# Orb Webhooks

## When to Use This Skill

* Setting up Orb webhook handlers
* Debugging Orb signature verification failures
* Understanding Orb event types and payloads
* Handling usage-based billing, subscription, or invoice events

## Verification (core)

Orb signs every webhook with HMAC-SHA256 over the literal string `v1:{X-Orb-Timestamp}:{rawBody}`. The hex digest is delivered in `X-Orb-Signature` prefixed with `v1=` (e.g. `v1=abc123…`). The ISO 8601 timestamp arrives separately in `X-Orb-Timestamp`. Use the raw request body — don't `JSON.parse` first.

The `orb-billing` SDK (npm and PyPI) does not expose an `unwrap()`/`constructEvent()` helper at this time, so manual HMAC verification is the canonical path in every framework.

Node:

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

function verifyOrbSignature(rawBody, signatureHeader, timestamp, secret) {
  if (!signatureHeader || !timestamp) return false;
  const provided = signatureHeader.startsWith('v1=') ? signatureHeader.slice(3) : signatureHeader;
  const expected = crypto
    .createHmac('sha256', secret)
    .update(`v1:${timestamp}:${rawBody}`)
    .digest('hex');
  try {
    return crypto.timingSafeEqual(Buffer.from(provided, 'hex'), Buffer.from(expected, 'hex'));
  } catch {
    return false;
  }
}

```

Python:

```python
import hmac, hashlib

def verify_orb_signature(raw_body: bytes, signature_header: str, timestamp: str, secret: str) -> bool:
    if not signature_header or not timestamp:
        return False
    provided = signature_header[3:] if signature_header.startswith("v1=") else signature_header
    expected = hmac.new(
        secret.encode(), f"v1:{timestamp}:".encode() + raw_body, hashlib.sha256
    ).hexdigest()
    return hmac.compare_digest(provided, expected)

```

> For complete handlers with route wiring, event dispatch, and tests, see:
> 
> * [examples/express/](https://github.com/hookdeck/webhook-skills/tree/main/skills/orb-webhooks/examples/express/) — Full Express implementation
> * [examples/nextjs/](https://github.com/hookdeck/webhook-skills/tree/main/skills/orb-webhooks/examples/nextjs/) — Next.js App Router implementation
> * [examples/fastapi/](https://github.com/hookdeck/webhook-skills/tree/main/skills/orb-webhooks/examples/fastapi/) — Python FastAPI implementation

## Common Event Types

| Event | Description |
| --- | --- |
| `customer.created` | New customer created |
| `customer.credit_balance_dropped` | Prepaid credit balance fell below a threshold |
| `subscription.created` | New subscription created |
| `subscription.started` | Subscription's billing period started |
| `subscription.ended` | Subscription ended |
| `subscription.plan_changed` | Subscription moved to a different plan |
| `subscription.usage_exceeded` | Usage crossed a configured threshold |
| `invoice.issued` | Invoice finalized and issued to customer |
| `invoice.payment_succeeded` | Invoice paid successfully |
| `invoice.payment_failed` | Invoice payment attempt failed |
| `data_exports.transfer_success` | Scheduled data export delivered |

> For full event reference, see [Orb Webhook Documentation](https://docs.withorb.com/integrations-and-exports/webhooks)

## Environment Variables

```bash
ORB_WEBHOOK_SECRET=your_webhook_signing_secret   # Per-endpoint secret from Orb dashboard

```

The webhook signing secret is configured per webhook endpoint in the Orb dashboard — it is not your account API key.

## Local Development

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

```

## Reference Materials

* [references/overview.md](https://github.com/hookdeck/webhook-skills/blob/main/skills/orb-webhooks/references/overview.md) — Orb webhook concepts and events
* [references/setup.md](https://github.com/hookdeck/webhook-skills/blob/main/skills/orb-webhooks/references/setup.md) — Dashboard configuration
* [references/verification.md](https://github.com/hookdeck/webhook-skills/blob/main/skills/orb-webhooks/references/verification.md) — Signature verification details and gotchas