> 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/susde.md).

# sUSDe

Custom price feed for **Ethena Staked USDe**. sUSDe is an ERC-4626 vault share that accrues yield from Ethena's delta-neutral strategy. The price is derived from the vault's current share-to-USDe conversion rate multiplied by the Chainlink USDe/USD feed.

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

***

## Approach

`sUSDe.convertToAssets(1 sUSDe)` × USDe/USD (from the NAV's primary feed)

{% hint style="info" %}
The USDe/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 %}

<figure><img src="/files/Xvzwzasy0fLY2NpZQmMX" alt="Left-to-right flowchart of the sUSDe price feed: rate and Chainlink inputs combine into a USD price, with a staleness gate."><figcaption><p>sUSDe price feed — how its oracle inputs compose into a USD price, with the staleness gate.</p></figcaption></figure>

***

## Price calculation

```
decimals = sUSDe.decimals()                       // vault share decimals
rate     = sUSDe.convertToAssets(10^decimals)     // USDe per 1 sUSDe (vault decimals)
price    = rate × USDe_USD / 10^decimals
```

| Input               | Source                                              | Description                                                    |
| ------------------- | --------------------------------------------------- | -------------------------------------------------------------- |
| `convertToAssets()` | `IERC4626(sUSDe)`                                   | USDe backing per 1 sUSDe at the current accumulated yield rate |
| `USDe_USD`          | NAV base — `getPriceDataNoDivergence(USDe)` (8 dec) | the NAV's primary USDe/USD price                               |

`convertToAssets` is linear in shares, so dividing by the same `10^decimals` used as input yields the exchange rate (totalAssets/totalSupply). Vault decimals are read once at deploy. Result carries the feed's **8 decimals**.

***

## Constructor

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

| Parameter    | Description                                                                                                                                 |
| ------------ | ------------------------------------------------------------------------------------------------------------------------------------------- |
| `sUsde_`     | The sUSDe vault address (also used to read vault decimals)                                                                                  |
| `nav_`       | NAVCalculator (proxy) — supplies the base stablecoin's USD price via `getPriceDataNoDivergence`                                             |
| `baseAsset_` | The registered base stablecoin whose USD price is read (USDe); **must equal the vault's `asset()`** — reverts `BaseAssetMismatch` otherwise |

***

## Staleness

The price is stale if the NAV reports the base asset (USDe) stale — all its feeds stale. The base leg's `updatedAt` comes from the NAV's selected USDe feed. The `convertToAssets` rate has no heartbeat — it is a live view on the ERC-4626 vault.

***

## Chains

Deployed on **Ethereum mainnet** only.


---

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