> 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/wsteth.md).

# wstETH

wstETH is the non-rebasing wrapped form of Lido's staked ETH (stETH). It is priced **purely from its on-chain redemption rate** — no market oracle sits in the pricing path. This `ICustomPriceFeed` adapter reads Lido's wrap rate and scales it by the NAV's own ETH/USD. Any market divergence (e.g. a stETH depeg) is surfaced by a market **monitor** feed, not by moving this price.

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

{% hint style="info" %}
**Mainnet feed.** The L2 deployments use a different oracle composition — see [wstETH (L2)](/funds/infrastructure/onchain-accounting/price-feeds/wsteth-l2.md).
{% endhint %}

***

## Approach

`stEthPerToken()` × ETH/USD — the wrap rate gives ETH per wstETH (treating **stETH/ETH ≡ 1.0**, Lido's fundamental redemption invariant), then ETH/USD converts to USD. This is a pure-fundamental [`BaseCustomPriceFeed`](/funds/infrastructure/onchain-accounting/price-feeds.md#supported-feed-types) subclass: it implements only the `_rate()` hook and carries no market stETH/ETH leg. The ETH/USD term is not a hardcoded oracle — it is the NAV's own price for WETH (via `getPriceDataNoDivergence(WETH)`).

<figure><img src="/files/PznxZFfuX6u1r5eHEFyH" alt="Left-to-right flowchart of the wstETH (Mainnet) price feed: the on-chain wrap rate scaled by the NAV&#x27;s ETH/USD, with a staleness gate."><figcaption><p>wstETH (Mainnet) price feed — the on-chain wrap rate scaled by the NAV's ETH/USD, with the staleness gate.</p></figcaption></figure>

{% hint style="info" %}
The ETH/USD term is sourced from the NAV's own primary feed — 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 = stEthPerToken (18) × (ETH/USD, NAV-selected) (8) / 1e18      // USD, 8 dec
```

| Input           | Source                                             | Description                        |
| --------------- | -------------------------------------------------- | ---------------------------------- |
| `stEthPerToken` | `IwstETH.stEthPerToken()` on wstETH (18 dec)       | stETH per 1 wstETH (the wrap rate) |
| ETH/USD         | **NAV** — `getPriceDataNoDivergence(WETH)` (8 dec) | the NAV's primary WETH/USD price   |

The wrap rate `stEthPerToken` increases monotonically as Lido staking rewards accrue. Pricing off `stEthPerToken` alone assumes 1 stETH is redeemable \~1:1 for ETH; a real stETH depeg does **not** move this price but instead trips the divergence monitor (below). Output decimals are inherited from the ETH/USD feed (8).

***

## Constructor

```solidity
constructor(
    address wstEth_,
    address nav_,
    address baseAsset_
)
```

| Parameter    | Description                                                                                |
| ------------ | ------------------------------------------------------------------------------------------ |
| `wstEth_`    | wstETH 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)                                   |

***

## Staleness

`getLatestPrice()` returns stale if `stEthPerToken()` returns `0`, or if the NAV reports the base asset (WETH) primary feed stale. There is no market-leg heartbeat — the wrap-rate call has no independent heartbeat, and the only external timestamp is the NAV's selected WETH feed, which supplies the reported `updatedAt`.

***

## Divergence monitors

wstETH carries a **divergence tolerance of 250 bps** and is watched by two market **monitor** feeds — a Redstone and a Chainlink wstETH/USD feed. On each NAV read the primary is compared against them; if the worst-case deviation exceeds 250 bps the asset is flagged `irregular` (a signal, not a price change). See [Primary feed and divergence monitors](/funds/infrastructure/onchain-accounting/price-feeds.md#primary-feed-and-divergence-monitors).

***

## Chains

Deployed on **Ethereum**. For the rollup deployments using a direct Chainlink wstETH/ETH feed, see [wstETH (L2)](/funds/infrastructure/onchain-accounting/price-feeds/wsteth-l2.md).


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.kpk.io/funds/infrastructure/onchain-accounting/price-feeds/wsteth.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.