# Xero Webhooks

## When to Use This Skill

* How do I receive Xero webhooks?
* How do I verify the `x-xero-signature` header?
* Why is my Xero webhook stuck as "inactive" / failing Intent to Receive (ITR)?
* How do I handle `CONTACT`, `INVOICE`, `CREDITNOTE`, or `SUBSCRIPTION` events?
* How do I fetch the changed record from a Xero webhook payload?

## Verification (core)

Xero signs the raw request body with HMAC-SHA256 keyed on the app's webhook signing key, base64-encodes the digest, and sends it in the `x-xero-signature` header. Capture the raw body before JSON parsing (parsing re-serializes the bytes and breaks the HMAC). Compare timing-safe. The official SDKs (`xero-node`, `xero-python`) do not ship a webhook-signature helper — verify manually.

Node:

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

function verifyXeroSignature(rawBody, signatureHeader, signingKey) {
  if (!signatureHeader) return false;
  const expected = crypto.createHmac('sha256', signingKey).update(rawBody).digest('base64');
  try {
    return crypto.timingSafeEqual(Buffer.from(signatureHeader), Buffer.from(expected));
  } catch {
    return false; // length mismatch = invalid
  }
}

```

Python:

```python
import hmac, hashlib, base64

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

```

> Intent to Receive (ITR): When you save the endpoint, Xero POSTs validation payloads and your server MUST respond within a few seconds: HTTP 200 when the signature matches, HTTP 401 when it does not. Anything else (including a 400) fails ITR and leaves the webhook inactive. Return `401` — not `400` — for a bad signature. The same verify-then-200/401 logic serves both ITR probes and real events.

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

## Payload Structure

Xero payloads are thin — they tell you what changed, not the record itself. Call `resourceUrl` (authenticated with an OAuth2 access token + `Xero-tenant-id`) to fetch the full record.

```json
{
  "events": [
    {
      "resourceUrl": "https://api.xero.com/api.xro/2.0/Contacts/<guid>",
      "resourceId": "<guid>",
      "eventDateUtc": "2024-05-01T12:00:00.000",
      "eventType": "CREATE",
      "eventCategory": "CONTACT",
      "tenantId": "<guid>",
      "tenantType": "ORGANISATION"
    }
  ],
  "firstEventSequence": 1,
  "lastEventSequence": 1,
  "entropy": "..."
}

```

Xero batches events and retries with backoff, so `events` may contain more than one item and the same event can arrive more than once — handle duplicates idempotently (dedupe on `resourceId` + `eventDateUtc`).

## Common Event Types

Dispatch on the combined `eventCategory/eventType` (e.g. `CONTACT/CREATE`).

| Category (`eventCategory`) | Types (`eventType`) | Triggered When |
| --- | --- | --- |
| `CONTACT` | `CREATE`, `UPDATE` | A contact is created or changed |
| `INVOICE` | `CREATE`, `UPDATE` | An invoice (ACCREC/ACCPAY) is created or changed |
| `CREDITNOTE` | `CREATE`, `UPDATE` | A credit note is created or changed |
| `SUBSCRIPTION` | `CREATE`, `UPDATE` | An app-store subscription changes (app partners) |

`tenantType` is `ORGANISATION` or `APPLICATION`.

> For the full reference, see [Xero webhooks documentation](https://developer.xero.com/documentation/guides/webhooks/overview/).

## Environment Variables

```bash
XERO_WEBHOOK_KEY=your_webhook_signing_key   # "Webhook signing key" from the app in the Xero developer portal

```

One signing key per app. Find it under your app's Webhooks tab at [developer.xero.com/app/manage](https://developer.xero.com/app/manage).

## Local Development

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

```

## Reference Materials

* [references/overview.md](https://github.com/hookdeck/webhook-skills/blob/main/skills/xero-webhooks/references/overview.md) - Xero webhook concepts, event categories, payload fields
* [references/setup.md](https://github.com/hookdeck/webhook-skills/blob/main/skills/xero-webhooks/references/setup.md) - Configure webhooks in the Xero developer portal, get the signing key, pass ITR
* [references/verification.md](https://github.com/hookdeck/webhook-skills/blob/main/skills/xero-webhooks/references/verification.md) - Signature verification, ITR status codes, gotchas