psXDC rate oracle

For money markets and other integrators that want to price bridged psXDC on Base, Arbitrum, BNB Chain, or HyperEVM. psXDC is a yield-bearing vault share: its fair value is XDC price × psXDC/XDC exchange rate. This oracle publishes that exchange rate cross-chain from XDC so you can price psXDC exactly like a wstETH/rETH rate provider.

Interface

PsxdcRateOracle implements the Chainlink AggregatorV3Interface:

function decimals() external view returns (uint8);        // 18
function latestRoundData() external view returns (
    uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound
);
function isStale() external view returns (bool);          // true past the staleness window

answer = XDC redeemable per 1e18 psXDC (18 decimals). Compose it with your existing XDC/USD feed:

psXDC/USD = latestRoundData().answer * (XDC/USD) / 1e18

Safety guarantees

The rate can only be written by the wired XDC publisher (LayerZero peer auth, 2 required DVNs). Each update is additionally guarded on the destination:

• Monotonic — the rate cannot decrease (share price only grows). A rare validator-loss writedown requires an explicit, one-shot owner override, so a spurious downward push is rejected by default.
• Step-capped — each update may rise by at most maxStepBps (default 1%), blunting a bad or manipulated push.
• Staleness — updatedAt plus isStale() let you reject data older than the configured window: 8 days on all four chains (raised from 2 days on 2 Oct 2026). StakeXDC pushes the rate whenever it changes (the vault's rate moves in roughly monthly reward steps) and refreshes it at least weekly; the push is permissionless so it cannot be censored.

If pushes lapse long enough that legitimate cumulative growth would exceed the per-update step cap, the bridged update is rejected and the feed goes stale (safe: integrators see isStale() and pause) rather than jumping. The owner restores liveness with a break-glass adminSetRate, which still enforces non-zero and (unless explicitly armed) monotonicity — so it can never silently mark psXDC down.

Recommended usage

Treat the oracle as the exchange-rate leg only; keep your own market XDC/USD feed for the base asset. For collateral, apply your standard loan-to-value and liquidation parameters to the composed psXDC/USD price, and reject updates when isStale() is true.

Addresses

Per-chain oracle addresses are in Deployed Contracts & Addresses. Reach out at [email protected] for listing support.