The /start API allows you to choose Signals for ID verification. Specify them in the /start signals parameter.

The following table describes each of the available signals.

Signal	Description
`address_validation`	Customer quality check for IP address validation.
`criminal_background`	Criminal background check.
`device_fingerprint`	Customer quality check for device fingerprint validation.
`document_liveness_idrnd`	Document probability checks for on-screen presentation, printed copy, and portrait substitution.
`email_validation`	Customer email address check.
`idcheck`	Barcode analysis on North American driver licenses, including real IDs, and extended IDs.
`kyc`	Watchlists background check. This provides watchlists and sanctions screening based on a tiered approach. See Sanctions Screening Tiers.
`ocr_match`	Compare OCR scan to barcode or MRZ data.
`ocr_scan`	OCR scan on passport books, passport cards, and other forms of identification.
`phone_validation`	Customer quality check for phone validation.
`selfie`	Facial matching and liveness.

Signal Selection

To selectively apply signals in the /start endpoint, you use the signals parameter in the request body. If you do not provide these parameters, all data for signals to which your company account is subscribed will be returned.

For example, the following /start private_data request body could be used to obtain watchlists (kyc) and (ocr_scan) results for a passport:

{  
  "private_data": {
    "document_type": "passport",
    "signals": [  
      "kyc",  
      "ocr_scan"  
    ],      
  }  
}

To additionally obtain the results of a criminal background check, (criminal_background), the /start private_data request body might look like this:

{  
  "private_data": {
    "document_type": "passport",
    "signals": [  
      "kyc",  
      "ocr_scan",
      "criminal_background"
    ],      
  }  
}