Merge pull request #122 from zerodevapp/feat/fallback-provider

feat: add fallback kernel account client

.env.example

@@ -11,4 +11,12 @@ GREETER_ADDRESS=
 ZERODEV_PROJECT_ID=
 ZERODEV_PAYMASTER_RPC_HOST=
 ZERODEV_BUNDLER_RPC_HOST=
-ZERODEV_API_KEY=
+ZERODEV_API_KEY=
+
+# For fallback e2e tests
+ZERODEV_RPC_URL=
+PIMLICO_RPC_URL=
+STACKUP_RPC_URL=
+ZERODEV_PAYMASTER_RPC_URL=
+PIMLICO_PAYMASTER_RPC_URL=
+STACKUP_PAYMASTER_RPC_URL=

packages/core/clients/fallbackKernelAccountClient.ts

@@ -0,0 +1,62 @@
+import type { EntryPoint } from "permissionless/types"
+import type { Chain, Transport } from "viem"
+import type { KernelSmartAccount } from "../accounts/index.js"
+import type { KernelAccountClient } from "./kernelAccountClient.js"
+
+export const createFallbackKernelAccountClient = <
+    TEntryPoint extends EntryPoint,
+    TTransport extends Transport,
+    TChain extends Chain | undefined,
+    TSmartAccount extends KernelSmartAccount<TEntryPoint> | undefined
+>(
+    clients: Array<
+        KernelAccountClient<TEntryPoint, TTransport, TChain, TSmartAccount>
+    >
+): KernelAccountClient<TEntryPoint, TTransport, TChain, TSmartAccount> => {
+    const proxyClient = new Proxy(clients[0], {
+        get(_target, prop, receiver) {
+            for (const client of clients) {
+                const value = Reflect.get(client, prop, receiver)
+                if (value !== undefined) {
+                    // If the property is a function, wrap it to add fallback logic
+                    if (typeof value === "function") {
+                        // biome-ignore lint/suspicious/noExplicitAny: <explanation>
+                        return async (...args: any[]) => {
+                            for (let i = 0; i < clients.length; i++) {
+                                try {
+                                    const method = Reflect.get(
+                                        clients[i],
+                                        prop,
+                                        receiver
+                                    )
+                                    if (typeof method === "function") {
+                                        // Attempt to call the function on the current client
+                                        return await method(...args)
+                                    }
+                                } catch (error) {
+                                    console.error(
+                                        `Action ${String(
+                                            prop
+                                        )} failed with client ${
+                                            client.transport.url
+                                        }, trying next if available.`,
+                                        error
+                                    )
+                                    if (i === clients.length - 1) {
+                                        throw error
+                                    }
+                                }
+                            }
+                        }
+                    }
+                    // For non-function properties, return the first defined value found
+                    return value
+                }
+            }
+            // If no clients have a defined value for the property, return undefined
+            return undefined
+        }
+    })
+
+    return proxyClient
+}

packages/core/clients/index.ts

@@ -7,3 +7,5 @@ export {
     createKernelAccountClient,
     type KernelAccountClient
 } from "./kernelAccountClient.js"
+
+export { createFallbackKernelAccountClient } from "./fallbackKernelAccountClient.js"

packages/core/index.ts

@@ -26,6 +26,7 @@ export {
     createKernelAccountClient,
     type KernelAccountClient
 } from "./clients/kernelAccountClient.js"
+export { createFallbackKernelAccountClient } from "./clients/fallbackKernelAccountClient.js"
 export {
     type KernelValidator,
     type ZeroDevPaymasterRpcSchema,