add blend pool yields

src/adaptors/blend-pools/index.js

@@ -0,0 +1,89 @@
+const {
+  PoolConfig,
+  ReserveData,
+  BackstopConfig,
+  Pool,
+  BackstopToken,
+  Backstop,
+  FixedMath,
+} = require('@blend-capital/blend-sdk');
+const { getPrices, keepFinite, formatChain } = require('../utils');
+
+const BACKSTOP_ID = 'CAO3AGAMZVRMHITL36EJ2VZQWKYRPWMQAPDQD5YEOF3GIF7T44U4JAL3';
+const BLND_ID = 'CD25MNVTZDL4Y3XBCPCJXGXATV5WUHHOWMYFF4YBEGU5FCPGMYTVG5JY';
+const network = {
+  rpc: 'https://soroban-rpc.creit.tech/',
+  passphrase: 'Public Global Stellar Network ; September 2015',
+};
+
+const getApy = async (poolId, backstop) => {
+  const pool = await Pool.load(network, poolId);
+  // Skip pools that have been admin frozen - Pool is very likely to be broken
+  if (pool.config.status === 4) return [];
+  const prices = await getPrices(pool.config.reserveList, 'stellar');
+  let pools = [];
+  for (const reserve of pool.reserves.values()) {
+    const price = prices.pricesByAddress[reserve.assetId.toLowerCase()];
+    if (price) {
+      let supplyEmissionsPerAsset = reserve.emissionsPerYearPerSuppliedAsset();
+      let borrowEmissionsPerAsset = reserve.emissionsPerYearPerBorrowedAsset();
+      let supplyEmissionsAPR = undefined;
+      let borrowEmissionsAPR = undefined;
+      // The backstop token is an 80/20 weighted lp token of blnd and usdc respectively
+      // (Calculated using balancer spot equation)
+      // @TODO replace with coingecko price after listing
+      const usdcPerBlnd =
+        FixedMath.toFloat(backstop.backstopToken.usdc, 7) /
+        0.2 /
+        (FixedMath.toFloat(backstop.backstopToken.blnd, 7) / 0.8);
+      if (supplyEmissionsPerAsset > 0) {
+        supplyEmissionsAPR = (supplyEmissionsPerAsset * usdcPerBlnd) / price;
+      }
+      if (borrowEmissionsPerAsset > 0) {
+        borrowEmissionsAPR = (borrowEmissionsPerAsset * usdcPerBlnd) / price;
+      }
+      // Estimate borrow APY compoumded daily
+      const borrowApy = (1 + reserve.borrowApr / 365) ** 365 - 1;
+      let totalSupply = reserve.totalSupplyFloat() * price;
+      let totalBorrow = reserve.totalLiabilitiesFloat() * price;
+
+      const url = `https://mainnet.blend.capital/dashboard/?poolId=${poolId}`;
+
+      pools.push({
+        pool: `${poolId}-${reserve.assetId}-stellar`.toLowerCase(),
+        chain: formatChain('stellar'),
+        project: 'blend-pools',
+        symbol: reserve.tokenMetadata.symbol,
+        tvlUsd: totalSupply - totalBorrow,
+        // Supply is kept as APR to prevent overestimation of APY
+        apyBase: reserve.supplyApr,
+        apyReward: supplyEmissionsAPR,
+        underlyingTokens: [reserve.assetId],
+        rewardTokens: borrowEmissionsAPR || supplyEmissionsAPR ? [BLND_ID] : [],
+        totalSupplyUsd: totalSupply,
+        totalBorrowUsd: totalBorrow,
+        apyBaseBorrow: borrowApy,
+        apyRewardBorrow: borrowEmissionsAPR,
+        ltv: totalBorrow / totalSupply,
+        url,
+      });
+    }
+  }
+  return pools;
+};
+
+const apy = async () => {
+  let backstop = await Backstop.load(network, BACKSTOP_ID);
+  const pools = await Promise.allSettled(
+    backstop.config.rewardZone.map(async (poolId) => getApy(poolId, backstop))
+  );
+  return pools
+    .filter((i) => i.status === 'fulfilled' && i.value !== undefined)
+    .map((i) => i.value)
+    .flat()
+    .filter((p) => p !== undefined && keepFinite(p));
+};
+
+module.exports = {
+  apy,
+};

src/adaptors/package.json

@@ -7,7 +7,11 @@
   "author": "",
   "license": "ISC",
   "dependencies": {
+    "@blend-capital/blend-sdk": "^2.1.1",
     "@defillama/sdk": "^5.0.60",
+    "@stacks/network": "^6.13.0",
+    "@stacks/transactions": "^6.15.0",
+    "@ton/ton": "14.0.0",
     "@types/jest": "^28.1.6",
     "@uniswap/sdk-core": "^5.3.0",
     "@uniswap/v3-sdk": "^3.13.0",
@@ -24,10 +28,7 @@
     "lodash": "^4.17.21",
     "node-fetch": "^2.6.1",
     "superagent": "^6.1.0",
-    "web3": "^4.9.0",
-    "@ton/ton": "14.0.0",
-    "@stacks/network": "^6.13.0",
-    "@stacks/transactions": "^6.15.0"
+    "web3": "^4.9.0"
   },
   "devDependencies": {
     "jest": "^28.1.3",