Business applications can use this service API to sign a document (both electronic and digital) without displaying the document to the end user using SigningHub.  For example, a business application may have another method to display the document to the user, and only the signing functionality of SigningHub is required, or for bulk operations it may be justified to sign without requiring the user to view and approve every document individually.  If there are changes to be saved in the document before signing, Fill Form Fields API should be called before calling the Sign Document API.  Note any mandatory input fields on a document require completing before this API will successfully complete.

The signatory is identified by the access token presented in the call.  Therefore, authentication of the signatory is required prior to making this call.  You cannot authenticate as an Enterprise Admin with the scope variable, and sign a document on behalf of a user.  The access token must be issued to the signatory as a result of direct authentication.

When this call completes it is important that if the signatory was the last signer for a document that the Finish Document API call is invoked.  The reason is because without calling that API the document will remain in a status of "In Progress" to the document owner.  Once the API has been called, the status will change to "Completed" for the document owner.

Once document is signed, the verification response can be seen from Get Document Verification API.

First or Second Factor OTP Usage for Authentication

If OTP authentication is turned on for the server side signing operation, client applications will need to generate a OTP for the mobile number using Signer Authentication via OTP API call.  Respective business applications must retrieve the OTP from the use and submit it when making the API call.  This is done using the "x-otp" header in the request. 

https://api.signinghub.com/v3/packages/{package_id}/documents/{document_id}/sign
HTTP Verb		POST
Content-Type		application/json
Accept		application/json
Authorization		Bearer {access_token}
x-otp (optional)		'456789'
Request Body		{    "field_name": "signinghub_signature_field_name",    "hand_signature_image": "base64",    "signing_reason": "Witness Signature Reason",    "signing_location": "Lahore",    "contact_information": "00923331234567",    "user_name": "John Doe",    "user_password": "Password123!",    "appearance_design": "HAND_SIGNATURE",    "signing_capacity": "Certification Profile 1",    "witness_signing_capacity": "Signing Profile 1",     "skip_verification": "false"  }
Status Code	Message	Response Body
200	OK	{    "field_name": "signinghub_signature_field_name",     "status": "SIGNED"        "verification": {       "field_name": "signinghub_signature_field_name",       "signer_name": "John",       "signer_photo": "base64",       "signature_status": "valid",       "signing_reason": "Witness Signature Reason",       "signing_location": "Pakistan",       "contact_information": "7544323243",       "signing_time": "2015-09-08T07:29:33",       "ltv": true,       "qualified": false,       "certified": false,       "certify_permission": "NO_CHANGES_ALLOWED",       "timestamp_at": "2015-09-08T07:29:35",       "timestamp_authority": "Ascertia",       "subject_dn": "CN=John",       "issuer_dn": "O=Ascertia,CN=Ascertia Docs CA 1",       "cert_valid_from": "2015-09-08T07:29:33",       "cert_valid_to": "2015-09-08T07:29:33",       "signature_type": "PADES_PART2",       "signature_algorithm": "SHA256",         "signed_hash": "8RmV1Ulb9w+0T+gq8z3HUP8dYzDuLzBLe5CDFDrVnoA=",       "signature_application": "Ascertia",       "signature_policy_id": 0,       "signature_policy_uri": null         "error_message": null    } }
401	Unauthorized	{   "Message": "Request authorization denied" }
		{   "Message": "User authentication required" }
403	Forbidden	{   "Message": "Document does not belong to user" }
		{   "Message": "Invalid Signature appearance name" }
		{  "Message": "You cannot access this document after the access period ends" }
		{   "Message": "Account is disabled" }
		{  "Message": "You are not allowed to perform the requested operation" }
		{   "Message": "Your signatures limit has been reached" }
		{   "Message": "Could not upload file  -  it is infected by malware" }
404	Not Found	{   "Message": "Document not found" }
500	Internal Server Error	{   "Message": "An internal server error occurred while processing the request" }