> 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/rseth-l2.md).

# rsETH (L2)

Custom price feed for **Kelp DAO rsETH** on L2 chains. No direct rsETH/USD feed exists, so the price is composed from a Chainlink rsETH/ETH feed and the NAV's primary ETH/USD price.

**Source:** [`rsETH_L2_CustomPriceFeed.sol`](https://github.com/karpatkey/onchain-accounting/blob/main/src/prices/protocols/rsETH_L2_CustomPriceFeed.sol)

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

***

## Approach

Chainlink rsETH/ETH × NAV primary ETH/USD

<figure><img src="/files/8sFJRuS4eGsQcm24xAhn" alt="Left-to-right flowchart of the rsETH (L2) price feed: rate and Chainlink inputs combine into a USD price, with a staleness gate."><figcaption><p>rsETH (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 = (rsETH/ETH) × (ETH/USD) / 10^(rsETH/ETH decimals)
```

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

The rsETH/ETH leg is a Chainlink feed; the ETH/USD leg comes from the NAV's primary feed. The divisor is `10 ** RATE_FEED.decimals()`, captured once at construction as `_rateUnit`. Output is **8 decimals** (inherited from the ETH/USD term).

***

## Constructor

```solidity
constructor(
    address rsEth_,
    address rsEthToEthChainlink_,
    uint256 rsEthToEthHeartbeat_,
    address nav_,
    address baseAsset_
)
```

| Parameter              | Description                                                                                |
| ---------------------- | ------------------------------------------------------------------------------------------ |
| `rsEth_`               | rsETH token address (the supported underlying asset)                                       |
| `rsEthToEthChainlink_` | Chainlink rsETH/ETH aggregator                                                             |
| `rsEthToEthHeartbeat_` | Staleness window (seconds) for the rsETH/ETH 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

The rsETH/ETH Chainlink heartbeat is checked. `getLatestPrice()` returns `stale = true` if the rsETH/ETH feed satisfies `block.timestamp − updatedAt ≥ heartbeat`, if its answer is `≤ 0`, or 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` comes from the NAV's selected WETH feed; the reported `updatedAt` is the **older** of the two legs.

***

## Chains

Deployed on **Arbitrum**. The Ethereum mainnet counterpart is [rsETH (Mainnet)](/funds/infrastructure/onchain-accounting/price-feeds/rseth.md), which uses a rate provider against ETH/USD.


---

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