How to deploy a contract on Polygon/Ethereum/BSC with shared state?

Question

I would like to deploy an ERC-20 token on multiple chains : Ethereum, Polygon and the Binance Smart Chain while keeping the same address ideally. But I have literally zero idea on how to do that, I can't find a clear answer while googling.

How could I share the circulating supply between the networks? What if I need shared state between networks? My guess is that I would need some kind of intermediary, what would that be and how would it propagate the transactions between the various networks ?

Answer 1

while keeping the same address ideally.

Addresses are interchangeable between the networks. The smart contract address is the deployer address + nonce. You just use the same private key to deploy the address on every network.

I need shared state between networks?

It is impossible. Each network is independent of each others and they do not verify blocks across the networks. The best you can get is some sort of message passing. Check this video on the topic from James Preswitch.