Adaptar Facturación PHP a VERIFACTU

I currently have my own electronic invoicing application written in PHP. I want it to fully comply with Spanish regulations and, most importantly, to connect exclusively to the VERIFACTU platform for invoice validation before sending them to my clients or to the AEAT.

The task consists of:

Incorporating into the core of my system a PHP module that sends each invoice to the VERIFACTU API, receives the validation response, and updates the document status.

Adjusting invoice formats (XML Facturae / JSON) as needed so they pass validation without errors.

Providing unit and integration tests that demonstrate the complete workflow.

Delivering a brief installation and user manual so my team can deploy the changes to production.

I will provide access to the Git repository, a test database, and VERIFACTU sandbox credentials. The work must remain 100% in PHP, respecting the existing architecture and without adding new frameworks that alter the project structure.

If you have prior experience integrating Spanish invoicing platforms or handling the Facturae specification from PHP, I would be happy to work with you and review your proposals.