Commerce Layer Webhooks Skill

When to Use This Skill

• How do I receive Commerce Layer webhooks?
• How do I verify Commerce Layer webhook signatures?
• How do I handle orders.place, orders.approve, or orders.pay events?
• Why is my Commerce Layer X-CommerceLayer-Signature verification failing?
• Setting up a Commerce Layer callback endpoint for order/shipment events

Verification (core)

Commerce Layer signs the raw request body with HMAC-SHA256 keyed on the webhook's shared_secret and sends the digest as base64 in the X-CommerceLayer-Signature header. The triggering topic is in X-CommerceLayer-Topic. The shared_secret is returned once, in the response when you create the webhook (POST /api/webhooks) — it is not the same as your API credentials.

Read the raw body, NOT the parsed one. Re-serializing parsed JSON changes bytes (key order, whitespace) and breaks the signature. Commerce Layer has no SDK verify helper, so verify manually (this matches the official docs example).

Node:

const crypto = require('crypto');

function verifyCommerceLayerSignature(rawBody, signature, sharedSecret) {
  if (!signature) return false;
  const expected = crypto
    .createHmac('sha256', sharedSecret)
    .update(rawBody) // rawBody is a Buffer/string — never JSON.parse first
    .digest('base64');
  try {
    return crypto.timingSafeEqual(Buffer.from(signature), Buffer.from(expected));
  } catch {
    return false; // length mismatch = invalid
  }
}

Python:

import hmac, hashlib, base64

def verify_commercelayer_signature(raw_body: bytes, signature: str, shared_secret: str) -> bool:
    if not signature:
        return False
    expected = base64.b64encode(
        hmac.new(shared_secret.encode(), raw_body, hashlib.sha256).digest()
    ).decode()
    return hmac.compare_digest(signature, expected)

For complete handlers with route wiring, event dispatch, and tests, see:

• examples/express/
• examples/nextjs/
• examples/fastapi/

Common Event Types (Topics)

Topics use the format {resource}.{trigger}.

Commerce Layer supports 100+ topics across orders, customers, shipments, returns, refunds, authorizations, captures, gift_cards, and more. For the full list, see references/overview.md and the Commerce Layer webhooks docs.

Payload: JSON:API format, identical to fetching the resource via the REST API — { "data": { "id", "type", "attributes", "relationships" } }. For .destroy topics only data.id is populated (other attributes are null).

Environment Variables

COMMERCELAYER_SHARED_SECRET=your_webhook_shared_secret   # returned when you create the webhook

Local Development

# Start tunnel (no account needed)
npx hookdeck-cli listen 3000 commercelayer --path /webhooks/commercelayer

Reliability & Retries

• Your endpoint must return a 2xx status within 5 seconds.
• Failed deliveries are retried up to 10 times.
• After 5 unsuccessful attempts, the organization owner/admins are notified.
• After 30 consecutive failures the webhook's circuit breaker trips (circuit_state → open, tracked via circuit_failure_count) and it must be reset manually. (closed is the healthy default state.)

Verify fast, then do slow work asynchronously so you always answer within 5 seconds.

Reference Materials

• references/overview.md - Commerce Layer webhook concepts and topics
• references/setup.md - Create a webhook, get the shared_secret
• references/verification.md - Signature verification details and gotchas