API reference. MySign Developer Centre

Endpoint

Create envelope.

POST /native/envelopes/create

Creates a new signing envelope from a document template with merge data and signatory details.

Headers

Header	Value
Authorization	Bearer YOUR_API_TOKEN
Content-Type	application/json
Accept	application/json

Request body parameters

Parameter	Type	Required	Description
template_id	string (ULID)	Required	The ULID of the document template to use
merge_data	object	Required	Key-value pairs matching your template merge tags
signatory	object	Required	Signatory information (name, email, phone)
signatory.name	string	Required	Full name of the person who will sign
signatory.email	string (email)	Required	Email address of the signatory
signatory.phone	string	Optional	Phone number of the signatory
expires_in_days	integer	Optional	Days until envelope expires (default: 30)

Request example

cURL

curl -X POST https://api.mysign.co.uk/api/v1/native/envelopes/create \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "template_id": "01ABCDEFGHIJKLMNOPQRSTUVWX",
    "merge_data": {
      "COMPANY_NAME": "Acme Corporation Ltd",
      "CONTRACT_DATE": "2025-11-16",
      "CONTRACT_ID": "ACM-2025-001",
      "AMOUNT": "£10,000"
    },
    "signatory": {
      "name": "John Doe",
      "email": "[email protected]",
      "phone": "+44 7700 900000"
    },
    "expires_in_days": 30
  }'

Response

Success response (200)

JSON

{
  "success": true,
  "data": {
    "envelope_id": "01ABCD...",
    "signing_url": "https://acme.mysign.co.uk/...",
    "status": "ready",
    "created_at": "2025-11-16T14:30:00Z",
    "expires_at": "2025-12-16T14:30:00Z"
  }
}

Response fields

envelope_id Unique ULID for the envelope

signing_url URL to send to the signatory

status Current envelope status

created_at ISO 8601 timestamp

expires_at Expiration timestamp

Lifecycle

Envelope status values.

draft

Envelope created but not sent

ready

Ready to be sent to signatory

sent

Sent to signatory but not yet viewed

in_progress

Signatory is viewing/signing

completed

All signatures collected

voided

Manually cancelled

expired

Reached expiration date

API reference.