API

Built for the integration.

REST + JSON over HTTPS, OAuth2 authorization, webhooks for every state transition. Designed to be the signing layer underneath your CRM, not a separate destination.

Quick overview

The API mirrors the product: every concept maps to a resource you can read, create, or subscribe to. Authentication is OAuth2 — no long-lived static tokens. The reference implementation is VG Realestate, which uses the same endpoints documented here.

Base URL

https://api.vg-sign.com/v1

Authentication

OAuth2 authorization-code flow. Register an app, redirect users to /oauth/authorize, exchange the callback code for an access token, and call the API with Authorization: Bearer …. Tokens scoped per app and per user.

Core endpoints

  • POST /envelopes — create a new envelope from one or more PDFs.
  • POST /envelopes/:id/recipients — add signers, configure roles and signing order.
  • POST /envelopes/:id/fields — place signature, initial, date, and text fields by JSON or template.
  • POST /envelopes/:id/send — fire signing emails / SMS to recipients.
  • GET /envelopes/:id — read envelope state, signed PDF URLs, and audit trail.
  • POST /webhooks — register endpoints for envelope lifecycle events.

Webhook events

Every state change emits a webhook with a signed payload. Events: envelope.sent, envelope.viewed, envelope.signed, envelope.completed, envelope.declined, envelope.voided.

Payloads are HMAC-SHA256 signed with your shared secret. Verify before processing — see the security conventions on the Security page.

SDKs

Official SDKs ship with type-safe clients for the core flows. Available:

  • TypeScript / Node — npm i @vg-sign/sdk
  • Python — pip install vg-sign
  • Go — go get github.com/vg-sign/go-sdk

SDK availability tracks GA. If you need early access, write to hello@vg-sign.com.

Rate limits

Free tier: 60 req/min, 1k webhooks/day. Pro tier: 600 req/min, 10k webhooks/month included. Enterprise tiers are uncapped — contact us.

Reference

Full reference docs (every endpoint, every field, every error code) are being assembled. In the meantime, ask support@vg-sign.com for the staging Postman collection or an OpenAPI spec.