> For the complete documentation index, see [llms.txt](https://docs.kpk.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.kpk.io/funds/infrastructure/onchain-accounting/price-feeds/ezeth.md).
# ezETH
ezETH is Renzo's liquid restaked ETH token. No direct ezETH/USD Chainlink feed exists on mainnet, so this `ICustomPriceFeed` adapter derives the backing ratio from Renzo's protocol TVL and the ezETH supply, then converts to USD using the NAV's primary ETH/USD price. An independent [cross-rate](/funds/infrastructure/onchain-accounting/price-feeds/cross-rate.md) **monitor** feed (`ETH/USD × ezETH/ETH`) is registered as a [divergence monitor](/funds/infrastructure/onchain-accounting/price-feeds.md#primary-feed-and-divergence-monitors) — if its ezETH rate diverges from Renzo's on-chain rate beyond tolerance, ezETH is flagged `irregular` without moving its price.
{% hint style="info" %}
**ezETH has two monitors, and only one of them is a market feed.** One cross-rate monitor's rate leg is RedStone's multi-feed **`ezETH_FUNDAMENTAL`**. Against a fundamental primary that puts *both* sides of the comparison on fundamentals, so it catches a reporting fault between two independent computations of the same claim but **not** a market depeg — the thing the tolerance exists to detect.
The second cross-rate monitor carries a genuine **market** leg, which is what makes the tolerance meaningful. Because `divergenceBps` is taken against the **worst** single monitor rather than the median, the market monitor dominates instead of being diluted by the fundamental one sitting near 0 bps, so ezETH's 250 bps tolerance can fire.
The market feed is itself deprecated by RedStone, which is deliberate and bounded: a monitor can never price NAV, and monitors are heartbeat-gated, so a frozen feed **self-excludes** from the divergence check rather than contributing a stale rate — `monitorFeedCount` simply drops from 2 to 1, making the degradation observable. Its heartbeat is derived from that feed's own measured cadence rather than copied from the other monitor's. Should *both* monitors go unreadable, ezETH is reported in [`NAV.monitorsUnhealthyPriceAssets`](/funds/infrastructure/onchain-accounting/concepts/stale-prices-and-sequencer.md#when-no-monitor-answered-monitorsunhealthypriceassets), so the loss of the check is visible rather than presenting as a clean `irregular` flag.
Its pair identity is **not** assertable from the feed contract: RedStone Classic-Push feeds return the constant `"Redstone Price Feed"` from `description()`, carrying no pair information, so the [rate-feed guard](/funds/infrastructure/onchain-accounting/price-feeds.md#custom-price-feeds) declares this leg `$UNVERIFIABLE` with a written reason and holds it to the plausibility band and readability checks instead.
{% endhint %}
**Source:** [`ezETH_CustomPriceFeed.sol`](https://github.com/karpatkey/onchain-accounting/blob/main/src/prices/protocols/ezETH_CustomPriceFeed.sol)
{% hint style="info" %}
**Mainnet feed.** The L2 deployments use a different oracle composition — see [ezETH (L2)](/funds/infrastructure/onchain-accounting/price-feeds/ezeth-l2.md).
{% endhint %}
***
## Approach
`calculateTVLs().totalTVL ÷ totalSupply` (ezETH/ETH) × ETH/USD.
ezETH (Mainnet) price feed — how its oracle inputs compose into a USD price, with the staleness gate.
{% hint style="info" %}
The ETH/USD term is sourced from the NAV's own selector — see [Base/USD from the NAV's own selector](/funds/infrastructure/onchain-accounting/price-feeds.md#base-usd-from-the-navs-own-selector).
{% endhint %}
***
## Price calculation
```
ezEthRate = totalTVL (18) × 1e18 / ezETH.totalSupply() // ezETH/ETH, 18 dec
price = ezEthRate (18) × (ETH/USD) (8) / 1e18 // USD, 8 dec
```
| Input | Source | Description |
| ------------- | ------------------------------------------------------- | ----------------------------------------------------------------- |
| `totalTVL` | `IRestakeManager.calculateTVLs()` (18 dec) | Total ETH value restaked via Renzo (read defensively — see below) |
| `totalSupply` | `IERC20(ezETH).totalSupply()` | Circulating ezETH supply |
| ETH/USD | **NAV base** — `getPriceDataNoDivergence(WETH)` (8 dec) | the NAV's primary WETH/USD price |
The rate is taken directly from Renzo protocol state rather than a market price. If `calculateTVLs()` cannot be read or `totalSupply()` is `0`, the feed is marked stale. Output decimals are inherited from the ETH/USD feed (8).
Only the **third** return value of `calculateTVLs()` — `totalTVL`, a plain `uint256` — is read; the two nested arrays it also returns are never decoded. That matters because `try`/`catch` does not intercept a return-data **decode** failure (the decode runs in the calling frame, after the call returns), and a nested `uint256[][]` is the most failure-prone shape to decode: a bad head offset or an absurd length would propagate past the `catch` and revert the feed instead of degrading to stale.
***
## Constructor
```solidity
constructor(
address ezEth_,
address restakeManager_,
address nav_,
address baseAsset_
)
```
| Parameter | Description |
| ----------------- | ------------------------------------------------------------------------------------------ |
| `ezEth_` | ezETH token address (also the supported underlying) |
| `restakeManager_` | Renzo RestakeManager (exposes `calculateTVLs()`) |
| `nav_` | NAVCalculator (proxy) — supplies the base asset's USD price via `getPriceDataNoDivergence` |
| `baseAsset_` | the registered base asset whose USD price is read (WETH) |
***
## Staleness
`getLatestPrice()` returns stale if `calculateTVLs()` reverts, if `totalSupply()` is `0`, or if the derived rate is `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.
{% hint style="warning" %}
`calculateTVLs()` reads Renzo's internal oracles, whose freshness is **not** independently checked here — only the NAV's base-asset staleness is. If Renzo's oracles are stale the TVL figure may be stale undetected. This is an architectural constraint of Renzo on mainnet; the L2 adapter avoids it by reading `xRenzoDeposit.getRate()` directly.
{% endhint %}
***
## Chains
Deployed on **Ethereum**. For the rollup deployment, see [ezETH (L2)](/funds/infrastructure/onchain-accounting/price-feeds/ezeth-l2.md).
---
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