payment.partial

Same shape as payment.completed, with a shortfall field. Decide in your own integration whether a partial payment fulfils the order, requires a top-up from the payer, or should be refunded manually (Send Chain payments are non-custodial and final on-chain — there is no automatic refund path).

Payload (data)

{
  "livemode": false,
  "paymentId": "pay_test_00000000",
  "paymentRequestId": "req_test_00000000",
  "origin": { "type": "link", "id": "lnk_test_00000000", "title": "Sample link" },
  "supporter": { "id": "sup_test_00000000", "handle": "sample_supporter", "message": "Test payment" },
  "asset": "USDC",
  "chain": "base",
  "onchainAmount": "15000000",
  "feeAmount": "75000",
  "decimals": 6,
  "fiatValue": { "minor": 1500, "currency": "USD" },
  "rateBasis": "Locked",
  "txRef": "0xtesttx",
  "confirmations": 12,
  "completedAt": "2026-09-13T00:00:00Z",
  "shortfall": "500000"
}

See Webhooks overview for the envelope, headers, and signature verification shared by every event type.