Integration of Manager to clients existing Websites or Apps

Dear All
Please do anyone have the knowldege or information whether Manager (the Cloud version) have the API required to integrate with existing website or Apps previously used by the clients. For example loan calculator for small mircofinance bank? Or the exisiting website of the company to be integrated with Manager.
I have a client on microfinance bank who obtain savings and disburse loans to various savers or customers, they require an accounting software that can easily be integrated with their existing structure Mere seen the reports generated by Manager they fall in love with it. what do I do? Thank you.