# getSeatsPurchaseUrl

The in-app Billing page URL where a human buys extra seats. The agent cannot buy. Decide "at cap" from getBillingSummary's `extraSeats.seatsUsed` vs `extraSeats.seatsCap` (total, purchased seats included), never the plan-only `featureLimits.seatsCap`. Price: getAddOnPrices.

- Call: `POST https://server.goliathdata.com/api/v1/call` with `{ "operationId": "getSeatsPurchaseUrl", "variables": {...} }`
- Scope: `READ`
- Type: query
- Idempotency: a read; rejects `Idempotency-Key`
- Rate-limited: no

## Variables

None.

## Response (data, an example)

```json
{
  "billing": {
    "getSeatsPurchaseUrl": "…"
  }
}
```

## Example

```bash
curl https://server.goliathdata.com/api/v1/call \
  -H "Authorization: Bearer $GOLIATH_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "operationId": "getSeatsPurchaseUrl",
    "variables": {}
  }'
```