Free Support Forum -

How to add Signature Field in PDF Document and Certify PDF document with Aspose.PDF REST API

Am I correct in assuming that you can’t create FieldType.SignatureField though the Aspose.PDF Cloud API? If I’m wrong can someone direct me to an example please?

I also can’t see an option for certifying a PDF with a digital certificate.


Thanks for your inquiry, you need to create Text Field type as following for signature field.

curl -X POST "" 
-H "accept: application/json" 
-H "authorization: Bearer [JWT_Access_Token]" 
-H "Content-Type: application/json" -d "{ \"Name\": \"signature1\", \"Type\": \"Text\", \"Rect\": { \"LLX\": 50, \"LLY\": 200, \"URX\": 150, \"URY\": 220 }, \"Values\": [ \"\" ]}"

I am looking into the requirement and will update you shortly.

Thanks for your reply, this creates a field but when I try to sign it I get the following error:

{“error”:{“code”:“error”,“message”:“The name ‘SignatureField1’ doesn’t represent valid signature field or signature field is not empty.”,“description”:“Operation Failed.”,“innerError”:{“requestId”:null,“date”:“2019-08-08T08:25:35.5620226Z”}}}


Thanks for your inquiry. We can add signature using PostSignPage API. However, we have revisited the existing feature and planned to add SignatureField support and certify PDF document in Aspose.PDF Cloud. We have logged following tickets in our issue tracking system for new features. We will notify you as soon as these are implemented.

PDFCLOUD-1182: Add SignatureField support
PDFCLOUD-1183: Certify PDF document

@tilal.ahmad thanks for your support. Your suggestion of using the PostSignPage API produces no error. The signature is still not visible in the document though. I can tell it’s been added as the document is larger, it’s just not visible. Am I missing a parameter from the SignPage method?

Thanks for your feedback. Yes, the Text field is not working as expected with the signature. So we have planned(PDFCLOUD-1182) to add SignatureField in Aspose.PDF Cloud for signing feature. Please wait for the resolution of the ticket for signing the PDF document.


Thanks for your patience. We have good news for you, your reported issue PDFCLOUD-1183 has been resolved. You can use Certify API to Certify PDF document.


Please note your above reported issue PDFCLOUD-1182 is resolved. Now you can use PostSignatureField API method to add signature field in the PDF document.