Add fallback for gas fee estimation in zkSync (#8637)

Author: 0xFirekeeper

.changeset/spotty-experts-rest.md

@@ -0,0 +1,5 @@
+---
+"thirdweb": patch
+---
+
+newer zkos chains no longer support zks\_ rpc endpoints, fallback to evm std

packages/thirdweb/src/transaction/actions/zksync/send-eip712-transaction.test.ts

@@ -5,9 +5,13 @@ import {
   TEST_ACCOUNT_B,
 } from "../../../../test/src/test-wallets.js";
 import { zkSyncSepolia } from "../../../chains/chain-definitions/zksync-sepolia.js";
+import { defineChain } from "../../../chains/utils.js";
 import { deployPublishedContract } from "../../../extensions/prebuilts/deploy-published.js";
 import { prepareTransaction } from "../../prepare-transaction.js";
-import { sendEip712Transaction } from "./send-eip712-transaction.js";
+import {
+  getZkGasFees,
+  sendEip712Transaction,
+} from "./send-eip712-transaction.js";
 
 describe("sendEip712Transaction", () => {
   // re-enable for testing, but disable for CI since it requires testnet funds
@@ -52,4 +56,34 @@ describe("sendEip712Transaction", () => {
     expect(address).toBeDefined();
     expect(address.length).toBe(42);
   });
+
+  it("should fallback to standard EVM methods when zks_estimateFee is not available", async () => {
+    // Chain 278701 is a zkSync chain that doesn't support zks_estimateFee
+    const zkSyncChainWithoutZksSupport = defineChain(278701);
+
+    // Use a transaction with pre-defined gas to skip estimation (which requires balance)
+    // This tests that the fallback path is taken for fee estimation
+    const transaction = prepareTransaction({
+      chain: zkSyncChainWithoutZksSupport,
+      client: TEST_CLIENT,
+      gas: 21000n, // pre-define gas to skip eth_estimateGas
+      to: TEST_ACCOUNT_B.address,
+      value: 0n,
+    });
+
+    const gasFees = await getZkGasFees({
+      transaction,
+      from: TEST_ACCOUNT_A.address as `0x${string}`,
+    });
+
+    // Verify fallback worked - should have valid gas values
+    expect(gasFees.gas).toBeDefined();
+    expect(gasFees.gas).toBeGreaterThan(0n);
+    expect(gasFees.maxFeePerGas).toBeDefined();
+    expect(gasFees.maxFeePerGas).toBeGreaterThan(0n);
+    expect(gasFees.maxPriorityFeePerGas).toBeDefined();
+    expect(gasFees.maxPriorityFeePerGas).toBeGreaterThan(0n);
+    // Fallback should use 100k for gasPerPubdata
+    expect(gasFees.gasPerPubdata).toBe(100000n);
+  });
 });

packages/thirdweb/src/transaction/actions/zksync/send-eip712-transaction.ts

@@ -180,25 +180,59 @@ export async function getZkGasFees(args: {
   ) {
     const rpc = getRpcClient(transaction);
     const params = await formatTransaction({ from, transaction });
-    const result = (await rpc({
-      // biome-ignore lint/suspicious/noExplicitAny: TODO add to RPC method types
-      method: "zks_estimateFee" as any,
-      // biome-ignore lint/suspicious/noExplicitAny: TODO add to RPC method types
-      params: [replaceBigInts(params, toHex)] as any,
-    })) as {
-      gas_limit: string;
-      max_fee_per_gas: string;
-      max_priority_fee_per_gas: string;
-      gas_per_pubdata_limit: string;
-    };
-    gas = toBigInt(result.gas_limit) * 2n; // overestimating to avoid issues when not accounting for paymaster extra gas ( we should really pass the paymaster input above for better accuracy )
-    const baseFee = toBigInt(result.max_fee_per_gas);
-    maxFeePerGas = baseFee * 2n; // bumping the base fee per gas to ensure fast inclusion
-    maxPriorityFeePerGas = toBigInt(result.max_priority_fee_per_gas) || 1n;
-    gasPerPubdata = toBigInt(result.gas_per_pubdata_limit) * 2n; // doubling for fast inclusion;
-    if (gasPerPubdata < 50000n) {
-      // enforce a minimum gas per pubdata limit
-      gasPerPubdata = 50000n;
+
+    // Try zkSync-specific fee estimation first, fallback to standard EVM methods
+    try {
+      const result = (await rpc({
+        // biome-ignore lint/suspicious/noExplicitAny: TODO add to RPC method types
+        method: "zks_estimateFee" as any,
+        // biome-ignore lint/suspicious/noExplicitAny: TODO add to RPC method types
+        params: [replaceBigInts(params, toHex)] as any,
+      })) as {
+        gas_limit: string;
+        max_fee_per_gas: string;
+        max_priority_fee_per_gas: string;
+        gas_per_pubdata_limit: string;
+      };
+      gas = toBigInt(result.gas_limit) * 2n; // overestimating to avoid issues when not accounting for paymaster extra gas ( we should really pass the paymaster input above for better accuracy )
+      const baseFee = toBigInt(result.max_fee_per_gas);
+      maxFeePerGas = baseFee * 2n; // bumping the base fee per gas to ensure fast inclusion
+      maxPriorityFeePerGas = toBigInt(result.max_priority_fee_per_gas) || 1n;
+      gasPerPubdata = toBigInt(result.gas_per_pubdata_limit) * 2n; // doubling for fast inclusion;
+      if (gasPerPubdata < 50000n) {
+        // enforce a minimum gas per pubdata limit
+        gasPerPubdata = 50000n;
+      }
+    } catch {
+      // Fallback to standard EVM methods if zks_estimateFee is not available
+      const [{ estimateGas }, { getDefaultGasOverrides }] = await Promise.all([
+        import("../estimate-gas.js"),
+        import("../../../gas/fee-data.js"),
+      ]);
+
+      const [estimatedGas, gasOverrides] = await Promise.all([
+        gas === undefined
+          ? estimateGas({ transaction, from })
+          : Promise.resolve(gas),
+        getDefaultGasOverrides(transaction.client, transaction.chain),
+      ]);
+
+      gas = estimatedGas * 2n; // overestimating similar to zkSync estimation
+      if ("maxFeePerGas" in gasOverrides && gasOverrides.maxFeePerGas) {
+        maxFeePerGas = gasOverrides.maxFeePerGas * 2n; // bumping for fast inclusion
+      } else if ("gasPrice" in gasOverrides && gasOverrides.gasPrice) {
+        maxFeePerGas = gasOverrides.gasPrice * 2n;
+      }
+      if (
+        "maxPriorityFeePerGas" in gasOverrides &&
+        gasOverrides.maxPriorityFeePerGas
+      ) {
+        maxPriorityFeePerGas = gasOverrides.maxPriorityFeePerGas;
+      } else {
+        maxPriorityFeePerGas = 1n;
+      }
+      // Use 100k as default gasPerPubdata for non-zkSync chains
+      gasPerPubdata = 100000n;
     }
   }
   return {