feat: add Anzen USDz plugin

common/configuration.ts

@@ -115,6 +115,10 @@ export interface ITokens {
   // Mountain
   USDM?: string
   wUSDM?: string
+
+  // Anzen
+  USDZ?: string
+  sUSDz?: string
 }
 
 export type ITokensKeys = Array<keyof ITokens>
@@ -256,6 +260,8 @@ export const networkConfig: { [key: string]: INetworkConfig } = {
       sdUSDCUSDCPlus: '0x9bbF31E99F30c38a5003952206C31EEa77540BeF',
       USDe: '0x4c9edd5852cd905f086c759e8383e09bff1e68b3',
       sUSDe: '0x9D39A5DE30e57443BfF2A8307A4256c8797A3497',
+      USDz: '0xA469B7Ee9ee773642b3e93E842e5D9b5BaA10067',
+      sUSDz: '0x547213367cfB08ab418E7b54d7883b2C2AA27Fd7',
     },
     chainlinkFeeds: {
       RSR: '0x759bBC1be8F90eE6457C44abc7d443842a976d02',
@@ -513,6 +519,8 @@ export const networkConfig: { [key: string]: INetworkConfig } = {
       sUSDbC: '0x4c80e24119cfb836cdf0a6b53dc23f04f7e652ca',
       wstETH: '0xc1CBa3fCea344f92D9239c08C0568f6F2F0ee452',
       STG: '0xE3B53AF74a4BF62Ae5511055290838050bf764Df',
+      USDz: '0x04D5ddf5f3a8939889F11E97f8c4BB48317F1938',
+      sUSDz: '0xe31eE12bDFDD0573D634124611e85338e2cBF0cF',
     },
     chainlinkFeeds: {
       DAI: '0x591e79239a7d679378ec8c847e5038150364c78f', // 0.3%, 24hr
@@ -529,6 +537,8 @@ export const networkConfig: { [key: string]: INetworkConfig } = {
       stETHETH: '0xf586d0728a47229e747d824a939000Cf21dEF5A0', // 0.5%, 24h
       ETHUSD: '0x71041dddad3595F9CEd3DcCFBe3D1F4b0a16Bb70', // 0.15%, 20min
       wstETHstETH: '0xB88BAc61a4Ca37C43a3725912B1f472c9A5bc061', // 0.5%, 24h
+      USDz: '0xe25969e2Fa633a0C027fAB8F30Fc9C6A90D60B48', // 0.5%, 24hr
+      sUSDzUSDzexr: '0xD89c7fFB39C44b17EAecd8717a75A36c19C07582', // 0.5%, 24hr
     },
     GNOSIS_EASY_AUCTION: '0xb1875Feaeea32Bbb02DE83D81772e07E37A40f02', // mock
     COMET_REWARDS: '0x123964802e6ABabBE1Bc9547D72Ef1B69B00A6b1',

contracts/plugins/assets/anzen/L2USDzFiatCollateral.sol

@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: BlueOak-1.0.0
+pragma solidity 0.8.19;
+
+import "@openzeppelin/contracts/utils/math/Math.sol";
+import "../../../libraries/Fixed.sol";
+import "../AppreciatingFiatCollateral.sol";
+import "../OracleLib.sol";
+
+/**
+ * @title USDz Fiat Collateral for L2s (like Base)
+ * @notice Collateral plugin for USDz (Anzen Finance)
+ * tok = sUSDz  (wrapped USDz, ERC4626 vault on Ethereum Mainnet)
+ * ref = USDz
+ * tar = USD
+ * UoA = USD
+ */
+
+contract L2USDzFiatCollateral is AppreciatingFiatCollateral {
+    using OracleLib for AggregatorV3Interface;
+    using FixLib for uint192;
+
+    // Here we include them directly and ignore the parent class' chainlinkFeed entirely.
+
+    AggregatorV3Interface public immutable targetPerRefChainlinkFeed; // {tar/ref}
+    uint48 public immutable targetPerRefChainlinkTimeout; // {s}
+
+    AggregatorV3Interface public immutable refPerTokenChainlinkFeed; // {ref/tok}
+    uint48 public immutable refPerTokenChainlinkTimeout; // {s}
+
+    /// @param config.chainlinkFeed - ignored
+    /// @param config.oracleTimeout - ignored
+    /// @param config.oracleError {1} Should be the oracle error for UoA/tok
+    constructor(
+        CollateralConfig memory config,
+        uint192 revenueHiding,
+        AggregatorV3Interface _targetPerRefChainlinkFeed,
+        uint48 _targetPerRefChainlinkTimeout,
+        AggregatorV3Interface _refPerTokenChainlinkFeed,
+        uint48 _refPerTokenChainlinkTimeout
+    ) AppreciatingFiatCollateral(config, revenueHiding) {
+        require(config.defaultThreshold != 0, "defaultThreshold zero");
+
+        require(address(_targetPerRefChainlinkFeed) != address(0), "targetPerRefFeed missing");
+        require(_targetPerRefChainlinkTimeout != 0, "targetPerRefTimeout zero");
+        require(address(_refPerTokenChainlinkFeed) != address(0), "refPerTokenFeed missing");
+        require(_refPerTokenChainlinkTimeout != 0, "refPerTokenTimeout zero");
+
+        targetPerRefChainlinkFeed = _targetPerRefChainlinkFeed;
+        targetPerRefChainlinkTimeout = _targetPerRefChainlinkTimeout;
+
+        refPerTokenChainlinkFeed = _refPerTokenChainlinkFeed;
+        refPerTokenChainlinkTimeout = _refPerTokenChainlinkTimeout;
+        maxOracleTimeout = uint48(
+            Math.max(
+                Math.max(maxOracleTimeout, _targetPerRefChainlinkTimeout),
+                Math.max(maxOracleTimeout, _refPerTokenChainlinkTimeout)
+            )
+        );
+    }
+
+    /// Can revert, used by other contract functions in order to catch errors
+    /// @return low {UoA/tok} The low price estimate
+    /// @return high {UoA/tok} The high price estimate
+    /// @return pegPrice {target/ref} The actual price observed in the peg
+    function tryPrice()
+        external
+        view
+        override
+        returns (
+            uint192 low,
+            uint192 high,
+            uint192 pegPrice
+        )
+    {
+        // {tar/ref} Get current market peg ({eth/steth})
+        pegPrice = targetPerRefChainlinkFeed.price(targetPerRefChainlinkTimeout);
+
+        // {UoA/tok} = {tar/ref} * {ref/tok}
+        uint192 p = pegPrice.mul(underlyingRefPerTok());
+        uint192 err = p.mul(oracleError, CEIL);
+
+        high = p + err;
+        low = p - err;
+        // assert(low <= high); obviously true just by inspection
+    }
+
+    /// @return {ref/tok} Quantity of whole reference units per whole collateral tokens
+    function underlyingRefPerTok() public view override returns (uint192) {
+        return refPerTokenChainlinkFeed.price(refPerTokenChainlinkTimeout);
+    }
+}

contracts/plugins/assets/anzen/README.md

@@ -0,0 +1,33 @@
+# Anzen USDz Collateral Plugin
+
+## Summary
+
+`USDz` is a stablecoin backed by a diversified portfolio of private credit assets, specifically over-collateralized asset-backed securities. These assets are rigorously underwritten in partnership with Percent, a US licensed broker-dealer that has structured and serviced over $1.7 billion in credit deals since 2018. The protocol deploys capital alongside institutional fiat investors, ensuring a robust and secure backing for USDz.
+
+The diversified credit portfolio underlying USDz provides a consistent income stream that can support sustainable rewards emissions for `sUSDz(Staked USDz)`. This design allows USDz to be a reliable store of value based on its stable RWA backing, with the added benefit of consistent rewards emissions that are uncorrelated to crypto price movements.
+
+`sUSDz` is a high-yield ERC4626 vault, most similar to the DAI savings module. This plugin allows `sUSDz` holders to use their tokens as collateral in the Reserve Protocol.
+
+Since it is ERC4626, the redeemable USDz amount can be obtained by dividing `sUSDz.totalAssets()` by `sUSDz.totalSupply()`.
+
+`USDz` contract: 
+    - <https://etherscan.io/address/0xA469B7Ee9ee773642b3e93E842e5D9b5BaA10067#code>
+    - <https://basescan.org/address/0x04D5ddf5f3a8939889F11E97f8c4BB48317F1938#code>
+
+`sUSDz` contract:
+    - <https://etherscan.io/address/0x547213367cfb08ab418e7b54d7883b2c2aa27fd7#code>
+    - <https://basescan.org/address/0xe31ee12bdfdd0573d634124611e85338e2cbf0cf#code>
+
+## Implementation
+
+### Units
+
+| tok   | ref  | target | UoA |
+| ----- | ---- | ------ | --- |
+| sUSDz | USDz | USD    | USD |
+
+### Functions
+
+#### refPerTok {ref/tok}
+
+`return shiftl_toFix(erc4626.convertToAssets(oneShare), -refDecimals)`

contracts/plugins/assets/anzen/USDzFiatCollateral.sol

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: BlueOak-1.0.0
+pragma solidity 0.8.19;
+
+import { CollateralConfig } from "../AppreciatingFiatCollateral.sol";
+import { ERC4626FiatCollateral } from "../ERC4626FiatCollateral.sol";
+
+/**
+ * @title USDz Fiat Collateral
+ * @notice Collateral plugin for USDz (Anzen Finance)
+ * tok = sUSDz (ERC4626 vault)
+ * ref = USDz
+ * tar = USD
+ * UoA = USD
+ */
+
+contract USDzFiatCollateral is ERC4626FiatCollateral {
+    /// config.erc20 must be sUSDz
+    /// @param config.chainlinkFeed Feed units: {UoA/ref}
+    /// @param revenueHiding {1} A value like 1e-6 that represents the maximum refPerTok to hide
+    constructor(CollateralConfig memory config, uint192 revenueHiding)
+        ERC4626FiatCollateral(config, revenueHiding)
+    {
+        require(config.defaultThreshold != 0, "defaultThreshold zero");
+    }
+}