CorrelatedTokenOracle

CorrelatedTokenOracle in oracle v2.16.0 is the abstract base for current capped correlated-token oracles.

This is the V2 API. Older proxy implementations can use an uncapped V1 base with only the token, underlying, ResilientOracle, and price functions. Do not apply V2 selectors or storage assumptions until the exact deployed implementation has been identified.

Constructor and state

constructor(
    address correlatedToken,
    address underlyingToken,
    address resilientOracle,
    uint256 annualGrowthRate,
    uint256 snapshotInterval,
    uint256 initialSnapshotMaxExchangeRate,
    uint256 initialSnapshotTimestamp,
    address accessControlManager,
    uint256 snapshotGap
)

The V2 base exposes:

• immutable CORRELATED_TOKEN, UNDERLYING_TOKEN, RESILIENT_ORACLE, and ACCESS_CONTROL_MANAGER;
• mutable growthRatePerSecond, snapshotInterval, snapshotMaxExchangeRate, snapshotTimestamp, and snapshotGap.

annualGrowthRate is divided by 31,536,000 and uses 1e18 scaling. Growth and interval must either both be enabled or both be zero. When the interval is enabled, the initial maximum exchange rate and timestamp must be nonzero.

Pricing

function getUnderlyingAmount() public view virtual returns (uint256);
function getMaxAllowedExchangeRate() public view returns (uint256);
function getPrice(address asset) public view returns (uint256);
function isCapped() external view returns (bool);

Each derived oracle supplies the live amount of UNDERLYING_TOKEN for one CORRELATED_TOKEN. The base then multiplies that exchange rate by RESILIENT_ORACLE.getPrice(UNDERLYING_TOKEN) and normalizes by the correlated token’s decimals.

When the cap is enabled:

maximum rate = snapshot rate
             + snapshot rate × growth per second × elapsed seconds

priced rate = min(live exchange rate, maximum rate)

isCapped() reports whether the live exchange rate currently exceeds that maximum. When snapshotInterval == 0, capping is disabled.

Snapshot and growth controls

function setSnapshot(
    uint256 snapshotMaxExchangeRate,
    uint256 snapshotTimestamp
) external;

function setGrowthRate(
    uint256 annualGrowthRate,
    uint256 snapshotInterval
) external;

function setSnapshotGap(uint256 snapshotGap) external;

These three setters are authorized by ACCESS_CONTROL_MANAGER using their exact function signatures.

function updateSnapshot() public;

updateSnapshot is permissionless. It is a no-op until the interval has elapsed or when capping is disabled. On update, it stores min(live rate, current maximum) + snapshotGap, advances the timestamp, and asks the ResilientOracle to update the underlying asset price.

The cap limits exchange-rate growth; it does not validate the underlying USD oracle. Both the derived exchange-rate source and the configured underlying price route remain security dependencies.