As title, does oraclize deal with the case where the query transaction and callback transaction are executed in different side chains?

I mean in this situation:

A-B \ B'->C->D->....' canonical

Can such case happen that the query transaction are executed in block B while the callback transaction are in block B' ?

1 Answer 1


As the application developer, you need to handle this yourself. There's a little documentation here.

You send (and get returned) a queryId. You should check that this is valid inside your __callback() function when it is called.

You need to do this anyway, as the callback is public and can be called by anyone - so it could be an attack vector by a malicious party.

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