Tool Approval¶

Lango provides an approval workflow for sensitive tool executions. When an agent attempts to call a tool that requires approval, the execution is paused until a human approves or the request times out.

Approval Policies¶

The approvalPolicy setting determines which tools require human approval before execution:

Settings: lango settings → Security

{
  "security": {
    "interceptor": {
      "enabled": true,
      "approvalPolicy": "dangerous"
    }
  }
}

Sensitive Tools¶

When using approvalPolicy: configured, you must explicitly list which tools require approval:

Settings: lango settings → Security

{
  "security": {
    "interceptor": {
      "approvalPolicy": "configured",
      "sensitiveTools": [
        "exec",
        "browser",
        "filesystem",
        "wallet_send"
      ]
    }
  }
}

Exempt Tools¶

Tools listed in exemptTools are exempt from approval regardless of the active policy. This is useful when a broad policy like all is active but certain safe tools should always execute immediately:

Settings: lango settings → Security

{
  "security": {
    "interceptor": {
      "approvalPolicy": "all",
      "exemptTools": [
        "knowledge_search",
        "memory_recall"
      ]
    }
  }
}

Approval Timeout¶

The approvalTimeoutSec setting controls how long the system waits for human approval before the tool call is rejected:

Settings: lango settings → Security

{
  "security": {
    "interceptor": {
      "approvalTimeoutSec": 30
    }
  }
}

If the timeout expires without approval, the tool call is denied and the agent receives an error.

Notification Channel¶

Configure which messaging channel receives approval notifications. When a tool requires approval, a notification is sent to the specified channel with details about the pending tool call:

Settings: lango settings → Security

{
  "security": {
    "interceptor": {
      "notifyChannel": "telegram"
    }
  }
}

The notification includes:

• Tool name
• Input parameters (with secrets masked)
• Requesting session ID
• Approve/deny action buttons (channel-dependent)

Headless Auto-Approve¶

For CI/CD or automated deployments where no human is available to approve, enable headless auto-approve:

Settings: lango settings → Security

{
  "security": {
    "interceptor": {
      "headlessAutoApprove": true
    }
  }
}

Configuration Reference¶

Settings: lango settings → Security

{
  "security": {
    "interceptor": {
      "enabled": true,
      "approvalPolicy": "dangerous",
      "sensitiveTools": [
        "exec",
        "browser"
      ],
      "exemptTools": [
        "knowledge_search"
      ],
      "approvalTimeoutSec": 30,
      "notifyChannel": "telegram",
      "headlessAutoApprove": false
    }
  }
}