add decentro client and simple test

[gparuthi]

Design doc moved to notion

• [x] refactor API fetchJSON method
• [x] basic decentro test

[djudjuu]

@gparuthi

Questions

Remove balance column from user table.

i am not sure, I like this. We should know the user balance even if decentro is offline/unavailable. Or is this someting we should do in a later step? I need to get a better look at the decentro api

make sure the amounts on our side and wallet are always in sync

so, if not in the user-table, where would be our side?

Add UserModel with balance getter. LenderModel and BorrowerModel can inherit from this class.

I dont see why these need to be different atm. I thought none of them are using decentro direclty, so all they see is their bank account and their account on our site.... Can u elaborate this point a bit?

Borrower-Repayment and Lender-investments will be initiated by the user

let's break this down a bit more.

• A borrower repayment, probably would go to our bank account, then we can split it up to all the involved lenders/supporters.
• a lender investment: a lender can top up (one account affected only, no redistribution) or their funds can be auto-invested (no lender-action involved, rahter a consequence of the borrower accepting terms (the lender-update is part of a bulk of txs)

UPI payment app like Google Pay.

i know nothing about this.Looks like there is testing tooling here: https://developer.paytm.com/docs/testing-integration/ but I jus twant to point out, that this might be a bit longer for me to get into..

braindump

• I think it were nice if the flow always were like this: we register the change inside our FE -> send it to decentro, they confirm it -> we update our db accordingly -> FE updates based on our db
• Most updates are done by invoking dbClient.UpdatePortfolios(), so we need to wrap the decentroClient around that (or just put it before that if we want to be hacky). The other updates are done by sdk.change/set-user-cash-balance. So maybe we should refrain from making those calls directly, and instead only do WalletClient.update/set_balance(), which would internally then make a call to the truth-provider (decentro/web3) and then reflect that in our db

action items:

let's breakdown how we can start working on this:

• decentro account creation for users
• WalletClient that allows to do single balance-changes (flow: FE->decentro->DB->FE)
• bulk-updates as a consequence of accept/repay

[gparuthi]

Continuing the conversation in notion. I added information that should answer your questions. Let me know if I missed anything.