Do all users need to have a Zoho account for accessing my Office Integrator solution?

Do all users need to have a Zoho account for accessing my Office Integrator solution?

Not necessary! 

Office Integrator solution does not require each user to have a Zoho account. As all API requests are authenticated through a unique API key associated with a single Zoho account - the Office Editors embedded into your web application will only validate that specific API key for all document open/edit requests.