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Overview

Cardinal can automatically detect signatures within documents. For each detected signature, you’ll receive:
  • signature_url – a cropped image of the detected signature.
  • is_signature – whether the region is confirmed to be a signature ("yes" or "no").
  • signed_by – signer name.
Example of signature metadata returned by the API Example: Detected signatures and accompanying metadata

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How to Enable

To enable signature detection, set signatureDetect: true in your API request.
  • Default: signatureDetect = false
  • To enable signature detection, set signatureDetect = true.
  • ⚠️ Enabling signature detection will add latency to your requests, since additional detection passes are run.

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Example Response

{
  "signatures": [
    {
      "is_signature": "yes",
      "signed_by": "Dr. John Doe",
      "signature_url": ""
    }
  ]
}
This enables use cases like:
  • Verifying the presence of required signatures.
  • Identifying who signed a document.
  • Automating compliance workflows that require signature verification.
Signature detection is included in the JSON output alongside other extracted elements such as tables, barcodes, and figures.