USDM is a stablecoin designed to maintain a 1 USD valuation backed by short-term US Treasury bills. The yield generated by these T-bills is automatically distributed to USDM token holders through rebasing. This feature keeps the price of USDM stable while steadily increasing the balance of USDM for token holders.
Mountain Protocol hosts the primary market that establishes the price peg. KYC-verified users can deposit collateral, either USDC or fiat currency, on our platform. In exchange, they receive USDM and can choose to redeem USDM for collateral or withdraw USDM to any Ethereum address. Since Mountain Protocol offers an exchange rate of one dollar per USDM in both directions, any price movement in the external (secondary) market can be traded in the primary market to re-establish the peg.
USDM is a rebasing ERC-20 token with a set of additional features, including pausing, blocking/unblocking accounts, role-based access control, and upgradability. The contract’s primary objective is to reflect the T-bills’ annual percentage yield (APY) within the token’s value. It achieves this through a reward multiplier rebasing mechanism, where the addRewardMultiplier function is called daily to adjust the reward multiplier, guaranteeing an accurate representation of yield from the underlying assets.
Acknowledging the complexities of handling rebasing tokens in the DeFi ecosystem, the wUSDM contract serves as a wrapped token, simplifying integration while preserving stability. The wUSDM contract is an ERC-462 token vault, enabling users to deposit USDM in exchange for wUSDM tokens. The USDM tokens are rebasing, whereas the wUSDM tokens are non-rebasing, making wUSDM ideal for seamless integration with protocols in the DeFi ecosystem.
The wUSDM contract incorporates the ERC-2612 permit functionality, allowing the use of signatures to grant token allowances. Additionally, the close relationship between the wUSDM and USDM contracts is also worth noting; the wUSDM contract leverages the account block list from the USDM contract to govern transfers and, specifically, prevent transfers from accounts included in the block list.
Finally, the wUSDM token transfers can be paused in two ways: either by being paused directly from within the wUSDM contract or in the event the USDM contract is paused.
The Mountain Protocol Security Center contains more details about the secure development process.
The security policy is detailed in SECURITY.md, and specifies how you can report security vulnerabilities and which versions will receive security updates. We run a bug bounty program on Immunefi to reward the responsible disclosure of vulnerabilities.
Audits can be found at https://github.com/mountainprotocol/audits.
Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.
Please make sure to run the linter and update tests as appropriate.
This Project uses Hardhat. It includes a contract, its tests, and a script that deploys the contract.
Prerequisites: Node v18 LTS
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Install dependencies
npm i
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Copy ENV file
cp .env.example .env
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Replace ENV variables with the values as needed
Try running some of the following tasks:
Testing
npm run testCoverage
npm run coverageLinter
npm run lintRunning local node
npx hardhat nodeCompile
npx hardhat compileDeploying and contract verification
npx hardhat run scripts/deploy.ts --network goerli
npx hardhat verify --network goerli <contract-address>Help
npx hardhat help- Access Control
- Rebasing token mechanism
- Minting and burning functionality
- Block/Unblock accounts
- Pausing emergency stop mechanism
- Reward multiplier system
- EIP-2612 permit support
- OpenZeppelin UUPS upgrade pattern
initialize(string memory name_, string memory symbol_, address owner): Initializes the contract.name(): Returns the name of the token.symbol(): Returns the symbol of the token.decimals(): Returns the number of decimals the token uses.convertToShares(uint256 amount): Converts an amount of tokens to shares.convertToTokens(uint256 shares): Converts an amount of shares to tokens.totalShares(): Returns the total amount of shares.totalSupply(): Returns the total supply.balanceOf(address account): Returns the account blanace.sharesOf(address account): Returns the account shares.mint(address to, uint256 amount): Creates new tokens to the specified address.burn(address from, uint256 amount): Destroys tokens from the specified address.transfer(address to, uint256 amount): Transfers tokens between addresses.blockAccounts(address[] addresses): Blocks multiple accounts at once.unblockAccounts(address[] addresses): Unblocks multiple accounts at once.isBlocked(address account): Checks if an account is blocked.pause(): Pauses the contract, halting token transfers.unpause(): Unpauses the contract, allowing token transfers.setRewardMultiplier(uint256 _rewardMultiplier): Sets the reward multiplier.addRewardMultiplier(uint256 _rewardMultiplierIncrement): Adds the given amount to the current reward multiplier.approve(address spender, uint256 amount): Approves an allowance for a spender.allowance(address owner, address spender): Returns the allowance for a spender.transferFrom(address from, address to, uint256 amount): Moves tokens from an address to another one using the allowance mechanism.increaseAllowance(address spender, uint256 addedValue): Increases the allowance granted to spender by the caller.decreaseAllowance(address spender, uint256 subtractedValue): Decreases the allowance granted to spender by the caller.DOMAIN_SEPARATOR(): Returns the EIP-712 domain separator.nonces(address owner): Returns the nonce for the specified address.permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s): Implements EIP-2612 permit functionality.
_authorizeUpgrade(address newImplementation): Internal function to authorize an upgrade._mint(address to, uint256 amount): Internal function to mint tokens to the specified address._burn(address account, uint256 amount): Internal function to burn tokens from the specified address._beforeTokenTransfer(address from, address to, uint256 amount): Hook that is called before any transfer of tokens._afterTokenTransfer(address from, address to, uint256 amount): Hook that is called after any transfer of tokens._transfer(address from, address to, uint256 amount): Internal function to transfer tokens between addresses._blockAccount(address account): Internal function to block account._unblockAccount(address account): Internal function to unblock an account._setRewardMultiplier(uint256 _rewardMultiplier): Internal function to set the reward multiplier._spendAllowance(address owner, address spender, uint256 amount): Internal function to spend an allowance._useNonce(address owner): Increments and returns the current nonce for a given address._approve(address owner, address spender, uint256 amount): Internal function to approve an allowance for a spender.
Transfer(from indexed addr, to uint256, amount uint256): Emitted when transferring tokens.RewardMultiplier(uint256 indexed value): Emitted when the reward multiplier has changed.Approval(address indexed owner, address indexed spender, uint256 value): Emitted when the allowance of a spender for an owner is set.AccountBlocked(address indexed addr): Emitted when an address is blocked.AccountUnblocked(address indexed addr): Emitted when an address is removed from the blocklist.Paused(address account): Emitted when the pause is triggered by account.Unpaused(address account): Emitted when the unpause is triggered by account.Upgraded(address indexed implementation): Emitted when the implementation is upgraded.
DEFAULT_ADMIN_ROLE: Grants the ability to grant roles.MINTER_ROLE: Grants the ability to mint tokens.BURNER_ROLE: Grants the ability to burn tokens.BLOCKLIST_ROLE: Grants the ability to manage the blocklist.ORACLE_ROLE: Grants the ability to update the reward multiplier.UPGRADE_ROLE: Grants the ability to upgrade the contract.PAUSE_ROLE: Grants the ability to pause/unpause the contract.
initialize(IUSDM _USDM, address owner): Initializes the contract.pause(): Pauses the contract, halting token transfers.unpause(): Unpauses the contract, allowing token transfers.paused(): Returns true if USDM or wUSDM is paused, and false otherwise.DOMAIN_SEPARATOR(): Returns the EIP-712 domain separator.nonces(address owner): Returns the nonce for the specified address.permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s): Implements EIP-2612 permit functionality.
_beforeTokenTransfer(address from, address to, uint256 amount): Hook that is called before any transfer of tokens._authorizeUpgrade(address newImplementation): Internal function to authorize an upgrade._useNonce(address owner): Increments and returns the current nonce for a given address.
Transfer(from indexed addr, to uint256, amount uint256): Emitted when transferring tokens.Approval(address indexed owner, address indexed spender, uint256 value): Emitted when the allowance of a spender for an owner is set.Paused(address account): Emitted when the pause is triggered by account.Unpaused(address account): Emitted when the unpause is triggered by account.Upgraded(address indexed implementation): Emitted when the implementation is upgraded.
DEFAULT_ADMIN_ROLE: Grants the ability to grant roles.UPGRADE_ROLE: Grants the ability to upgrade the contract.PAUSE_ROLE: Grants the ability to pause/unpause the contract.
Mountain Protocol Contracts are released under the MIT License.
The use of this Project is governed by the terms found at https://docs.mountainprotocol.com/legal/terms-and-conditions.