# POST Create a webhook subscription

Registers an HTTPS callback for one topic. Requires `webhooks:write` and an `Idempotency-Key`. The response contains the signing `secret`; store it securely because later subscription responses never return it. Verify deliveries using https://www.signcustomiser.com/help/integrations/subscribe-to-webhooks/. Retrying the exact request and key replays the original response without creating a second subscription or rotating the secret. Registration does not itself enable delivery: `product:created` and `order:created` emit only for Stores with custom API access. Contact Sign Customiser support to confirm eligibility if those events do not arrive.

- Source URL: https://www.signcustomiser.com/help/api/v3-post-create-a-webhook-subscription/
- Markdown URL: https://www.signcustomiser.com/help/api/v3-post-create-a-webhook-subscription.md
- Group: Webhook subscriptions
- Method: POST
- Path: /api/v3/webhook-subscriptions
- Auth: Bearer token
- Required scopes: `webhooks:write`

## Body parameters

- topic (string, optional): No description provided.
- url (string, optional): No description provided.

## Request body example

```json
{
  "topic": "product:created",
  "url": "https://example.com/webhooks/sign-customiser"
}
```

## cURL example

```bash
curl https://web.signcustomiser.com/api/v3/webhook-subscriptions \
  --request POST \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer YOUR_API_TOKEN' \
  --header 'Content-Type: application/json' \
  --data '{
  "topic": "product:created",
  "url": "https://example.com/webhooks/sign-customiser"
}'
```

## Response examples

### 201 POST 201 example 1

```json
{
  "data": {
    "object": "webhook_subscription",
    "id": 42,
    "topic": "product:created",
    "url": "https://example.com/webhooks/sign-customiser",
    "created_at": "2026-07-22T00:00:00Z",
    "updated_at": "2026-07-22T00:00:00Z"
  },
  "links": {
    "self": "https://web.signcustomiser.com/api/v3/webhook-subscriptions/42",
    "documentation": "https://www.signcustomiser.com/help/api/"
  },
  "meta": {
    "api_version": "v3",
    "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
  }
}
```

### 400 Missing idempotency key

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/missing_idempotency_key",
  "title": "Missing idempotency key",
  "status": 400,
  "code": "missing_idempotency_key",
  "detail": "Provide an Idempotency-Key header for this write.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 401 Missing API key

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/missing_api_key",
  "title": "Missing API key",
  "status": 401,
  "code": "missing_api_key",
  "detail": "Provide a store API key as a bearer token.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 403 Insufficient scope

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/insufficient_scope",
  "title": "Insufficient scope",
  "status": 403,
  "code": "insufficient_scope",
  "detail": "This operation requires the webhooks:write scope.",
  "required_scopes": [
    "webhooks:write"
  ],
  "granted_scopes": [
    "webhooks:read"
  ],
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 409 Idempotency conflict

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/idempotency_key_conflict",
  "title": "Idempotency key conflict",
  "status": 409,
  "code": "idempotency_key_conflict",
  "detail": "This Idempotency-Key was already used for a different request body on this operation.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 413 Request body too large

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/request_too_large",
  "title": "Request too large",
  "status": 413,
  "code": "request_too_large",
  "detail": "The request body must not exceed 2 MiB.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 422 Unsafe callback

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/validation_failed",
  "title": "Validation failed",
  "status": 422,
  "code": "validation_failed",
  "detail": "The request payload failed validation.",
  "errors": [
    {
      "pointer": "/url",
      "code": "safe_outbound_url",
      "detail": "The url must be a public HTTPS URL."
    }
  ],
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 429 Rate limited

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/rate_limited",
  "title": "Too many requests",
  "status": 429,
  "code": "rate_limited",
  "detail": "You have exceeded the request limit for this API key.",
  "retry_after": 60,
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```