Create Funding Account

Creates a funding account and sets up payment details. settlement_destination.type=CUSTOMER_NGN_BALANCE is generally available for permanent funding accounts: permanent NGN virtual-account deposits are retained for that customer, while supported USDC/USDT deposits on any deposit-enabled chain are automatically converted into that customer's NGN balance. NGN_BALANCE retains NGN at merchant level, and INTERNAL_BALANCE preserves the existing automatic settlement into the merchant balance. Read customer balances with GET /v1/customers/{id}/balances and create an NGN bank transfer with debit_scope=CUSTOMER, debit_currency=NGN, and on_behalf_of.customer_id to pay from that balance. Provider-backed instructions include provider_availability, which reports each provider's current funding-account service state. Permanent NGN creation can continue through Paystack when Flutterwave is UNAVAILABLE and the customer has verified bank details; the response still includes the Flutterwave instruction with provider_availability.status set to UNAVAILABLE. The endpoint returns 503 PROVIDER_UNAVAILABLE only when no configured permanent NGN provider can accept the request, or when the single provider required for another rail is unavailable. Include developer_fee.percentage to keep 0% to 50% of each received deposit; deposit responses and webhooks show the developer fee and customer amount separately from Daya fees. Native SOL uses a PERMANENT CRYPTO_ADDRESS account on SOLANA with INTERNAL_BALANCE settlement and no developer fee. Requires an idempotency key in the X-Idempotency-Key header.