im basically trying to create a token bridge between evm and moralis db.
I want people to be able to send their erc20 to a smart contract which locks it. the token then shows up on the moralis db. (this is the easy part)
When the token is on the moralis db it can be manipulated, the user balance can change etc etc. The benefit of this is that altering balances is free, downside is its happening on a centralized server. but nevertheless thats not part of the discussion.
Now the problem is when the user is ready to bridge from moralis db back to evm how could this be achieved by the user simply calling the amount they are eligible to withdraw from the contract, which would be goverened by their balance on the Moralis DB (because it most likely will not be the same balance they sent to the bridge in the first place).
So this is where I dont want the user to be able to change the tx parameters. I want the withdraw amount to be dictated by the Moralis DB and the user can not change it, they can only sign the tx.
Once signed the smart contract releases the tokens back to the user on the EVM, and the balance in the Moralis DB is deducted accordingly.