Previously, an API included a ticket that had a lifetime of 7 days, after which it would expire. The API had to be updated with a new ticket once every 7 days. This was getting tedious as there was no way you could automate this process. As a measure of minimizing manual effort involved, we introduced Authentication Tokens to API’s.
The Authentication Token is bound to an account. Generating it is a one-time activity, and is valid for eternity. This token can be used in all your API calls. All the tokens associated with your account can be managed in Zoho Accounts.
Authentication Token is certainly better in every way, so we strongly recommend all Developer API users to switch. Here is how you can generate the Authentication Token. In order to enforce this better alternative, we intend to discontinue support of API tickets and API key. API users will be notified well in advance.