Custom Open-Banking WooCommerce Integration

I’m looking to replace the usual card-processor checkout in WooCommerce with a true open-banking flow that moves money bank-to-bank without routing through Plaid, Yodlee, TrueLayer or any similar middleman. In other words, I need a purpose-built Payment Initiation Service (PIS) plugin that speaks directly to the banks’ PSD2 / OBIE APIs.

Scope of work
• Build a lightweight WooCommerce extension (PHP, WordPress coding standards) that presents “Pay by Bank” at checkout, initiates the payment with the customer’s chosen bank, redirects for Strong Customer Authentication, and returns to the store once the transfer is authorised.
• On success, mark the WooCommerce order as paid and log the transaction reference; on failure or cancellation, handle and surface the appropriate status message.
• Provide an admin screen where I can enter client IDs, certificates or any other credentials needed for each supported bank, plus a test/sandbox mode.
• Include clear installation instructions and a short developer-level read-me so future maintenance is straightforward.

Acceptance test
A demo order completed in a sandbox bank environment should automatically update to “Processing / Paid” in WooCommerce, with the transaction reference stored in the order meta.

If you have hands-on experience with PSD2 open banking, SCA redirect flows and WordPress plugin architecture, I’d love to hear how you would approach this.