Timeless

Timeless is a yield tokenization protocol that offers Perpetual Yield Tokens (PYTs), which give their holders a perpetual right to claim the yield generated by the underlying principal. Timeless also offers Negative Yield Tokens (NYTs), a protocol-native way to short yield rates.

1 perpetual yield token represents the right to claim the yield generated by 1 underlying token from now to forever in the future.

Overview

1. Deposit x underlying tokens (e.g. DAI), receive x perpetual yield tokens and x negative yield tokens.
2. The DAI is deposited into yield protocols like Yearn.
3. A holder of x PYTs can claim the yield earned by x DAI since the last claim at any time.
4. In order to redeem x DAI from the protocol, one must burn x PYT and x NYT together.

Architecture

• Gate.sol: Abstract contract that mints/burns NYTs and PYTs of vaults of a specific protocol. Allows PYT holders to claim the yield earned by PYTs. Owns all vault shares.
• Factory.sol: Deploys NYT and PYT contracts. Tracks protocol fee info.
• NegativeYieldToken.sol: ERC20 token for representing NYTs.
• PerpetualYieldToken.sol: ERC20 token for representing PYTs.
• external/: Interfaces for external contracts Timeless interacts with.
  • IxPYT.sol: Interface for xPYT vaults.
  • YearnVault.sol: Interface for Yearn v2 vaults.
• gates/: Implementations of Gate integrated with different yield protocols.
  • ERC20Gate.sol: Abstract implementation of Gate for protocols using ERC20 vault shares.
  • YearnGate.sol: Implementation of Gate that uses Yearn v2 vaults.
  • ERC4626Gate.sol: Implementation of Gate that uses ERC4626 vaults.
• lib/: Libraries used by other contracts.
  • BaseERC20.sol: The basic gate-controlled ERC20 class used by PerpetualYieldToken and NegativeYieldToken.
  • FullMath.sol: Math library preventing phantom overflows during mulDiv operations.
  • Multicall.sol: Enables calling multiple methods in a single call to the contract.
  • SelfPermit.sol: Functionality to call permit on any EIP-2612-compliant token.

Installation

To install with DappTools:

dapp install timeless-fi/timeless

To install with Foundry:

forge install timeless-fi/timeless

Local development

This project uses Foundry as the development framework.

Dependencies

make install

Compilation

make build

Testing

make test