perf(api): cache gas price

api/_errors.ts

@@ -74,6 +74,18 @@ export class AcrossApiError extends Error {
   }
 }
 
+export class UnauthorizedError extends AcrossApiError {
+  constructor(args?: { message: string }, opts?: ErrorOptions) {
+    super(
+      {
+        message: args?.message ?? "Unauthorized",
+        status: HttpErrorToStatusCode.UNAUTHORIZED,
+      },
+      opts
+    );
+  }
+}
+
 export class InputError extends AcrossApiError {
   constructor(
     args: {

api/_utils.ts

@@ -61,10 +61,10 @@
   makeCacheGetterAndSetter,
 } from "./_cache";
 import {
   InputError,
   MissingParamError,
   InvalidParamError,
   handleErrorCondition,
   RouteNotEnabledError,
 } from "./_errors";
 
@@ -689,6 +689,7 @@
  * @param message An optional message to include in the transfer
  * @param relayerAddress An optional relayer address to use for the transfer
  * @param gasUnits An optional gas unit to use for the transfer
+ * @param gasPrice An optional gas price to use for the transfer
  * @returns The a promise to the relayer fee for the given `amount` of transferring `l1Token` to `destinationChainId`
  */
 export const getRelayerFeeDetails = async (
@@ -703,7 +704,8 @@
   },
   tokenPrice?: number,
   relayerAddress?: string,
-  gasUnits?: sdk.utils.BigNumberish
+  gasUnits?: sdk.utils.BigNumberish,
+  gasPrice?: sdk.utils.BigNumberish
 ): Promise<sdk.relayFeeCalculator.RelayerFeeDetails> => {
   const {
     inputToken,
@@ -731,7 +733,7 @@
     sdk.utils.isMessageEmpty(message),
     relayerAddress,
     tokenPrice,
-    undefined,
+    gasPrice,
     gasUnits
   );
 };
@@ -1955,6 +1957,26 @@
   );
 }
 
+export function latestGasPriceCache(chainId: number) {
+  const ttlPerChain = {
+    default: 30,
+    [CHAIN_IDs.ARBITRUM]: 15,
+  };
+
+  return makeCacheGetterAndSetter(
+    buildInternalCacheKey("latestGasPriceCache", chainId),
+    ttlPerChain[chainId] || ttlPerChain.default,
+    async () => {
+      const gasPrice = await sdk.gasPriceOracle.getGasPriceEstimate(
+        getProvider(chainId),
+        chainId
+      );
+      return gasPrice.maxFeePerGas;
+    },
+    (bnFromCache) => BigNumber.from(bnFromCache)
+  );
+}
+
 /**
  * Builds a URL search string from an object of query parameters.
  *

api/cron-cache-balances.ts

@@ -9,6 +9,7 @@ import {
   handleErrorCondition,
   latestBalanceCache,
 } from "./_utils";
+import { UnauthorizedError } from "./_errors";
 
 import mainnetChains from "../src/data/chains_1.json";
 
@@ -27,7 +28,7 @@ const handler = async (
       !process.env.CRON_SECRET ||
       authHeader !== `Bearer ${process.env.CRON_SECRET}`
     ) {
-      return response.status(401).json({ success: false });
+      throw new UnauthorizedError();
     }
 
     const {

api/cron-cache-gas-prices.ts

@@ -0,0 +1,100 @@
+import { VercelResponse } from "@vercel/node";
+import { gasPriceOracle } from "@across-protocol/sdk";
+import { TypedVercelRequest } from "./_types";
+import {
+  HUB_POOL_CHAIN_ID,
+  getLogger,
+  handleErrorCondition,
+  latestGasPriceCache,
+  getProvider,
+} from "./_utils";
+import { UnauthorizedError } from "./_errors";
+
+import mainnetChains from "../src/data/chains_1.json";
+
+const updateIntervalsSecPerChain = {
+  default: 10,
+  1: 12,
+};
+
+const maxDurationSec = 60;
+
+const handler = async (
+  request: TypedVercelRequest<Record<string, never>>,
+  response: VercelResponse
+) => {
+  const logger = getLogger();
+  logger.debug({
+    at: "CronCacheGasPrices",
+    message: "Starting cron job...",
+  });
+  try {
+    const authHeader = request.headers?.["authorization"];
+    if (
+      !process.env.CRON_SECRET ||
+      authHeader !== `Bearer ${process.env.CRON_SECRET}`
+    ) {
+      throw new UnauthorizedError();
+    }
+
+    // Skip cron job on testnet
+    if (HUB_POOL_CHAIN_ID !== 1) {
+      logger.info({
+        at: "CronCacheGasPrices",
+        message: "Skipping cron job on testnet",
+      });
+      return;
+    }
+
+    // This marks the timestamp when the function started
+    const functionStart = Date.now();
+
+    // The minimum interval for Vercel Serverless Functions cron jobs is 1 minute.
+    // But we want to update gas prices more frequently than that.
+    // To circumvent this, we run the function in a loop and update gas prices every
+    // `updateIntervalSec` seconds and stop after `maxDurationSec` seconds (1 minute).
+    const gasPricePromises = mainnetChains.map(async (chain) => {
+      while (true) {
+        const diff = Date.now() - functionStart;
+
+        // Stop after `maxDurationSec` seconds
+        if (diff >= maxDurationSec * 1000) {
+          break;
+        }
+
+        // Update gas price every `updateIntervalSec` seconds
+        const gasPrice = await gasPriceOracle.getGasPriceEstimate(
+          getProvider(chain.chainId),
+          chain.chainId
+        );
+        await latestGasPriceCache(chain.chainId).set(gasPrice.maxFeePerGas);
+
+        // Sleep for `updateIntervalSec` seconds
+        const updateIntervalSec =
+          updateIntervalsSecPerChain[
+            chain.chainId as keyof typeof updateIntervalsSecPerChain
+          ] || updateIntervalsSecPerChain.default;
+        await new Promise((resolve) =>
+          setTimeout(resolve, updateIntervalSec * 1000)
+        );
+      }
+    });
+    await Promise.all(gasPricePromises);
+
+    logger.debug({
+      at: "CronCacheGasPrices",
+      message: "Finished",
+    });
+    response.status(200);
+    response.send("OK");
+  } catch (error: unknown) {
+    return handleErrorCondition(
+      "cron-cache-gas-prices",
+      response,
+      logger,
+      error
+    );
+  }
+};
+
+export default handler;

api/limits.ts

@@ -33,6 +33,7 @@ import {
   parsableBigNumberString,
   validateDepositMessage,
   getCachedFillGasUsage,
+  latestGasPriceCache,
 } from "./_utils";
 import { MissingParamError } from "./_errors";
 
@@ -163,7 +164,7 @@ const handler = async (
       message,
     };
 
-    const [tokenPriceNative, _tokenPriceUsd, latestBlock, gasUnits] =
+    const [tokenPriceNative, _tokenPriceUsd, latestBlock, gasUnits, gasPrice] =
       await Promise.all([
         getCachedTokenPrice(
           l1Token.address,
@@ -177,6 +178,7 @@ const handler = async (
           : getCachedFillGasUsage(depositArgs, {
               relayerAddress: relayer,
             }),
+        latestGasPriceCache(destinationChainId).get(),
       ]);
     const tokenPriceUsd = ethers.utils.parseUnits(_tokenPriceUsd.toString());
 
@@ -187,7 +189,13 @@ const handler = async (
       transferRestrictedBalances,
       fullRelayerMainnetBalances,
     ] = await Promise.all([
-      getRelayerFeeDetails(depositArgs, tokenPriceNative, relayer, gasUnits),
+      getRelayerFeeDetails(
+        depositArgs,
+        tokenPriceNative,
+        relayer,
+        gasUnits,
+        gasPrice
+      ),
       callViaMulticall3(provider, multiCalls, {
         blockTag: latestBlock.number,
       }),

package.json

@@ -7,7 +7,7 @@
     "@across-protocol/constants": "^3.1.15",
     "@across-protocol/contracts": "^3.0.10",
     "@across-protocol/contracts-v3.0.6": "npm:@across-protocol/[email protected]",
-    "@across-protocol/sdk": "^3.1.32",
+    "@across-protocol/sdk": "^3.2.3",
     "@amplitude/analytics-browser": "^2.3.5",
     "@balancer-labs/sdk": "1.1.6-beta.16",
     "@emotion/react": "^11.13.0",

vercel.json

@@ -6,6 +6,11 @@
       "schedule": "* * * * *"
     }
   ],
+  "functions": {
+    "api/cron-cache-gas-prices.ts": {
+      "maxDuration": 90
+    }
+  },
   "rewrites": [
     {
       "source": "/api/deposit/status",

yarn.lock

@@ -80,15 +80,16 @@
     axios "^1.6.2"
     zksync-web3 "^0.14.3"
 
-"@across-protocol/sdk@^3.1.32":
-  version "3.1.32"
-  resolved "https://registry.yarnpkg.com/@across-protocol/sdk/-/sdk-3.1.32.tgz#04248d6f722bf2706c9d2b9cd0bf228510a07ff6"
-  integrity sha512-BXv1dJPvZw3Ozsm1LPlFQD1OSdDYPZQH7czmSPCOEtrHoVl1eScKHxdu53hbD09//YhoVFF+i2W4auLXCJ8Stg==
+"@across-protocol/sdk@^3.2.3":
+  version "3.2.3"
+  resolved "https://registry.yarnpkg.com/@across-protocol/sdk/-/sdk-3.2.3.tgz#9843a9a40b818af372c6022634046da8488d6997"
+  integrity sha512-IkHNxRWSI3G2VWMLX8+K1j7nSg44oeWaH19MzpSw8QR5AzgYv/hlzpGckSn2bdM7LFnWvOytoAVFmdBrcdFJ1Q==
   dependencies:
     "@across-protocol/across-token" "^1.0.0"
     "@across-protocol/constants" "^3.1.14"
     "@across-protocol/contracts" "^3.0.10"
     "@eth-optimism/sdk" "^3.3.1"
+    "@ethersproject/bignumber" "^5.7.0"
     "@pinata/sdk" "^2.1.0"
     "@types/mocha" "^10.0.1"
     "@uma/sdk" "^0.34.1"