E-Signature API

Your first signature request, live in 5 minutes.

One POST sends a document and returns a signing link. Webhooks tell you when it's signed. No envelopes, no per-document fees.

10 docs/month free · webhooks + embed included · no credit card

POST /api/v1/documents/:id/send
curl -X POST https://www.sigpen.com/api/v1/documents/doc_nda/send \
  -H "Authorization: Bearer sp_test_your_key" \
  -H "Content-Type: application/json" \
  -d '{
    "signers": [{
      "email": "alice@acme.com",
      "name":  "Alice Chen",
      "fields": [{ "type": "signature",
        "page": 1, "x": 72, "y": 640,
        "width": 180, "height": 48 }]
    }]
  }'
200 · RESPONSE
{ "status": "sent", "signers": [{ "status": "pending" }] }

Embedded signing

Signing that lives inside your product.

A few lines of code put the signer in your app. Try the flow below, then run the real thing against the API in the sandbox.

embed.js
<script src="https://www.sigpen.com/embed.js"></script>

// signUrl from POST /api/v1/documents/:id/embedded-sign-url
SigPen.open({
  signUrl: signUrl,
  container: '#signing-container',
  onSign:  () => celebrate(),
  onClose: () => refreshStatus(),
})

The one canonical recipe: POST /documents/:id/embedded-sign-url returns a short-lived signUrl; SigPen.open renders it and wires onReady/onSign/onDecline/onError callbacks. Docs →

INTERACTIVE PREVIEW
yourapp.com — embedded signer

Consulting Agreement (Sample)

1 of 1 required

This card is a preview. Run the real embed in the sandbox → (free developer account)

All plans

Documents API

Upload, send, track, and download, with inline field placement per signer. No visual editor required.

Read docs →
All plans

Webhooks

8 events, HMAC-signed, 7 retries over 24 hours. Verify your handler with a one-call test event.

Read docs →
All plans

Embedded signing

embed.js drops the signer into your app. One canonical recipe, callbacks for every outcome.

Read docs →
Business

Forms prefill

70+ legal and government forms, prefilled via API and sent for signature in one call.

Read docs →

Pricing

Gate scale, not capability.

The sandbox exercises everything: webhooks, embedded signing, the full API. Pay when you go to production volume.

Developer (sandbox)ProfessionalBusiness
PriceFree$29/mo$49/mo
Documents / month10UnlimitedUnlimited
Test modeUnlimitedUnlimitedUnlimited
Webhooks✓ 3 endpoints✓ 20✓ 20
Embedded signing
Rate limit10 req/min30 req/min100 req/min
Bulk send25 recipients100 recipients
Forms library API

After signup

Three steps to your first signature.

Everything happens in the developer dashboard: keys, request logs, webhook test events.

1

Create a test key

Mint an sp_test_ key in the dashboard. Test mode is unlimited and never counts toward quota.

2

Send your first document

Upload a PDF and send it with one POST. Watch it land in the request log.

3

Receive a webhook

Register an endpoint, then fire a signed test.webhook event at it with one call.

Ship signatures this afternoon.

Free sandbox · webhooks + embed included · production from $29/mo

Get a free sandbox key