Enroll one or more card + grade combinations in CardHedge's price tracking.

Once subscribed, Card Hedge sends price changes to the webhook URL registered for your client_id. Before subscribing, provide Card Hedge with the public webhook URL that should receive these updates.

Webhook delivery

Your URL must accept an HTTP POST with an application/json body. For the first subscription in the request example, a price update is posted in this format:

{
  "message_type": "price_update",
  "external_id": "test_123",
  "card_id": "1586812246197x228181943611293700",
  "grade": "PSA 10",
  "price": "45.00"
}

external_id echoes the reference supplied with the subscription so you can match the update to the correct record in your system. If you omit it, the CardHedge card_id is used.

Requires a CardHedge Client ID (client_id). Contact Card Hedge if you don't have one.

• external_id is your own reference for the subscription; defaults to the card_id when omitted.
• Up to 100 subscriptions per request, processed in parallel.
• Individual failures do not affect other subscriptions — the response always returns HTTP 200 with per-item success/failure status.

{
  "results": [
    {
      "card_id": "1586812246197x228181943611293700",
      "external_id": "my_ref_123",
      "grade": "PSA 10",
      "success": true
    },
    {
      "card_id": "1699670576265x928796749151534600",
      "error": "Card not found",
      "external_id": "1699670576265x928796749151534600",
      "grade": "PSA 9",
      "success": false
    }
  ],
  "total_requested": 2,
  "total_successful": 1
}