Zoho Assist API Authentication using OAuth 2.0 

Zoho Assist APIs use OAuth 2.0 for authentication. To make API calls, you must generate an access token from Zoho Accounts and pass it as a Bearer token in the Authorization header.

Authentication flow (high-level):

• Redirect the user to Zoho Accounts to obtain an authorization code

• Exchange the authorization code for access and refresh tokens

• Use the access token in API requests and refresh it when it expires

References 

For complete details on app registration, OAuth concepts, limits, etc., refer to the Zoho Accounts OAuth Documentation.