D. Dental payment processing: collect appointment deposits

Use FRAGMENT checkout for dental payment processing when a patient accepts an appointment deposit. Create a Payment tied to the appointment and record settlement automatically. Keep the collected amount as a deposit until the practice approves applying it to completed treatment.

Use the Quickstart to configure your SDK and create a Ledger with the example schema. Use dental-practice as its ik. Configure a Payment Account before collecting payments. The schema marks assets/payments with payment: { "enabled": true }.

Collected funds remain a liability until an authorized application entry moves them to income. Processing fees are a separate expense.

Add dental_deposit to payments.types in your Schema. Its payment.amount reads the server-approved amount. Add the settlement accounting below to these fields; the complete schema contains both.

{
  "type": "dental_deposit",
  "typeVersion": 1,
  "status": "active",
  "payment": {
    "amount": "{{amount}}",
    "direction": "payin"
  }
}

Set accounting.settled.lines to these four lines. FRAGMENT supplies settled_amount and fragment_fee_amount; your application supplies appointment_id. The patient receives credit for the gross amount. The Payment Account receives that amount less the processing fee.

[
  {"key": "settlement", "account": {"path": "assets/payments"}, "amount": "{{settled_amount}}", "system": "payment_settlement_line"},
  {"key": "fee", "account": {"path": "assets/payments"}, "amount": "-{{fragment_fee_amount}}", "system": "payment_fee_line"},
  {"key": "receipt", "account": {"path": "liabilities/deposits:{{appointment_id}}/available"}, "amount": "{{settled_amount}}"},
  {"key": "fee-expense", "account": {"path": "expenses/payment-fees"}, "amount": "{{fragment_fee_amount}}"}
]

Resolve the approved dental appointment, payer, and amount from authenticated application records. Call createPayment with a stable idempotency key. Amounts are integer strings in USD cents. Return the Payment to your frontend; keep API credentials on your server.

const { createPayment } = await fragment.createPayment({
  ik: 'dental_deposit-1-v1',
  ledgerIk: 'dental-practice',
  type: 'dental_deposit',
  typeVersion: 1,
  parameters: { appointment_id: '1', amount: '10000' },
});
if (createPayment.__typename !== 'CreatePaymentResult') {
  throw new Error(createPayment.message);
}
return { payment: createPayment.payment };

Mount Checkout inside PaymentElements from @fragment-dev/payment-elements. Pass the Payment returned by your backend and the payer's email. The Payment starts in needs_payment_method. Your Pay button calls confirm() to charge the card.

Place checkout in the dental appointment screen. Use onConfirmed to update that screen. Verify the Payment's settled status on your backend before marking the receipt available.

import { Checkout, PaymentElements, type Payment } from '@fragment-dev/payment-elements';
import { PayButton } from './PayButton';

type Props = { payment: Payment; email: string; onConfirmed: () => void };

export const PaymentCheckout = ({ payment, email, onConfirmed }: Props) => (
  <PaymentElements>
    <Checkout
      payment={payment}
      billingDetails={{ email }}
      onConfirmed={onConfirmed}
      onError={(message) => console.error(message)}
    >
      <PayButton />
    </Checkout>
  </PaymentElements>
);

Disable the Pay button until checkout can confirm the Payment. Show errors beside the form so the customer can correct their card details.

import { usePayment } from '@fragment-dev/payment-elements';

export const PayButton = () => {
  const { confirm, canConfirm, isConfirming, isLoading, error } = usePayment();
  return <>
    <button type="button" disabled={isLoading || !canConfirm || isConfirming}
      onClick={() => canConfirm && confirm()}>Pay by card</button>
    {error && <p role="alert">{error}</p>}
  </>;
};

FRAGMENT posts settlement accounting automatically. Your application posts the separate business entry after authorization. Do not submit native settlement entries through addLedgerEntry.

Confirm the patient's accepted treatment estimate and deposit policy before creating the Payment. After settlement, apply $70 of the $100 receipt to completed dental treatment. The entry leaves $30 available. Your accounting policy determines the recognition date. Use the AddLedgerEntry mutation with these variables.

{
  "ik": "dental_deposit_apply-1-v1",
  "entry": {
    "ledger": {
      "ik": "dental-practice"
    },
    "type": "dental_deposit_apply",
    "typeVersion": 1,
    "parameters": {
      "appointment_id": "1",
      "amount": "7000"
    }
  }
}

These diagrams show a $100 card receipt followed by a $70 application, leaving $30 available. The assumed $3 fee illustrates accounting; it is not a pricing quote. FRAGMENT supplies the actual fee. Only dental_deposit_apply is posted by your application.

Store the Payment identifier with the dental appointment and operation key. A client callback alone does not establish settlement. Recover server-side status when the response is lost.

Authorize each application of collected funds against the business record. The balance condition prevents overuse; it does not replace business approval. Bind the payer, Ledger, record, and amount on your server. The application contract records these checks.

Confirm the patient's accepted treatment estimate and deposit policy before creating the Payment. Keep those decisions in the dental practice's application and pass only approved identifiers and amounts to FRAGMENT.

Use a sandbox Ledger and the documented test cards. Compare actual entries with the illustrative snapshots. The snapshots do not execute checkout or prove settlement.

1. Collect through checkout, then apply part of the settled funds after approval.
2. Verify the Payment status, gross receipt, fee expense, and remaining balance.
3. Retry with the same key and verify that the operation does not duplicate its financial effect.
4. Test a decline, a lost response, and concurrent collection requests.

1. A 
   Make Payments: Payment Types and embedded checkout
2. B 
   Quickstart: SDK and Ledger setup
3. C 
   Posting Ledger Entries
4. D 
   Payment schema
5. E 
   Illustrative accounting results
6. F 
   Payment and Ledger Entry request variables
7. G 
   Application contract