I'm starting to integrate our site with Zoho CRM, and there seem to be 2 API versions:

1) https://www.zoho.com/crm/help/api/

2) https://www.zoho.com/crm/newhelp/api/v2/#introduction

The V2 API looks great - but I can't see how to authenticate - it says OAuth, but doesn't tell me what the Token Request/Access/Refresh URLs are, or where I can get a Client ID & Secret, and the Zoho-Authtoken authorization fails. The V1 API has better documentation of Authentication, but worse documentation of API responses, (none).

Which API should I be using? If V2, where do I get the info needed to authorize. If V1, is there documentation of responses?

I want my integration to last, so if V2 is the future I should start using it now.

Thanks,

John