Developer platform
API & Webhooks
Programmatic e-signatures on your WordPress site
Create documents, manage signers and receive real-time webhooks with HMAC verification — full control without moving files to a third-party envelope SaaS.
REST create/send · webhook events · HMAC verify
API-first signing that stays self-hosted
Everything you do in the admin UI is available programmatically — documents never have to leave your WordPress infrastructure.
Full REST API
Create documents, add signers, check status and download signed PDFs through RESTful endpoints.
Real-time webhooks
HTTP callbacks for viewed, signed, completed, declined and related lifecycle events.
HMAC security
Authenticate API traffic and verify webhook payloads with SHA-256 HMAC signatures.
How developers integrate
Issue credentials, call the API or subscribe to webhooks, then verify every payload before acting on it.
- 1
Generate API credentials
Create an API key and secret in WPsigner settings for HMAC-signed requests.
- 2
Create and send via REST
Create documents, attach signers, set order and send invitations programmatically.
- 3
Subscribe to webhooks
Register an HTTPS endpoint for document.created, .sent, .viewed, .signed, .completed, .declined and .expired.
- 4
Verify HMAC and act
Validate signatures, then download PDFs, update your CRM or kick off internal workflows.
WordPress hooks plus no-code bridges
Prefer PHP? Use native WordPress actions and filters. Prefer no-code? The same events power Zapier, Make, n8n and Pabbly Connect without writing an HTTP client.
- RESTful document and signer endpoints
- Lifecycle webhooks with JSON payloads
- HMAC-SHA256 request and webhook auth
- Native WordPress hooks and filters
- Zapier, Make, n8n and Pabbly bridges
Developer surface area
- Create documents via REST
- Manage signers and order
- Status and PDF download
- Webhook event catalog
- HMAC authentication
- WordPress actions/filters
- Zapier / Make connectivity
- n8n / Pabbly connectivity
Built for custom product and ops stacks
Embedded product flows
Your SaaS or portal creates WPsigner documents when a user hits a milestone.
Internal tools
Ops scripts send contracts and poll or webhook status into your ticketing system.
Compliance pipelines
On document.completed, archive the PDF and hash into your records system.
No-code teams
Skip custom code and wire the same events through Zapier, Make, n8n or Pabbly.
Frequently asked questions
What can I do with the WPsigner API?
Create documents, add signers, set signing order, send invitations, check status, download signed PDFs and manage templates — the same capabilities as the admin UI, over REST.
How are API requests authenticated?
WPsigner uses HMAC-SHA256. Each request includes a signature derived from your key and secret so traffic cannot be tampered with and credentials stay off the wire in plain form.
What webhook events are available?
document.created, document.sent, document.viewed, document.signed, document.completed, document.declined and document.expired. Each JSON payload is HMAC-signed for verification.
Can I use Zapier instead of the API?
Yes. Zapier, Make, n8n and Pabbly Connect cover visual automations — for example creating a signing request when a new Google Sheets row appears.
Where are documents stored when using the API?
On your WordPress server with WPsigner. The API and webhooks control and notify; they do not relocate primary files to a vendor cloud.
Are API and webhooks included in every plan?
REST API access, webhooks and HMAC support are included with WPsigner. Bring your own integration hosts (Zapier, Make, n8n, Pabbly) if you use them.
Build custom integrations
Full REST API, HMAC auth and webhooks — self-hosted e-signatures you can drive from code.
Stop paying per envelope
Choose an annual or lifetime license with unlimited documents and no per-envelope fees. Keep control of your data and signing workflows.