API Overview

The VisiSign API is a REST API that uses JSON for request and response bodies. All endpoints require authentication via API key.

Base URL

https://api.visisign.app/v1

Authentication

Include your API key as a Bearer token in the Authorization header:

Authorization: Bearer vsk_your_key_here

See Authentication for details on key management.

Content types

• JSON requests: Set Content-Type: application/json
• File uploads: Use multipart/form-data
• Responses: Always application/json

ID prefixes

Resources use prefixed IDs for clarity:

Prefix	Resource
sr_	Signature request
sig_	Signer
tmpl_	Template

Pagination

List endpoints return paginated results:

{
  "signature_requests": [...],
  "pagination": {
    "page": 1,
    "per_page": 20,
    "total_pages": 5,
    "total_count": 100
  }
}

Parameter	Type	Default	Max	Description
page	integer	1	—	Page number
per_page	integer	20	100	Results per page

Form data

When fields have a mapping_key, VisiSign extracts the signer-entered values into the form_data object on the signature request. This is available on completed requests and in signature_request.completed webhook payloads.

{
  "form_data": {
    "taxpayer_name": "Jane Smith",
    "tin": "123-45-6789"
  }
}

Fields without a mapping_key are not included. See Webhooks for details.

Timestamps

All timestamps are ISO 8601 strings in UTC:

2026-03-04T12:00:00Z

Rate limits

The API enforces several rate limits to prevent abuse. If you exceed any limit, you’ll receive a 429 Too Many Requests response. Back off and retry after a short delay.

Limit	Threshold	Reset
Hourly sends	50 envelopes per hour	Rolling 1-hour window
Daily sends (API plan)	1,000 envelopes per day	Rolling 24-hour window
Daily sends (Individual plan)	50 envelopes per day	Rolling 24-hour window
Daily sends (Team plan)	Unlimited	—
Per-recipient	5 requests per hour to the same email	Rolling 1-hour window
API calls (Individual plan)	100 calls per month	Monthly reset
API calls (Team plan)	1,000 calls per month	Monthly reset
API calls (API plan)	Unlimited	—

New accounts (less than 30 days old) are limited to 10 signers per document. After 30 days, the limit increases to 50 signers per document.

Higher limits are available on request — contact support.

Errors

All error responses follow a consistent format:

{
  "error": {
    "type": "not_found",
    "message": "Signature request not found."
  }
}

See Errors for the full list of error types.