Merge pull request #70 from quocle108/cache-quote-fee

Cache quote fee

Author: jonathunne

package-lock.json

@@ -31,7 +31,7 @@
   "dependencies": {
     "@tetherto/wdk-safe-relay-kit": "4.1.5",
     "@tetherto/wdk-wallet": "1.0.0-beta.7",
-    "@tetherto/wdk-wallet-evm": "1.0.0-beta.8",
+    "@tetherto/wdk-wallet-evm": "1.0.0-beta.10",
     "bare-node-runtime": "^1.1.4",
     "ethers": "6.14.4"
   },

package.json

@@ -40,7 +40,7 @@ import WalletAccountReadOnlyEvmErc4337 from './wallet-account-read-only-evm-erc-
 
 /** @typedef {import('@tetherto/wdk-safe-relay-kit').Safe4337Pack} Safe4337Pack */
 
-const FEE_TOLERANCE_COEFFICIENT = 120n
+const QUOTE_MAX_AGE_MS = 2 * 60 * 1_000
 
 const USDT_MAINNET_ADDRESS = '0xdAC17F958D2ee523a2206206994597C13D831ec7'
 
@@ -169,9 +169,10 @@ export default class WalletAccountEvmErc4337 extends WalletAccountReadOnlyEvmErc
 
     const { isSponsored, useNativeCoins } = mergedConfig
 
-    const { fee } = await this.quoteSendTransaction(tx, config)
+    const fee = this._getValidCachedFee(tx) ?? (await this.quoteSendTransaction(tx, config)).fee
+    this._lastQuote = undefined
 
-    const amountToApprove = (isSponsored || useNativeCoins) ? 0n : BigInt(fee * FEE_TOLERANCE_COEFFICIENT / 100n)
+    const amountToApprove = (isSponsored || useNativeCoins) ? 0n : fee
 
     const hash = await this._sendUserOperation([tx].flat(), {
       ...mergedConfig,
@@ -199,13 +200,14 @@ export default class WalletAccountEvmErc4337 extends WalletAccountReadOnlyEvmErc
 
     const tx = await WalletAccountEvm._getTransferTransaction(options)
 
-    const { fee } = await this.quoteSendTransaction(tx, config)
+    const fee = this._getValidCachedFee(tx) ?? (await this.quoteSendTransaction(tx, config)).fee
+    this._lastQuote = undefined
 
     if (!isSponsored && transferMaxFee !== undefined && fee >= transferMaxFee) {
       throw new Error('Exceeded maximum fee cost for transfer operation.')
     }
 
-    const amountToApprove = (isSponsored || useNativeCoins) ? 0n : BigInt(fee * FEE_TOLERANCE_COEFFICIENT / 100n)
+    const amountToApprove = (isSponsored || useNativeCoins) ? 0n : fee
 
     const hash = await this._sendUserOperation([tx], {
       ...mergedConfig,
@@ -255,6 +257,35 @@ export default class WalletAccountEvmErc4337 extends WalletAccountReadOnlyEvmErc
     return safe4337Pack
   }
 
+  /**
+   * Returns the cached fee if it exists, is not expired, and matches the given transaction.
+   * Clears cache on match or expiry; preserves it on mismatch.
+   *
+   * @private
+   * @param {EvmTransaction | EvmTransaction[]} tx - The transaction to match against.
+   * @returns {bigint | undefined} The cached fee, or undefined if not available, expired, or mismatched.
+   */
+  _getValidCachedFee (tx) {
+    const quote = this._lastQuote
+
+    if (!quote) {
+      return undefined
+    }
+
+    if (Date.now() - quote.createdAt > QUOTE_MAX_AGE_MS) {
+      this._lastQuote = undefined
+      return undefined
+    }
+
+    if (WalletAccountReadOnlyEvmErc4337._getTxKey(tx) !== quote.txKey) {
+      return undefined
+    }
+
+    this._lastQuote = undefined
+
+    return quote.fee
+  }
+
   /** @private */
   async _sendUserOperation (txs, { amountToApprove, ...config }) {
     const { useNativeCoins, paymasterToken, isSponsored, sponsorshipPolicyId } = config

src/wallet-account-evm-erc-4337.js

@@ -22,6 +22,8 @@ import { Safe4337Pack, GenericFeeEstimator, PimlicoFeeEstimator } from '@tethert
 
 import { ConfigurationError } from './errors.js'
 
+const FEE_TOLERANCE_COEFFICIENT = 120n
+
 /** @typedef {import('ethers').Eip1193Provider} Eip1193Provider */
 
 /** @typedef {import('@tetherto/wdk-safe-relay-kit').UserOperationReceipt} UserOperationReceipt */
@@ -37,6 +39,13 @@ import { ConfigurationError } from './errors.js'
 
 /** @typedef {import('@tetherto/wdk-wallet-evm').TypedData} TypedData */
 
+/**
+ * @typedef {Object} CachedQuote
+ * @property {bigint} fee - The estimated fee with tolerance buffer applied.
+ * @property {number} createdAt - The timestamp when the quote was created.
+ * @property {string} txKey - A serialized key of the transaction used for cache matching.
+ */
+
 /**
  * @typedef {Object} EvmErc4337WalletCommonConfig
  * @property {number} chainId - The blockchain's id (e.g., 1 for ethereum).
@@ -114,6 +123,14 @@ export default class WalletAccountReadOnlyEvmErc4337 extends WalletAccountReadOn
      */
     this._feeEstimator = undefined
 
+    /**
+     * Cached quote from the last fee estimation.
+     *
+     * @protected
+     * @type {CachedQuote | undefined}
+     */
+    this._lastQuote = undefined
+
     /**
      * The chain id.
      *
@@ -199,6 +216,9 @@ export default class WalletAccountReadOnlyEvmErc4337 extends WalletAccountReadOn
   /**
    * Quotes the costs of a send transaction operation.
    *
+   * The result is cached internally for up to 2 minutes. If `sendTransaction` is called with the
+   * same transaction within that window, the cached fee is reused without an additional RPC round-trip.
+   *
    * @param {EvmTransaction | EvmTransaction[]} tx - The transaction, or an array of multiple transactions to send in batch.
    * @param {Partial<EvmErc4337WalletPaymasterTokenConfig | EvmErc4337WalletSponsorshipPolicyConfig | EvmErc4337WalletNativeCoinsConfig>} [config] - If set, overrides the given configuration options.
    * @returns {Promise<Omit<TransactionResult, 'hash'>>} The transaction's quotes.
@@ -216,17 +236,24 @@ export default class WalletAccountReadOnlyEvmErc4337 extends WalletAccountReadOn
       return { fee: 0n }
     }
 
-    const fee = await this._getUserOperationGasCost([tx].flat(), {
+    const estimatedFee = await this._getUserOperationGasCost([tx].flat(), {
       ...mergedConfig,
       amountToApprove: useNativeCoins ? 0n : BigInt(Number.MAX_SAFE_INTEGER)
     })
 
-    return { fee: BigInt(fee) }
+    const fee = BigInt(estimatedFee) * FEE_TOLERANCE_COEFFICIENT / 100n
+
+    this._lastQuote = { fee, createdAt: Date.now(), txKey: WalletAccountReadOnlyEvmErc4337._getTxKey(tx) }
+
+    return { fee }
   }
 
   /**
    * Quotes the costs of a transfer operation.
    *
+   * The result is cached internally for up to 2 minutes. If `transfer` is called with the
+   * same transaction within that window, the cached fee is reused without an additional RPC round-trip.
+   *
    * @param {TransferOptions} options - The transfer's options.
    * @param {Partial<EvmErc4337WalletPaymasterTokenConfig | EvmErc4337WalletSponsorshipPolicyConfig | EvmErc4337WalletNativeCoinsConfig>} [config] - If set, overrides the given configuration options.
    * @returns {Promise<Omit<TransferResult, 'hash'>>} The transfer's quotes.
@@ -448,6 +475,17 @@ export default class WalletAccountReadOnlyEvmErc4337 extends WalletAccountReadOn
     return this._feeEstimator
   }
 
+  /**
+   * Returns a serialized key for transaction cache matching.
+   *
+   * @protected
+   * @param {EvmTransaction | EvmTransaction[]} tx - The transaction(s) to serialize.
+   * @returns {string} The serialized transaction key.
+   */
+  static _getTxKey (tx) {
+    return JSON.stringify([tx].flat(), (_, v) => typeof v === 'bigint' ? v.toString() : v)
+  }
+
   /** @private */
   async _getUserOperationGasCost (txs, { amountToApprove, ...config }) {
     const safe4337Pack = await this._getSafe4337Pack(config)