feat: multi-index refactor (shared AssetRegistry, per-vault curated constituents)

README.md

@@ -77,9 +77,9 @@ This is a research-stage codebase. It is not audited and it is not deployed. The
 
 ```
 src/
-  IndexVault.sol              ERC-7540 two-lane vault, NAV, settlement
+  IndexVault.sol              ERC-7540 two-lane vault, NAV, settlement, curated constituents
   PendingSilo.sol             isolated holder of in-flight value
-  ComponentRegistry.sol       constituents and health-checked Chainlink feeds
+  AssetRegistry.sol           shared asset catalog and health-checked Chainlink feeds
   methodology/
     MarketCapMethodology.sol  float-adjusted capped market-cap weighting
   libraries/

src/AssetRegistry.sol

@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.28;
+
+import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
+import { Ownable2Step } from "@openzeppelin/contracts/access/Ownable2Step.sol";
+import { IERC20Metadata } from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
+
+/// @notice Chainlink aggregator surface the registry consumes.
+interface IAggregatorV3 {
+    function decimals() external view returns (uint8);
+    function latestRoundData()
+        external
+        view
+        returns (uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound);
+}
+
+// ============================================================================
+// Errors
+// ============================================================================
+
+/// @notice Thrown when a constructor or setter receives the zero address.
+error AssetRegistry_ZeroAddress();
+
+/// @notice Thrown when registering an asset that is already registered.
+error AssetRegistry_AlreadyRegistered(address token);
+
+/// @notice Thrown when querying or removing an asset that is not registered.
+error AssetRegistry_NotRegistered(address token);
+
+/// @notice Thrown when registering beyond the catalog cap.
+error AssetRegistry_MaxAssetsReached();
+
+/// @notice Thrown when a heartbeat of zero is supplied.
+error AssetRegistry_ZeroHeartbeat();
+
+/// @notice Thrown when a feed reports a non-positive answer.
+error AssetRegistry_InvalidPrice(address feed, int256 answer);
+
+/// @notice Thrown when a feed has not updated within its heartbeat.
+error AssetRegistry_StalePrice(address feed, uint256 updatedAt, uint256 heartbeat);
+
+/// @notice Thrown when the USDC feed has not been configured.
+error AssetRegistry_UsdcFeedNotSet();
+
+/**
+ * @title AssetRegistry
+ * @notice Shared global catalog of registerable assets and their Chainlink USD
+ * price feeds. This is the eligible universe an index can draw from; it is not
+ * itself an index. A token is registered here once, and any index vault may
+ * then include it in its own curated constituent set. Membership lives in the
+ * vault, asset metadata lives here.
+ *
+ * Each asset carries a per-feed heartbeat rather than a single global staleness
+ * bound, and every price read is health-checked: a stale or non-positive answer
+ * reverts so that price-sensitive vault operations (mint, settle, rebalance)
+ * fail closed instead of transacting on bad data.
+ * @dev Prices are normalized to 8 decimals regardless of feed decimals.
+ * Supply-oracle source bindings can be attached per asset later.
+ */
+contract AssetRegistry is Ownable2Step {
+    struct Asset {
+        address token;
+        address feed;
+        uint48 heartbeat;
+        uint8 tokenDecimals;
+        uint8 feedDecimals;
+    }
+
+    /// @notice Normalized price precision for all reads (Chainlink USD standard).
+    uint8 public constant PRICE_DECIMALS = 8;
+
+    /// @notice Cap on the catalog size, distinct from any one index's size cap.
+    /// An index picks a subset of the catalog and applies its own size cap.
+    uint256 public constant MAX_ASSETS = 250;
+
+    /// @dev Registered assets in registration order.
+    address[] private _assetList;
+
+    /// @dev Asset data keyed by token address.
+    mapping(address token => Asset) private _assets;
+
+    /// @dev USDC is the settlement asset, priced through its own feed, never a basket constituent.
+    Asset private _usdc;
+
+    event AssetRegistered(address indexed token, address indexed feed, uint48 heartbeat);
+    event AssetRemoved(address indexed token);
+    event UsdcFeedSet(address indexed usdc, address indexed feed, uint48 heartbeat);
+
+    constructor(address initialOwner) Ownable(initialOwner) { }
+
+    // ========================================================================
+    // Admin
+    // ========================================================================
+
+    /// @notice Registers an asset with its Chainlink USD feed, adding it to the catalog.
+    /// @param token The ERC-20 asset address.
+    /// @param feed The Chainlink aggregator for the token's USD price.
+    /// @param heartbeat Maximum tolerated seconds since the feed's last update.
+    function registerAsset(address token, address feed, uint48 heartbeat) external onlyOwner {
+        if (token == address(0) || feed == address(0)) revert AssetRegistry_ZeroAddress();
+        if (heartbeat == 0) revert AssetRegistry_ZeroHeartbeat();
+        if (_assets[token].token != address(0)) revert AssetRegistry_AlreadyRegistered(token);
+        if (_assetList.length >= MAX_ASSETS) revert AssetRegistry_MaxAssetsReached();
+
+        _assets[token] = Asset({
+            token: token,
+            feed: feed,
+            heartbeat: heartbeat,
+            tokenDecimals: IERC20Metadata(token).decimals(),
+            feedDecimals: IAggregatorV3(feed).decimals()
+        });
+        _assetList.push(token);
+
+        emit AssetRegistered(token, feed, heartbeat);
+    }
+
+    /// @notice Removes an asset from the catalog.
+    /// @dev An index vault may still list a removed asset as a constituent; the
+    /// vault's own constituent governance handles forced exit of the position.
+    /// Removal here only stops the asset being newly includable and priced.
+    function removeAsset(address token) external onlyOwner {
+        if (_assets[token].token == address(0)) revert AssetRegistry_NotRegistered(token);
+
+        uint256 len = _assetList.length;
+        for (uint256 i = 0; i < len; i++) {
+            if (_assetList[i] == token) {
+                _assetList[i] = _assetList[len - 1];
+                _assetList.pop();
+                break;
+            }
+        }
+        delete _assets[token];
+
+        emit AssetRemoved(token);
+    }
+
+    /// @notice Configures the settlement-asset (USDC) price feed.
+    function setUsdcFeed(address usdc, address feed, uint48 heartbeat) external onlyOwner {
+        if (usdc == address(0) || feed == address(0)) revert AssetRegistry_ZeroAddress();
+        if (heartbeat == 0) revert AssetRegistry_ZeroHeartbeat();
+
+        _usdc = Asset({
+            token: usdc,
+            feed: feed,
+            heartbeat: heartbeat,
+            tokenDecimals: IERC20Metadata(usdc).decimals(),
+            feedDecimals: IAggregatorV3(feed).decimals()
+        });
+
+        emit UsdcFeedSet(usdc, feed, heartbeat);
+    }
+
+    // ========================================================================
+    // Views
+    // ========================================================================
+
+    /// @notice Returns the entire catalog of registered assets.
+    function getAssets() external view returns (Asset[] memory assets) {
+        uint256 len = _assetList.length;
+        assets = new Asset[](len);
+        for (uint256 i = 0; i < len; i++) {
+            assets[i] = _assets[_assetList[i]];
+        }
+    }
+
+    /// @notice Returns a single asset record.
+    function getAsset(address token) external view returns (Asset memory) {
+        Asset memory a = _assets[token];
+        if (a.token == address(0)) revert AssetRegistry_NotRegistered(token);
+        return a;
+    }
+
+    /// @notice Number of registered assets in the catalog.
+    function assetCount() external view returns (uint256) {
+        return _assetList.length;
+    }
+
+    /// @notice Whether `token` is a registered asset.
+    function isRegistered(address token) external view returns (bool) {
+        return _assets[token].token != address(0);
+    }
+
+    /// @notice Health-checked USD price of a registered asset, normalized to 8 decimals.
+    function getPriceUsd(address token) external view returns (uint256) {
+        Asset memory a = _assets[token];
+        if (a.token == address(0)) revert AssetRegistry_NotRegistered(token);
+        return _readFeed(a);
+    }
+
+    /// @notice Health-checked USD price of the settlement asset, normalized to 8 decimals.
+    function getUsdcPriceUsd() external view returns (uint256) {
+        Asset memory a = _usdc;
+        if (a.token == address(0)) revert AssetRegistry_UsdcFeedNotSet();
+        return _readFeed(a);
+    }
+
+    // ========================================================================
+    // Internal
+    // ========================================================================
+
+    /// @dev Reads a feed, enforces answer and staleness health, normalizes to 8 decimals.
+    function _readFeed(Asset memory a) internal view returns (uint256) {
+        (, int256 answer,, uint256 updatedAt,) = IAggregatorV3(a.feed).latestRoundData();
+        if (answer <= 0) revert AssetRegistry_InvalidPrice(a.feed, answer);
+        if (block.timestamp > updatedAt + a.heartbeat) {
+            revert AssetRegistry_StalePrice(a.feed, updatedAt, a.heartbeat);
+        }
+
+        uint256 price = uint256(answer);
+        if (a.feedDecimals == PRICE_DECIMALS) return price;
+        if (a.feedDecimals < PRICE_DECIMALS) return price * 10 ** (PRICE_DECIMALS - a.feedDecimals);
+        return price / 10 ** (a.feedDecimals - PRICE_DECIMALS);
+    }
+}