I need to extend Odoo’s Accounting module so it can talk to my existing external systems in real time. The sole aim of this customization is smooth, reliable integration—whenever an invoice, payment, or reconciliation is created or updated in one place, it must instantly appear in the other platforms and vice-versa. You’ll be building a clean, reusable Odoo add-on that handles authentication, data mapping, and error handling through Odoo’s ORM and JSON-RPC/XML-RPC calls, while consuming the third-party REST or SOAP endpoints those systems expose. Once the code is ready, you’ll install it on my POC (proof of concept) server, prove that two-way sync works, then document the exact steps so I can reproduce the setup in production. Speed matters: I’d like to see a working proof of concept within the first few days and the entire job finished as soon as possible. Access to a fresh POC database is ready, and I’m available for quick answers so you’re never blocked. If you have shipped similar Accounting integrations before, let me know which systems you connected and how you handled authentication.