Build a Modern Treasury ledger to track marketplace escrow balances and trigger payouts on delivery confirmation

Verified steps

1. Create a ledger via POST /api/ledgers, then define ledger accounts for each actor: platform_cash (asset), buyer_payable (liability), seller_receivable (asset), and platform_fee (revenue), following double-entry principles.
2. When a buyer pays, record a ledger transaction with two entries: debit platform_cash and credit buyer_payable in equal amounts; link this ledger transaction to the Modern Treasury PaymentOrder representing the incoming ACH or wire.
3. On delivery confirmation, transition the buyer_payable to the seller: record a ledger transaction debiting buyer_payable and crediting seller_receivable; simultaneously debit seller_receivable and credit platform_fee for your commission amount.
4. Trigger the actual payout via POST /api/payment_orders with payment_type=ach, direction=credit, originating_account_id (your bank account), counterparty_id (the seller's bank counterparty), and amount; link the payment order to the ledger transaction via metadata.
5. Subscribe to payment_order.status_changed webhooks to detect COMPLETED or FAILED states; on FAILED, reverse the ledger entries to restore seller_receivable balance and flag for retry.
6. Use GET /api/ledger_accounts/{id} with balance_types[]=available to retrieve real-time available balance per ledger account; use this to prevent over-disbursement when multiple concurrent payouts draw from the same pool.