feat: Add MM Connect integration

package.json

@@ -102,5 +102,9 @@
       "@solana/web3.js>rpc-websockets>bufferutil": false,
       "@solana/web3.js>rpc-websockets>utf-8-validate": false
     }
+  },
+  "dependencies": {
+    "@metamask/connect": "^0.1.0",
+    "@metamask/connect-multichain": "^0.1.0"
   }
 }

src/sdk/SDK.ts

@@ -1,6 +1,7 @@
 import type { CaipAccountId, CaipChainId, Json } from '@metamask/utils';
 import { parseCaipChainId, parseCaipAccountId } from '@metamask/utils';
 
+import MetaMaskConnectProvider from './providers/MetaMaskConnectProvider';
 import type MetaMaskMultichainBaseProvider from './providers/MetaMaskMultichainBaseProvider';
 import MetaMaskMultichainExternallyConnectableProvider from './providers/MetaMaskMultichainExternallyConnectableProvider';
 import MetaMaskMultichainWindowPostMessageProvider from './providers/MetaMaskMultichainWindowPostMessageProvider';
@@ -113,6 +114,10 @@ export class SDK {
     if (extensionId === WINDOW_POST_MESSAGE_ID) {
       this.#provider = new MetaMaskMultichainWindowPostMessageProvider();
       connected = await this.#provider.connect();
+    } else if (extensionId === 'connect') {
+      this.#provider =
+        new MetaMaskConnectProvider() as unknown as MetaMaskMultichainBaseProvider;
+      connected = await this.#provider.connect();
     } else {
       this.#provider = new MetaMaskMultichainExternallyConnectableProvider();
       connected = await this.#provider.connect(extensionId);

src/sdk/providers/MetaMaskConnectProvider.ts

@@ -0,0 +1,91 @@
+import type { MultichainCore } from '@metamask/connect-multichain';
+import { createMetamaskConnect } from '@metamask/connect-multichain';
+
+import type { Provider } from './Provider';
+
+type NotificationCallback = (notification: any) => void;
+
+class MetaMaskConnectProvider implements Provider {
+  #mmConnect: MultichainCore | null;
+
+  #notificationCallbacks: Set<NotificationCallback> = new Set();
+
+  constructor() {
+    this.#mmConnect = null;
+    this.#notificationCallbacks = new Set();
+  }
+
+  async connect(): Promise<boolean> {
+    if (this.#mmConnect) {
+      this.disconnect();
+    }
+
+    this.#mmConnect = await createMetamaskConnect({
+      dapp: {
+        name: 'MultichainTest Dapp',
+        url: 'https://metamask.github.io/test-dapp-multichain/latest/',
+      },
+      transport: {
+        onNotification: (notification: any) => {
+          this.#notifyCallbacks(notification);
+        },
+      },
+    });
+
+
+    return true;
+  }
+
+  disconnect(): void {
+    if (this.#mmConnect !== null) {
+      this.#mmConnect.disconnect();
+      this.#mmConnect = null;
+    }
+  }
+
+  isConnected(): boolean {
+    return Boolean(this.#mmConnect);
+  }
+
+  async request(request: { method: string; params: any }): Promise<any> {
+    if (request.method === 'wallet_invokeMethod') {
+      return this.#mmConnect?.invokeMethod(request.params);
+    }
+    if (request.method === 'wallet_getSession') {
+      // handle this locally
+    }
+    if (request.method === 'wallet_revokeSession') {
+      // noop?
+    }
+    if (request.method === 'wallet_createSession') {
+      await this.#mmConnect?.connect(['eip155:1'], []);
+    }
+    return Promise.resolve(null);
+  }
+
+  onNotification(callback: NotificationCallback): void {
+    this.#notificationCallbacks.add(callback);
+  }
+
+  removeNotificationListener(callback: NotificationCallback): void {
+    this.#notificationCallbacks.delete(callback);
+  }
+
+  removeAllNotificationListeners() {
+    this.#notificationCallbacks.forEach(
+      this.removeNotificationListener.bind(this),
+    );
+  }
+
+  #notifyCallbacks(notification: any): void {
+    this.#notificationCallbacks.forEach((callback) => {
+      try {
+        callback(notification);
+      } catch (error) {
+        console.error('Error in notification callback:', error);
+      }
+    });
+  }
+}
+
+export default MetaMaskConnectProvider;