# Medusa Webhooks

These are **Medusa Cloud** webhooks: one endpoint per organization that is notified about builds and deployments. Self-hosted (open-source) Medusa has no built-in outbound webhooks, and Medusa application events such as `order.placed` are internal events handled by subscribers, not webhooks sent to your URL.

## When to Use This Skill

* How do I receive Medusa Cloud webhooks?
* How do I verify the `X-Medusa-Signature` header?
* How do I handle `build.succeeded`, `build.failed`, or `deployment.succeeded` events?
* How do I notify a team or trigger a pipeline when a Medusa deployment finishes?
* Why is my Medusa webhook signature verification failing?

## Verification (core)

Medusa sends `X-Medusa-Signature: t=<unix seconds>,v1=<hex>`. `v1` is the hex HMAC-SHA256 of `"<t>.<raw body>"`, keyed with the endpoint's signing secret as a UTF-8 string. Always sign over the **raw body**.

The docs show an optional freshness check on `t`. Medusa re-signs each of its own retry attempts, but **Hookdeck retries and replays resend the original timestamp, so a 5-minute window rejects late retries**. The check is therefore opt-in here (`MEDUSA_TIMESTAMP_TOLERANCE_SECONDS`, default `0` = off). [references/verification.md](https://github.com/hookdeck/webhook-skills/blob/main/skills/medusa-webhooks/references/verification.md) shows where the window is applied and how to drop or widen it.

```javascript
const crypto = require('crypto');

// toleranceSeconds = 0 (default) skips the timestamp window; a positive value opts in
function verifyMedusaWebhook(rawBody, header, secret, toleranceSeconds = 0) {
  if (!header) return false;
  const parts = header.split(',').map((p) => p.trim().split('='));
  const t = parts.find(([k]) => k === 't')?.[1];
  const sigs = parts.filter(([k]) => k === 'v1').map(([, v]) => v);
  if (!t || !/^\d+$/.test(t) || sigs.length === 0) return false;
  if (toleranceSeconds > 0 && Math.abs(Date.now() / 1000 - Number(t)) > toleranceSeconds) return false; // opt-in replay window
  const expected = crypto.createHmac('sha256', secret).update(`${t}.`).update(rawBody).digest('hex');
  return sigs.some((sig) => {
    try { return crypto.timingSafeEqual(Buffer.from(sig), Buffer.from(expected)); }
    catch { return false; } // length mismatch
  });
}

```

Medusa has no standalone verification SDK (the docs show a manual Node.js check), so verification is manual in every framework. This is **not** Standard Webhooks (no `webhook-id` / `webhook-timestamp` headers). In the Express example, read the body with `express.raw({ type: '*/*' })` so any content type verifies.

> **For complete handlers with tests**, see [examples/express/](https://github.com/hookdeck/webhook-skills/tree/main/skills/medusa-webhooks/examples/express/), [examples/nextjs/](https://github.com/hookdeck/webhook-skills/tree/main/skills/medusa-webhooks/examples/nextjs/), [examples/fastapi/](https://github.com/hookdeck/webhook-skills/tree/main/skills/medusa-webhooks/examples/fastapi/).

## Common Event Types

Every delivery is a `POST` with a JSON object `{ id, type, data, created_at }` plus an `X-Medusa-Event` header matching `type`. Route on `type`:

| Event | Triggered When | Common Use Cases |
| --- | --- | --- |
| `build.created` | A build is created for an environment (after a push to its branch) | Track build starts |
| `build.succeeded` | A build completes successfully | Post to chat, trigger smoke tests |
| `build.failed` | A build fails | Alert the team |
| `build.canceled` | A build is canceled | Update status boards |
| `deployment.created` | A deployment is created for an environment | Mark a release as in progress |
| `deployment.succeeded` | A deployment completes successfully | Announce release, run post-deploy checks |
| `deployment.failed` | A deployment fails | Page on-call |
| `deployment.canceled` | A deployment is canceled | Update status boards |

Each payload's `data` carries `organization`, `project`, `environment`, and `build` or `deployment` objects. See [references/overview.md](https://github.com/hookdeck/webhook-skills/blob/main/skills/medusa-webhooks/references/overview.md).

## Environment Variables

```bash
MEDUSA_WEBHOOK_SECRET=your_endpoint_signing_secret   # Signing Secret on the endpoint card in Cloud
MEDUSA_TIMESTAMP_TOLERANCE_SECONDS=0                 # Optional replay window; a positive value opts in

```

## Local Development

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

```

## Reference Materials

* [references/overview.md](https://github.com/hookdeck/webhook-skills/blob/main/skills/medusa-webhooks/references/overview.md) - Medusa Cloud webhook concepts, events, payload shape
* [references/setup.md](https://github.com/hookdeck/webhook-skills/blob/main/skills/medusa-webhooks/references/setup.md) - Create the endpoint in Cloud and get the signing secret
* [references/verification.md](https://github.com/hookdeck/webhook-skills/blob/main/skills/medusa-webhooks/references/verification.md) - Signature verification details, gotchas, timestamp window