> 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/syrupusdc-l2.md).

# syrupUSDC (L2)

Custom price feed for **Maple Finance syrupUSDC** on Layer 2 networks. On L2s, a dedicated Chainlink syrupUSDC/USDC feed is available and used directly, multiplied by the USDC/USD price read from the NAV's own primary feed.

**Source:** [`syrupUSDC_L2_CustomPriceFeed.sol`](https://github.com/karpatkey/onchain-accounting/blob/main/src/prices/protocols/syrupUSDC_L2_CustomPriceFeed.sol)

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

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

***

## Approach

Chainlink syrupUSDC/USDC × USDC/USD (from the NAV's primary feed via `getPriceDataNoDivergence(USDC)`)

<figure><img src="/files/3q8EFbUKDTO0aN8LWaDP" alt="Left-to-right flowchart of the syrupUSDC (L2) price feed: rate and Chainlink inputs combine into a USD price, with a staleness gate."><figcaption><p>syrupUSDC (L2) price feed — how its oracle inputs compose into a USD price, with the staleness gate.</p></figcaption></figure>

***

## Price calculation

```
price = syrupUSDC_to_USDC_rate × USDC_USD / 10^syrupUSDC_to_USDC_feed.decimals()
```

| Input                    | Source                                              | Description                      |
| ------------------------ | --------------------------------------------------- | -------------------------------- |
| `syrupUSDC_to_USDC_rate` | Chainlink syrupUSDC/USDC                            | syrupUSDC exchange rate in USDC  |
| `USDC_USD`               | NAV base — `getPriceDataNoDivergence(USDC)` (8 dec) | the NAV's primary USDC/USD price |

The syrupUSDC/USDC rate is read live from Chainlink; the USDC/USD base term is read from the NAV's primary feed. Result carries the feed's **8 decimals**.

***

## Constructor

```solidity
constructor(
    address syrupUsdc_,
    address syrupUsdcToUsdcChainlink_,
    uint256 syrupUsdcToUsdcHeartbeat_,
    address nav_,
    address baseAsset_
)
```

| Parameter                   | Description                                                                                     |
| --------------------------- | ----------------------------------------------------------------------------------------------- |
| `syrupUsdc_`                | The syrupUSDC token address                                                                     |
| `syrupUsdcToUsdcChainlink_` | Chainlink syrupUSDC/USDC oracle                                                                 |
| `syrupUsdcToUsdcHeartbeat_` | Staleness window (seconds) for the syrupUSDC/USDC feed                                          |
| `nav_`                      | NAVCalculator (proxy) — supplies the base stablecoin's USD price via `getPriceDataNoDivergence` |
| `baseAsset_`                | The registered base stablecoin whose USD price is read (USDC)                                   |

***

## Staleness

The syrupUSDC/USDC rate leg checks its own Chainlink heartbeat: it is stale if the rate is `≤ 0` or if `block.timestamp − effectiveUpdatedAt ≥ heartbeat` (`effectiveUpdatedAt` clamped to `block.timestamp`). The price is also stale if the base USD price is `≤ 0`, or if the NAV reports the base asset (USDC) stale — all its feeds stale. The base leg's `updatedAt` comes from the NAV's selected USDC feed. The reported `updatedAt` is the older (minimum) of the rate leg and the base leg.

***

## Chains

Deployed on **Arbitrum**. Mainnet uses [syrupUSDC (Mainnet)](/funds/infrastructure/onchain-accounting/price-feeds/syrupusdc.md), which derives the rate from the ERC-4626 vault instead.


---

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