centrifuge/tinlake

Smart contracts for Tinlake, the on-chain securitization protocol for real-world assets

Tinlake Contracts

Open source implementation of Tinlake in Solidity. This repository contains the core contracts of Tinlake.

Tinlake is a set of smart contracts that allows companies and individuals to use tokenized non-fungible real-world assets as collateral to obtain liquidity.

For learning more about how Tinlake works, you can visit the Tinlake documentation.

Getting started

Tinlake uses foundry for development. Please install the foundry client. Then, run the following command to install the dependencies:

forge update

Testing

The tests for Tinlake are written in Solidity

Run all tests

forge test

Run specific tests

A regular expression can be used to only run specific tests.

forge test -m <REGEX>
forge test -m testName
forge test -m ':ContractName\.'

Deployment

To deploy Tinlake, you need to set up a .env file with the deployment parameters. A sample file can be found in .env.example.

To confirm that the .env file is set up correctly, run:

./bin/env-check.sh

Once you've double checked all the environment variables, the deployment can be started:

forge script script/deploy.s.sol:DeployScript --rpc-url $RPC_URL  --private-key $PRIVATE_KEY --broadcast --verify --etherscan-api-key $ETHERSCAN_KEY -vvvv

When the deployment is complete, you can print the list of deployed contracts:

ROOT_CONTRACT=0x0 forge script script/print_contracts.s.sol:PrintContractsScript --rpc-url $RPC_URL -vvvv

And you can also run the set of RPC tests against the newly deployed pool:

ROOT_CONTRACT=0x0 MAKER_RPC_TESTS=false forge script script/run-rpc-tests.s.sol:RunRPCTests --rpc-url $RPC_URL

Community

Join our public Discord: Centrifuge Discord.

tinlake's Issues

deploy latest version for MCD

Lightswitch

add tests for lightswitch and extend functionality if needed

check if rdiv could result in different rounding which lead to failed save math ops

add events for main transactions

add tinlake events for borrow and repay

• https://github.com/makerdao/dss/blob/master/src/lib.sol#L16 and https://github.com/dapphub/ds-note/blob/master/src/note.sol diverge. Find out which version to use

potential feature: flagging a loan as ongoing

This might be useful to prevent certain interaction patterns from the admin side if a loan is ongoing, currently we only limit these interactions from the borrower side by using the NFT owner check.

shelf and admin should have a file method for appraiser contract

add meta information to contract.json

update SimpleToken contract for Tinlake Playground

-- add metadata
-- add borrower address

consistent use and extensions of file pattern

every file method should have a bytes32 what.

Every contract which has a dependency on another contract should have file methods to change the dependency.

Example for reception.sol

    // --- Data ---
    DeskLike desk;
    ShelfLike shelf;
    PileLike pile;

 function file(bytes32 what, address addr) public auth {
        if (what == "pile") pile = PileLike(addr);
        else if (what == "shelf") shelf = ShelfLike(addr);
        else if (what == "desk") desk = DeskLike(addr);
        else revert();
    }

I think we should use the file pattern only for external configuration. If one core contract calls another core contract we should use other method names.

fix appraiser appraise method

remove unnecessary parameter and add view keyword

track initial debt in shelf contract

collectable loans shouldn't allow repay

mcd auction (flipper contract)

each new ERC20 for MCD has a individual gemJoin and flipper contract (auction).

Currently, we are using the default flipper contract.

We need to define the requirements for our auction contract. (Additional Whitelist etc)

create Bouncer contract

add simple lender contract

A simple lender contract should be added for use cases without a CVT token.

The simple lender contract should provide the pile with new currency tokens if a new nft gets locked.

review all contracts for auth and safe math

add bash script for additional admin

add pile file fee to admin contract

add short description and license to each file

Move interest calculation into a separate contract

• remove interest calculation from the pile
• create Interest contract
• keep loan chi values stored inside pile (could be used by other contracts)

create Operator contract

Add handling for defaulted loans

https://centrifuge.hackmd.io/CwncH44eTRyCJOKaZpc6bQ

##### AC

• As a pool operator I want to remove defaulted loans from my tinlake pool
• As a whitelisted collector I want to be able to buy out underlying assets from the default loans by repaying the outstanding debt
• As an admin I want to whitelist collectors
• As the owner of a defaulted loan I should not be able to repay the loan anymore & should see that my loan got collected in the UI

when is a loan considered defaulted?

• if the loan price is not matching the loan threshold it is considered defaulted
• assumption: for now pool admins/operators can modify loan prices

##### TC

Spotter

• detects collectable loans
• current implementation: same threshold for all loans
  optional: could manage individual loans (interface wouldn't change)

Tag

• know the default price for a collectable loans
• current implementation: default price for the loan == loan debt
  optional : could manage the auction prices

Pile

• remove defaulted loan
• adjust the loss value

Shelf

• allow to move collateral asset to the collector

Tranche Manager

• monitor loss changes of the pool

Collector

• ask spotter if a loan is collectable
• if collectable: asks tag for the default price
• remove defaulted loan from the pile
• move ownership of collateral asset from shelf to self
• functions:
  repayLoan()
  freeNFT()

Keeper
not implemented
would manage the access to the collector (whitelist or auction)

handle CDP liquidation scenarios

add functionality to cover CDP liquidation scenario

add loan owner check to shelf and pile

• add loan owner check to core contracts

• remove reception

• adjust integration tests

• desk.balance() can be public

create spec for manager contract

create spec for lender contract

create Admin wrapper contract for demo env

test pile edge cases

add more tests to pile for fee edge cases

create Quant contract

improve mock contracts with naming convention

Currently we are using different naming convention. For getting a method call counter

core contract separation

extend pile to work with fees and more unit tests

investigate: failed borrow on kovan with previous principal/appraisal=0

Setup:

three loans whitelisted loans with appraisal=0 and prinicipal=0 before the whitelisting with non zero values.

appraisal=0 and principal=0 is an edge case and results in a loan repaid state.

Investigate if the edge case caused a broken contract state for the following transactions.

next whitelisting with non zero values failed in the borrow transaction afterwards

See:
https://kovan.etherscan.io/tx/0xc5cac4169620ff8835c23f24820904e8f587f76aa3a4033e8d06f68670ceff61

Add unit tests for collector, tag, spotter

create TIN ERC20 contract

add siphon contract

The siphon contract should allow the admin to take out excess DAI

investigate: balance call in reception.borrow assumes lender.provide

after the appraisal of an NFT changes dynamically it could be the case that the desk.balance call in reception.borrow is trying to reduce it instead of providing more liquidity

Currently, it would fail because the pile doesn't have the needed currency.
In case the pile would own currency a reduce would be triggered.

The borrow transaction would fail because the pile would not receive extra liquidity.

add whitelist undo functionality

It should be possible to modify the defined principal and interest after the whitelisting happened by the admin.

Only the admin should be allowed to change the principal and the interest rate/

If the loan is already borrowed it should be not possible.

outstanding debt is not zero after all loans are repaid

Issue initially created in Tinlake UI.
centrifuge/tinlake-ui#51

create spec for drop token

create DROP ERC20 contract

Prevent Principal Amount to be larger than Appraisal on contract level

withdraw and repay not full principal amount

It should be possible for a borrower not withdraw the full principal and repay only parts of the loan.

add deploy script for backer

add collector contract

The collector contract should allow seizing of collateral that is overdue at a specified price

own repository for deploy scripts

add own repositories for deploy scripts.

Current deployments

• backer
• MCD

tests: add unit tests and mocks for the maker adapter

extend appraiser contract to use NFT registry

add linter to project

create TrancheManager contract