docusign-webhooks

DocuSign Webhooks

When to Use This Skill

• Setting up DocuSign Connect webhook handlers
• Debugging DocuSign HMAC signature verification failures
• Understanding DocuSign envelope and recipient event types and payloads
• Handling envelope-completed, recipient-completed, or other Connect events
• Verifying the X-DocuSign-Signature-1 header

Verification (core)

DocuSign Connect signs the raw request body with HMAC-SHA256 keyed on your Connect HMAC secret and sends the digest as base64 in X-DocuSign-Signature-1. When multiple HMAC keys are active it sends one header per key (X-DocuSign-Signature-1, X-DocuSign-Signature-2, … up to 100); only one needs to match. The x-authorization-digest header names the algorithm (HMACSHA256). This is not the Standard Webhooks spec. The event type lives in the JSON body's event field (e.g. envelope-completed), not in a header.

Node:

const crypto = require('crypto');

// Collect every X-DocuSign-Signature-N header; any match = authentic.
function verify(rawBody, headers, secret) {
  const expected = crypto.createHmac('sha256', secret).update(rawBody).digest('base64');
  const signatures = Object.keys(headers)
    .filter((h) => h.toLowerCase().startsWith('x-docusign-signature-'))
    .map((h) => headers[h]);
  return signatures.some((sig) => {
    try {
      return crypto.timingSafeEqual(Buffer.from(sig), Buffer.from(expected));
    } catch {
      return false; // length mismatch = not a match
    }
  });
}

Python:

import hmac, hashlib, base64

def verify(raw_body: bytes, headers, secret: str) -> bool:
    expected = base64.b64encode(
        hmac.new(secret.encode(), raw_body, hashlib.sha256).digest()
    ).decode()
    sigs = [v for k, v in headers.items() if k.lower().startswith("x-docusign-signature-")]
    return any(hmac.compare_digest(sig, expected) for sig in sigs)

Important: Verify against the exact raw body bytes DocuSign sent. Any re-serialization (pretty-printing, JSON round-trip) changes the bytes and breaks the signature.