WaiverSign API: Creating a Signing Session

To send participants to a WaiverSign signing page, create a signing session by sending a POST request to the API. The response includes a unique URL you redirect the participant to. Any participant information you include in the request will pre-populate the signing form, reducing manual entry for your signers.

Endpoint

POST https://app.waiversign.com/ws/api/session

Send your request body as JSON with the Content-Type: application/json header. No authentication is required.

Request Parameters

Person Object

Each entry in personInfoList represents one participant. Apart from isAdult, all fields are optional and are used for pre-population only. The signer can edit any pre-filled values on the signing page.

State example:

{"name": "Utah", "abbreviation": "UT"}

Phone Object

Each entry in a Person's phoneList represents one phone number. All fields are optional.

Identification Object

Used within a Person's identification field.

Custom Fields

The customFieldList array lets you pre-populate custom fields that are configured on your waiver document. Each entry needs a name and a value:

"customFieldList": [
  {"name": "Medications", "value": "Yes"},
  {"name": "Emergency Contact", "value": "Lisa Turner (888-888-8888)"}
]

For checkbox-type fields, pass selected options as a comma-separated string:

{"name": "Sandwich Toppings", "value": "Ham,Lettuce,Tomato,Mayo"}

Example Request

This example creates a session for one adult and one minor to sign a single document. The adult's information will be pre-filled on the form.

{
  "documentIdList": ["5afba2484fa1da256ed15c7c"],
  "personInfoList": [
    {
      "isAdult": true,
      "firstName": "Tim",
      "lastName": "Turner",
      "email": "tim@example.com",
      "birthDate": "01/01/2001",
      "streetAddress": "1234 Main",
      "city": "Sandy",
      "state": {"name": "Utah", "abbreviation": "UT"},
      "country": "USA",
      "postalCode": "84111",
      "phoneList": [
        {
          "phoneType": "Mobile",
          "phoneNumber": "+8012342232",
          "dialCode": "+1",
          "formattedPhoneNumber": "801-234-2232"
        }
      ],
      "customFieldList": [
        {"name": "Emergency Contact", "value": "Lisa Turner (888-888-8888)"}
      ]
    },
    {
      "isAdult": false,
      "firstName": "Lilly",
      "lastName": "Turner",
      "birthDate": "04/02/2017"
    }
  ],
  "referenceId": "booking-12345",
  "returnUrl": "https://www.yoursite.com/thank-you",
  "callbackUrl": "https://www.yoursite.com/api/waiver-callback",
  "expiresAt": "2025-12-31"
}

Response

A successful request returns a JSON object with a signing URL:

{
  "success": true,
  "payload": {
    "url": "https://app.waiversign.com/session/5ab4092d78553d5b33af4f54"
  }
}

Redirect the participant to the returned URL to begin the signing process.

Error Responses

If a request is invalid, the API returns a 400 status code with a JSON object describing the problem:

{
  "code": 400,
  "message": "The 'personInfoList' field is invalid. It should contain at least one object with at least 'isAdult' property set",
  "success": false
}

Common errors include:

• Missing personInfoList: "The 'personInfoList' field is invalid. It should contain at least one object with at least 'isAdult' property set"
• Missing documentIdList: "The documentIdList field is required and must be an array."
• Invalid document ID: "The documentIdList field has the following invalid ids: [your_invalid_id]"

Things to Know

• Both documentIdList and personInfoList are required. Every session needs at least one document ID and at least one person with isAdult set to true.
• One adult per session. Exactly one person in personInfoList should have isAdult: true. You can include multiple minors (isAdult: false) alongside them.
• Sessions expire. If you don't set expiresAt, the session automatically expires 24 hours after creation. Once expired, the signing URL shows a "cannot find signed session" message and will no longer load.
• Pre-populated data is editable. Participants can change any values that were pre-filled through the API.

Updated on: 06/24/2026