For some addresses, if you call getSignaturesForAddress to get its entire transaction history and sum up all of the balance changes (via calculating postBalances[i] - preBalances[i]) you almost always end up with a number that's slightly larger (about 0.0006 SOL or more) than if you simply call getBalance from an RPC node.
Does anyone know why this discrepancy might exist? Rent? Hidden fees?
It's likely ignoring the rent-exempt amount when computing getBalance. However the rent exemption is about 0.00089088, so I'm not sure why you would get 0.0006
Things you might be doing wrong.
You need to add the difference to a balance that you initialize at 0
let balance = 0
loop transactions {
balance += postBalances[i] - preBalances[i]
}
And make sure the i you choosing is the wallet you're trying to extract the balance each time. Order of the accounts changes
And finally, make sure you extract all the Transactions. for getSignaturesForAddress
the limit: <number> - maximum transaction signatures to return (between 1 and 1,000, default: 1,000).
So you need to do 2 requests if you have over 1000 transactions. Specify the last transaction signature in before: <string> - start searching backward from this transaction signature. If not provided the search starts from the top of the highest max confirmed block.
