Zoho Writer Sign’s API doesn’t accept recipient_phonenumber and recipient_countrycode as top-level keys.
To enable Email + SMS delivery, the recipient details must be passed inside the verification_type object of each recipient.

signer_data = [ JSON Array of recipients ]

[
  {
    "recipient_1": "[email protected]",
    "recipient_name": "John",
    "action_type": "sign",              // approve | sign | view | in_person_sign
    "language": "en",
    "delivery_type": [
      {
        "type": "sms",                  // sms | whatsapp | email
        "countrycode": "+91",
        "phonenumber": "9876543210"
      }
    ],
    "private_notes": "Hey! Please sign this document"
  },
  {
    "recipient_2": "[email protected]",
    "recipient_name": "Jack",
    "action_type": "in_person_sign",
    "in_person_signer_info": {
      "email": "[email protected]",      // Optional, required only when verification_info.type = "email"
      "name": "Tommy"
    },
    "language": "en",
    "verification_info": {
      "type": "email"                   // email | sms | offline | whatsapp
    }
  }
]



Key Points

The top-level parameter name is always signer_data.

It must be a JSON Array ([ ... ]) of recipient objects.

recipient_1, recipient_2, … are the unique keys used to identify each signer.

action_type defines what the recipient does (sign, approve, view, in_person_sign).

delivery_type is an array of objects:

type: email, sms, or whatsapp

For SMS/WhatsApp → include countrycode and phonenumber.

verification_info controls how the signer is verified (email, sms, offline, whatsapp).

in_person_signer_info is required for in_person_sign action types.