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Linear Discount Oracle Wrapper

Sources:

Overview​

PendleLinearDiscountOracleWrapper is a thin stateless wrapper that fixes the one incompatibility between Pendle's deterministic oracles and Chainlink-consuming protocols: the updatedAt field.

Pendle's deterministic oracles (PendleSparkLinearDiscountOracle, PendleLpLinearDiscountOracle) return updatedAt = 0 in latestRoundData() because their prices are computed entirely from block.timestamp and immutable constructor parameters — they are never "stale" by design. However, most lending protocols enforce a staleness check of the form block.timestamp - updatedAt < threshold, which will reject any feed that returns updatedAt = 0.

The wrapper solves this by forwarding all fields from the inner oracle unchanged, except updatedAt, which it overwrites with block.timestamp.

When to Use the Wrapper​

Does your protocol check updatedAt staleness?

  • No — Deploy PendleSparkLinearDiscountOracle directly via PendleSparkLinearDiscountOracleFactory.
  • Yes (most lending protocols) — Deploy via PendleSparkLinearDiscountOracleFactoryWrapper. The wrapper always returns updatedAt = block.timestamp, satisfying any staleness threshold.
  • You already have a bare oracle — Call PendleSparkLinearDiscountOracleFactoryWrapper.wrap(existingOracle) to add the wrapper without redeploying.
LP oracle has no factory wrapper

PendleLpLinearDiscountOracle does not have a dedicated factory wrapper contract. To apply the wrapper to an LP oracle, deploy PendleLpLinearDiscountOracle via PendleLpLinearDiscountOracleFactory, then wrap the deployed address manually:

address lpOracle   = lpFactory.create(market, baseLpDiscountPerYear, lpMaturedPrice);
address lpWrapped  = address(new PendleLinearDiscountOracleWrapper(lpOracle));

PendleLinearDiscountOracleWrapper​

A minimal proxy that wraps any IPChainlinkOracleEssential-compatible oracle and replaces its updatedAt with block.timestamp.

contract PendleLinearDiscountOracleWrapper is IPChainlinkOracleEssential {
    IPChainlinkOracleEssential public immutable innerOracle;

    constructor(address _innerOracle);
}

latestRoundData​

function latestRoundData()
    external
    view
    returns (
        uint80  roundId,
        int256  answer,
        uint256 startedAt,
        uint256 updatedAt,      // overwritten to block.timestamp
        uint80  answeredInRound
    );

All fields are forwarded from innerOracle.latestRoundData(), except updatedAt which is replaced with block.timestamp. The answer (the discount factor or LP price) is not modified in any way.

decimals​

function decimals() external view returns (uint8);

Delegates directly to innerOracle.decimals(). Returns 18 for all Pendle deterministic oracles.

PendleSparkLinearDiscountOracleFactoryWrapper​

A convenience contract that combines PendleSparkLinearDiscountOracleFactory and PendleLinearDiscountOracleWrapper into a single deployment step. Calling createWithPt or createWithMarket on this contract:

  1. Deploys a PendleSparkLinearDiscountOracle (via the inner factory)
  2. Immediately wraps it in PendleLinearDiscountOracleWrapper
  3. Returns the wrapper address — the address your protocol should point at

Emits WrapperOracleCreated(address indexed innerOracle, address indexed wrapper) on each deployment.

contract PendleSparkLinearDiscountOracleFactoryWrapper {
    PendleSparkLinearDiscountOracleFactory public immutable innerFactory;

    constructor(address _innerFactory);
}

createWithPt​

function createWithPt(
    address pt,
    uint256 baseDiscountPerYear
) external returns (address wrapper);

Deploys a PendleSparkLinearDiscountOracle for the given PT address, then wraps it. Returns the wrapper address.

createWithMarket​

function createWithMarket(
    address market,
    uint256 baseDiscountPerYear
) external returns (address wrapper);

Derives the PT address from IPMarket(market).readTokens(), then proceeds identically to createWithPt.

wrap​

function wrap(address innerOracle) public returns (address wrapper);

Wraps an already-deployed IPChainlinkOracleEssential-compatible oracle in a new PendleLinearDiscountOracleWrapper. Useful if you deployed an oracle via PendleSparkLinearDiscountOracleFactory directly and need to add the wrapper afterwards.

Deployment addresses: Find the factory wrapper address for each chain under "sparkLinearDiscountOracleFactoryWrapper" in the Deployments on GitHub.

Further Reading​

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