pylon-webhooks

Pylon Webhooks

Pylon is a B2B customer support platform. It delivers webhooks to a webhook destination you configure, signed with HMAC-SHA256. There is no official Pylon SDK — verify manually in every framework.

When to Use This Skill

• How do I receive Pylon webhooks?
• How do I verify Pylon webhook signatures?
• Why is my Pylon Pylon-Webhook-Signature verification failing?
• How do I handle Pylon issue events like issue.created or issue.updated?

Verification (core)

Pylon sends three headers with every delivery:

Header	Example	Purpose
Pylon-Webhook-Signature	hs256=9f8c…	HMAC-SHA256 signature, hs256= prefix + hex digest
Pylon-Webhook-Timestamp	1624235417	Unix seconds, part of the signed content
Pylon-Webhook-Version	2021-07	Payload schema version

The signed content is timestamp + "." + rawBody. Compute HMAC-SHA256 with your destination's secret (shown only once when you create the destination), prefix with hs256=, and compare against the header using a timing-safe check. Always verify against the raw request body — do not JSON.parse first.

Node (node:crypto, no dependency):

const crypto = require('crypto');

function verifyPylonWebhook(rawBody, timestamp, signatureHeader, secret) {
  if (!signatureHeader || !timestamp) return false;
  const expected = 'hs256=' + crypto
    .createHmac('sha256', secret)
    .update(`${timestamp}.`)      // Pylon signs timestamp + "." + rawBody
    .update(rawBody)              // rawBody is a Buffer/string, never parsed JSON
    .digest('hex');
  try {
    return crypto.timingSafeEqual(Buffer.from(signatureHeader), Buffer.from(expected));
  } catch {
    return false; // length mismatch = invalid
  }
}

Python (hmac, no dependency):

import hmac, hashlib

def verify_pylon_webhook(raw_body: bytes, timestamp: str, signature_header: str, secret: str) -> bool:
    if not signature_header or not timestamp:
        return False
    signed = timestamp.encode() + b"." + raw_body  # timestamp + "." + rawBody
    expected = "hs256=" + hmac.new(secret.encode(), signed, hashlib.sha256).hexdigest()
    return hmac.compare_digest(signature_header, expected)