API Keys used to not be the APP ID?

I'm upgrading our FB app to use the new SDK. Noticed that API Keys are now the same as the App ID. We're still sending over our old API Key for tokens. Are the old API Keys Obsolete/Deprecated... Should I change all of our to api keys to app id's?

What's the logic behind this? Or at the least- any sort of migration, cut off dates for this. Where would/could I search f开发者_运维技巧or docs on this? Keywords?

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Yes, if you haven't migrated by now, your old app will not work. You will need to change over to the new oauth2 ASAP! :)