Creating An Event With An App Token

When an event is created on our system I want to create the event on Facebook via our page. This is an entirely server-side process with no user interaction.

I've linked my page to my app, grabbed the "app token" for my application from https://developers.facebook.com/tools/access_token and tried to create an event by POSTing to /mypage/events but I just get (OAuthException - #1) An unknown error has occurred.. I'm assuming app tokens don't have access to create events for my page.

I can use a page token but this expires after 60 days and I'll have to keep updating the token. Is there a way to have this token last forever? I can renew it in code but it requires a user access token.

What's the best way to go about this?

You cannot use an app token to create an event on behalf of a page. You must use a page token and if you follow scenario 5 listed at https://developers.facebook.com/roadmap/offline-access-removal/, the page token will have no expiry.

Exchange the short-lived user access token for a long-lived access token using the endpoint and steps explained earlier. By using a long-lived user access token, querying the [User ID]/accounts endpoint will now provide page access tokens that do not expire for pages that a user manages. This will also apply when querying with a non-expiring user access token obtained through the deprecated offline_access permission.