Best way to get all ERC20 holdings for multiple addresses

Question

I have a set of addresses (20K +) and a set of tokens (3K+) in my database.`

I want to store their token holdings current state based on an interval lets say every 30 minutes. I got an Infura Enterprise subscription but I dont know what is the most efficient way doing this using web3.

The only way I know which results in way too many requests would be:

for token in tokens web3 contract instance for token for address in addresses token.balanceof(address)

Is there any other way to do this? Like is there a possibility I didnt notice where I could send an array of addresses to a contract instance balanceof function instead of just a single one per request?

Regards

Answer 1

You can use the Zapper API. It takes an array of addresses and can return tokensets or other properties as well. 20k is a lot of addresses so I suggest pulling in these properties by using a set of loops and storing them in your own array.

Here is a link to the API swagger:

https://api.zapper.fi/api/static/index.html#/Protocol%20Balances/BalanceController_getProtocolBalancesV2

Hope this helps :)