Historical balance requests with block identifiers from before account was created

Hey Rosetta team,

I’m working on adding support for historical balance requests in Mina’s Rosetta implementation and need clarification on a certain nuance.

If an /account/balance request is made for account_identifier A with block_identifier B but account A was created later than the block referenced by B, should we return a balance of 0 or an error?

Thanks,
Omer

Hi Omer!

Returning 0 in this case should be fine. But I would like to understand how Mina protocol determines that an account was created at a particular block. By creation, do you mean the account first appeared on chain at a particular block?

Thanks!

Thanks for getting back to us! We’re returning 0 already so we’ll just continue doing that.

And that’s right, by “account A was created later than the block referenced by B” I just meant that the account had not appeared on any blocks on the chain as of the block referenced by B.

Great and sounds good! Thank you! :raised_hands: