The node has two output branches:

| Branch       | Condition                                                                |
| ------------ | ------------------------------------------------------------------------ |
| **Approved** | The approver clicked Approve, or timed out with Default Action = Approve |
| **Rejected** | The approver clicked Reject, or timed out with Default Action = Reject   |

Connect different downstream nodes to each branch to handle both outcomes.

***

## Output Data

The output includes the original upstream data plus the reviewer's decision:

```json theme={null}
{
  "decision": "approved",
  "reviewer": "alice@example.com",
  "reviewedAt": "2025-03-10T09:15:00.000Z",
  "comment": "Looks good, proceed."
}
```

Reference in downstream nodes:

```
{{ humanInTheLoop.decision }}
{{ humanInTheLoop.reviewer }}
{{ humanInTheLoop.comment }}
```

***

## Related Nodes

* [Wait](./wait.md) — A lower-level pause node for custom webhook-based resume flows
* [Conditions](./conditions.md) — Branch based on the approval outcome
* [Slack](./slack.md) — Send a follow-up Slack message after the decision