Refresh token and Access token in facebook API

Question

When we do oauth2 on google api, we get an access token and a refresh token. Suppose I'm writing a service and I want to periodically poll for changes I can just use refresh token to get fresh access tokens every time the current access token gets invalidated. This is called offline access.

Is there any way to do the same in facebook? Is there an offline access version similar to that of google api.

Thanks.

Answer 1

For offline access, you need to exchange your short-lived access token for a new access token, before it expires. Facebook has a single type of access token (no refresh tokens). A about-to-expire access token should fetch you a new access token.

To manually extend the tokens using a Graph API endpoint ::

GET /oauth/access_token?  
    grant_type=fb_exchange_token&           
    client_id={app-id}&
    client_secret={app-secret}&
    fb_exchange_token={short-lived-token}

Quoting FB's documentation from here ::

Apps are unable to exchange an expired short-lived token for a long-lived token. The flow above only works with short-lived tokens that are still valid. Once they expire, your app must send the user through the login flow again.

Do read the Expiration and Extending Tokens portion of the documentation link that I have mentioned for further clarification.