Redeem Steam key to account with Steam OpenID like Humble Bundle?

Question

Humble Bundle has started requiring the user to sign in through Steam's OpenID authentication where it then redeems the Steam key on the user's account. I was unable to find any documentation on this subject.

Is the system open for redeeming games on connected accounts to other developers to use, other than Humble Bundle? If so, how can this be done? I'm looking for example code or a link to documentation.

Answer 1

Steam has removed this functionality. As a result, Humble Bundle doesn't support this anymore either.

Answer 2

There is no public documentation. OAuth use is private for the moment. Only some pages have it, like Humble Bundle and DOTA 2. The rest of us can only use OpenID.