cbETH

cbETH is Coinbase's wrapped staked-ETH token.

cbETH is Coinbase's wrapped staked-ETH token. No direct cbETH/USD Chainlink feed is used; this ICustomPriceFeed adapter combines the token's own exchange rate with an ETH/USD price read from the NAV's own primary feed.

This feed is built and tested but deployed on no chain. Mainnet cbETH is not a held asset, so it is not registered on any NAV Calculator. cbETH is priced on Base, by the separate cbETH (L2) feed — a different composition, using a Chainlink cbETH/ETH market rate.

The contract is kept deliberately rather than deleted: it reads cbETH's own exchangeRate(), which is fundamental and therefore independent of the market feed the L2 variant composes — exactly the shape a divergence monitor needs, should mainnet cbETH ever be held.

The ETH/USD term is sourced from the NAV's own selector — see Base/USD from the NAV's own selector.

Source: cbETH_CustomPriceFeed.sol

Mainnet feed. The L2 deployments use a different oracle composition — see cbETH (L2).

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Approach

exchangeRate() × ETH/USD.

cbETH (Mainnet) price feed — how its oracle inputs compose into a USD price, with the staleness gate.

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Price calculation

price = exchangeRate() (18) × (ETH/USD) (8) / 1e18      // USD, 8 dec

Input	Source	Description
exchangeRate	IcbETH.exchangeRate() on cbETH (18 dec)	ETH per 1 cbETH
ETH/USD	NAV base — getPriceDataNoDivergence(WETH) (8 dec)	the NAV's primary WETH/USD price

exchangeRate() is read directly from the cbETH contract and grows as staking rewards accrue. Output decimals are inherited from the ETH/USD feed (8).

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Constructor

constructor(
    address cbEth_,
    address nav_,
    address baseAsset_
)

Parameter	Description
cbEth_	cbETH token address (also the supported underlying)
nav_	NAVCalculator (proxy) — supplies the base asset's USD price via getPriceDataNoDivergence
baseAsset_	The registered base asset whose USD price is read (WETH)

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Staleness

getLatestPrice() returns stale if exchangeRate() returns 0, or if the NAV reports the base asset (WETH) stale — all its feeds stale. The base leg's updatedAt comes from the NAV's selected WETH feed. The exchangeRate() call has no independent heartbeat.

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Chains

Deployed on Ethereum. For the Base deployment using a direct Chainlink cbETH/ETH feed, see cbETH (L2).