YieldToken
YieldToken is an implementation of zero-coupon Dai bonds. It is inspired by the paper "The Yield Protocol: On-Chain Lending With Interest Rate Discovery" by Dan Robinson and Allan Niemerg.
These smart contracts have been deployed to Kovan and the Mainnet, and a web frontend is deployed at http://app.yield.is
Detailed documentation can be found in the Yield docs.
Warning
This code is provided as-is, with no guarantees of any kind.
Install
Pre Requisites
Before running any command, make sure to install dependencies:
$ yarn
Lint Solidity
Lint the Solidity code:
$ yarn lint:sol
Lint TypeScript
Lint the TypeScript code:
$ yarn lint:ts
Coverage
Generate the code coverage report:
$ yarn coverage
Test
Compile and test the smart contracts with Buidler and Mocha:
$ yarn test
Fuzz
You will need to install echidna separately, and then run:
$ echidna-test . --contract WhitepaperInvariant --config contracts/invariants/config.yaml
Start a local blockchain
We use ganache as a local blockchain:
$ yarn ganache
Start a local copy of the mainnet blockchain
We use ganache to fork the mainnet blockchain:
$ yarn mainnet-ganache
Migrate
We use truffle for migrations, make sure that truffle-config.js suits your use case, start a local ganache instance as explained above, and then run truffle:
$ npx truffle migrate
or
$ npx truffle migrate --network mainnet-ganache
Math
In developing fyDai we have used two different libraries for fixed point arithmetic.
- For general use we have used a decimal-based fixed point math library, trading off performance for clarity.
- For heavy-duty use in the YieldSpace formula, we have used a binary-based fixed point math library, trading off clarity for performance.
Security
In developing the code in this repository we have set the highest bar possible for security. We have been fully audited by Trail of Bits, with the results publicly available. We have also used fuzzing tests for the Pool and YieldMath contracts, allowing us to find edge cases and vulnerabilities that we would have missed otherwise.
Bug Bounty
Yield is offering bounties for bugs disclosed to us at security@yield.is. The bounty reward is up to $25,000, depending on severity. Please include full details of the vulnerability and steps/code to reproduce. We ask that you permit us time to review and remediate any findings before public disclosure.
Contributing
This project doesn't include any governance or upgradability features. If you have a contribution to make, please reach us out on Discord and we will consider it for a future release or product.
Acknowledgements
We would like to thank Dan Robinson (Paradigm), Georgios Konstantopoulos (Paradigm), Sam Sun (Paradigm), Mikhail Vladimirov (ABDK), Gustavo Grieco (Trail of Bits), Martin Lundfall (dAppHub) and Noah Zinsmeister (Uniswap) for their feedback and advice. We wouldn't be here without them.
License
All files in this repository are released under the GPLv3 license.