> 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/weeth-l2.md).

# weETH (L2)

Custom price feed for **ether.fi Wrapped eETH** on L2 chains. No direct weETH/USD feed exists, so the price is composed from a Chainlink weETH/eETH feed and a Chainlink ETH/USD feed, treating eETH ≈ ETH at 1:1.

**Source:** [`weETH_L2_CustomPriceFeed.sol`](https://github.com/karpatkey/onchain-accounting/blob/main/src/prices/protocols/weETH_L2_CustomPriceFeed.sol)

{% hint style="info" %}
**L2 feed.** For the Ethereum mainnet feed, see [weETH](/funds/infrastructure/onchain-accounting/price-feeds/weeth.md).
{% endhint %}

***

## Approach

Chainlink weETH/eETH × ETH/USD *(eETH treated as 1:1 with ETH)* — the ETH/USD term is read from the NAV's own primary feed via `getPriceData(WETH)`, not a hardcoded oracle.

<figure><img src="/files/h782TJcT1pQtuKqwA6fF" alt="Left-to-right flowchart of the weETH (L2) price feed: rate and Chainlink inputs combine into a USD price, with a staleness gate."><figcaption><p>weETH (L2) price feed — how its oracle inputs compose into a USD price, with the staleness gate.</p></figcaption></figure>

{% 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

```
price = (weETH/eETH) × (ETH/USD, NAV-selected) / 10^(weETH/eETH decimals)
```

| Input        | Source                                                  | Description                      |
| ------------ | ------------------------------------------------------- | -------------------------------- |
| `weETH/eETH` | Chainlink weETH/eETH feed (`latestRoundData`)           | weETH price in eETH (18 dec)     |
| `ETH/USD`    | **NAV base** — `getPriceDataNoDivergence(WETH)` (8 dec) | the NAV's primary WETH/USD price |

The eETH/ETH peg is assumed to hold at 1:1; an eETH depeg would not be captured. The divisor is `10 ** RATE_FEED.decimals()`, captured once at construction as `_rateUnit`. Output is **8 decimals** (inherited from the ETH/USD feed).

***

## Constructor

```solidity
constructor(
    address weEth_,
    address weEthToEethChainlink_,
    uint256 weEthToEethHeartbeat_,
    address nav_,
    address baseAsset_
)
```

| Parameter               | Description                                                                                |
| ----------------------- | ------------------------------------------------------------------------------------------ |
| `weEth_`                | weETH token address (the supported underlying asset)                                       |
| `weEthToEethChainlink_` | Chainlink weETH/eETH aggregator                                                            |
| `weEthToEethHeartbeat_` | Staleness window (seconds) for the weETH/eETH feed                                         |
| `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 = true` if the weETH/eETH feed satisfies `block.timestamp − updatedAt ≥ heartbeat`, if its answer is `≤ 0`, if its `updatedAt` is in the future (clamped to `block.timestamp`), or if the NAV reports the base asset (WETH) stale — all its feeds stale. The base leg's `updatedAt` now comes from the NAV's selected WETH feed. The reported `updatedAt` is the **older** of the two legs.

***

## Chains

Deployed on **Arbitrum and Base**. The Ethereum mainnet counterpart is [weETH (Mainnet)](/funds/infrastructure/onchain-accounting/price-feeds/weeth.md), which uses the weETH/eETH rate against an eETH/USD composition.


---

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