> ## Documentation Index
> Fetch the complete documentation index at: https://kamino.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Calculate Extra Farm Reward APY

> Calculate APY for extra farm stablecoin rewards

<Note>
  Extra farms provide additional rewards to users who deposit specific collateral and borrow specific assets.
</Note>

## Calculate Extra Farm Reward APY

Calculate APY for extra farm rewards paid in stablecoins like CASH that are pegged to USD.

<Steps>
  <Step>
    ### Import Dependencies

    Import the required packages for Solana RPC communication, Kamino SDK operations, and decimal calculations.

    ```typescript theme={null}
    import { createSolanaRpc, address } from '@solana/kit';
    import { FarmState, calculateCurrentRewardPerToken } from '@kamino-finance/farms-sdk';
    import { KaminoMarket, PROGRAM_ID, lamportsToNumberDecimal } from '@kamino-finance/klend-sdk';
    import Decimal from 'decimal.js';

    type ExtraFarm = { market: string; farm: string; collMint: string; debtMint: string };
    type Resources = { 'mainnet-beta': { extraFarms: ExtraFarm[] } };
    ```
  </Step>

  <Step>
    ### Initialize RPC and Load Market

    Set up the Solana RPC connection and load the Kamino market.

    ```typescript theme={null}
    const rpc = createSolanaRpc('https://api.mainnet-beta.solana.com');
    const mainMarketAddress = address('7u3HeHxYDLhnCoErrtycNokbQYbWGzLs6JSDqGAv5PfF');

    // Load market and get CASH and SOL mints from reserves
    const market = await KaminoMarket.load(rpc, mainMarketAddress, 400, PROGRAM_ID);

    let cashReserve, solReserve;
    for (const reserve of market!.reserves.values()) {
      if (reserve.stats.symbol === 'CASH') cashReserve = reserve;
      if (reserve.stats.symbol === 'SOL') solReserve = reserve;
    }

    if (!cashReserve || !solReserve) {
      throw new Error('CASH or SOL reserve not found');
    }

    const cashMint = cashReserve.getLiquidityMint().toString();
    const solMint = solReserve.getLiquidityMint().toString();
    ```

    <Info>
      This example targets the SOL/CASH extra farm pair where users deposit SOL collateral and borrow CASH to earn rewards.
    </Info>
  </Step>

  <Step>
    ### Get and Filter Extra Farms

    Fetch the list of extra farms from the CDN and filter by SOL collateral and CASH debt.

    ```typescript theme={null}
    // Get extraFarms from CDN API and filter by SOL/CASH pair
    const cdnRes = await fetch('https://cdn.kamino.finance/resources.json');
    const allResources = (await cdnRes.json()) as Resources;

    const kaminoResources = allResources['mainnet-beta'];
    const extraFarmsForMarket = kaminoResources.extraFarms.filter((f) => f.market === mainMarketAddress.toString());

    // Filter by collateral (SOL) and debt (CASH) mints
    const solCashFarms = extraFarmsForMarket.filter((f) => f.collMint === solMint && f.debtMint === cashMint);
    ```

    <Info>
      The CDN resources endpoint provides a list of all extra farms. We filter for farms that specifically reward SOL collateral deposits paired with CASH borrows.
    </Info>
  </Step>

  <Step>
    ### Fetch All Farm States in Batch

    Fetch all farm states in a single batch request for better performance.

    ```typescript theme={null}
    // Fetch all farm states in batch
    const farmAddresses = solCashFarms.map((f) => address(f.farm));
    const farmStates = await FarmState.fetchMultiple(rpc, farmAddresses);

    const farms = solCashFarms.flatMap((extraFarm, index) => {
      const farmState = farmStates[index];
      return farmState ? [{ farm: extraFarm.farm, farmState }] : [];
    });
    ```

    <Info>
      Using `FarmState.fetchMultiple` fetches all farm states in a single batch request.
    </Info>
  </Step>

  <Step>
    ### Calculate APY for SOL/CASH Farms

    Loop through the fetched farms and calculate APY for CASH rewards.

    ```typescript theme={null}
    for (const { farm, farmState } of farms) {
      const totalStaked = lamportsToNumberDecimal(
        farmState.totalStakedAmount.toString(),
        farmState.token.decimals.toNumber() || 6
      );

      const cashReward = farmState.rewardInfos.find(
        (r) => r.token.mint.toString() === cashMint && r.rewardsAvailable.gtn(0)
      );

      if (cashReward && !totalStaked.isZero()) {
        const currentTime = new Decimal(Date.now() / 1000);

        // Calculate APY from farm rewards
        const rewardPerTokenPerSecond = calculateCurrentRewardPerToken(cashReward, currentTime); // returns the raw value
        const divisor = new Decimal(10)
          .pow(cashReward.rewardsPerSecondDecimals.toString())
          .mul(new Decimal(10).pow(cashReward.token.decimals.toString()));
        const adjustedRewardPerToken = new Decimal(rewardPerTokenPerSecond).div(divisor);
        const dailyRewards = adjustedRewardPerToken.mul(86400);
        const apy = Decimal.pow(dailyRewards.div(totalStaked).plus(1), 365).minus(1);

        console.log(`ExtraFarm: ${farm}`);
        console.log(`  CASH APY: ${(apy.toNumber() * 100).toFixed(2)}%\n`);
      }
    }
    ```

    <Check>
      The script outputs the APY for SOL/CASH extra farms paying CASH rewards. The `calculateCurrentRewardPerToken` helper from farms-sdk handles the reward schedule logic. Since CASH is pegged to USD, no price lookup is required.
    </Check>
  </Step>
</Steps>