[i386]

You need to keep using the tokens for them to remain valid. Have a daily job that fetches the users basic profile info like /accounts/me to keep them valid

[mrloop]

I'm building an integration that will use a long lived token once a month. In your experience will a long lived token expiry if not used for a month? How long do they remain valid until expiring from not being used?

[i386]

About three months for long lived tokens in my experience. My recommendation would be to use them weekly.