feat(dapp-client): cache signed calls from fee options

Author: tolgahan-arikan

packages/wallet/dapp-client/src/ChainSessionManager.ts

@@ -84,6 +84,11 @@ export class ChainSessionManager {
   public loginMethod: LoginMethod | null = null
   public userEmail: string | null = null
   private guard?: GuardConfig
+  private lastSignedCallCache?: {
+    fingerprint: string
+    signedCall: { to: Address.Address; data: Hex.Hex }
+    createdAtMs: number
+  }
 
   /**
    * @param chainId The ID of the chain this manager is responsible for.
@@ -851,6 +856,11 @@ export class ChainSessionManager {
     }))
     try {
       const signedCall = await this._buildAndSignCalls(callsToSend)
+      this.lastSignedCallCache = {
+        fingerprint: this._fingerprintCalls(callsToSend),
+        signedCall,
+        createdAtMs: Date.now(),
+      }
       const feeOptions = await this.relayer.feeOptions(signedCall.to, this.chainId, callsToSend)
       return feeOptions.options
     } catch (err) {
@@ -907,7 +917,7 @@ export class ChainSessionManager {
           callsToSend.unshift(transferCall)
         }
       }
-      const signedCalls = await this._buildAndSignCalls(callsToSend)
+      const signedCalls = this._getCachedSignedCall(callsToSend) ?? (await this._buildAndSignCalls(callsToSend))
       const hash = await this.relayer.relay(signedCalls.to, signedCalls.data, this.chainId)
       const status = await this._waitForTransactionReceipt(hash.opHash, this.chainId)
       if (status.status === 'confirmed') {
@@ -1101,4 +1111,42 @@ export class ChainSessionManager {
     await this.sequenceStorage.clearExplicitSessions()
     await this.sequenceStorage.clearSessionlessConnection()
   }
+
+  private _getCachedSignedCall(calls: Payload.Call[]): { to: Address.Address; data: Hex.Hex } | null {
+    if (!this.lastSignedCallCache) {
+      return null
+    }
+    const ttlMs = 30_000
+    if (Date.now() - this.lastSignedCallCache.createdAtMs > ttlMs) {
+      this.lastSignedCallCache = undefined
+      return null
+    }
+    const fingerprint = this._fingerprintCalls(calls)
+    if (!fingerprint) {
+      return null
+    }
+    if (fingerprint !== this.lastSignedCallCache.fingerprint) {
+      return null
+    }
+    return this.lastSignedCallCache.signedCall
+  }
+
+  private _fingerprintCalls(calls: Payload.Call[]): string | null {
+    try {
+      return JSON.stringify(
+        calls.map((call) => ({
+          to: call.to,
+          value: call.value?.toString() ?? '0',
+          data: call.data ?? '0x',
+          gasLimit: call.gasLimit?.toString() ?? '0',
+          delegateCall: call.delegateCall ?? false,
+          onlyFallback: call.onlyFallback ?? false,
+          behaviorOnError: call.behaviorOnError ?? 'revert',
+        })),
+      )
+    } catch (error) {
+      console.warn('ChainSessionManager._fingerprintCalls failed:', error)
+      return null
+    }
+  }
 }