diff --git a/.github/workflows/cli-integration-test.yml b/.github/workflows/cli-integration-test.yml
deleted file mode 100644
index f325e10..0000000
--- a/.github/workflows/cli-integration-test.yml
+++ /dev/null
@@ -1,65 +0,0 @@
-name: CLI Integration Test
-
-on:
-  push:
-  pull_request:
-    branches: [ main ]
-  workflow_dispatch:
-
-jobs:
-  cli-integration:
-    runs-on: ubuntu-latest
-    timeout-minutes: 10
-
-    steps:
-    - name: Checkout repository
-      uses: actions/checkout@v4
-
-    - name: Install pnpm
-      uses: pnpm/action-setup@v4
-
-    - name: Setup Node.js
-      uses: actions/setup-node@v4
-      with:
-        node-version: '20.x'
-        cache: 'pnpm'
-
-    - name: Install dependencies
-      run: pnpm install --frozen-lockfile
-
-    - name: Build CLI
-      run: pnpm run build
-
-    - name: Clone test project
-      run: git clone https://github.com/wokwi/esp-idf-hello-world.git test-project
-
-    - name: Create test scenario
-      run: |
-        cat > test-project/test-scenario.yaml << 'EOF'
-        name: "Basic Hello World Test"
-        version: 1
-        description: "Test that the ESP32 hello world program outputs expected text"
-
-        steps:
-          - name: "Wait for boot and hello message"
-            wait-serial: "Hello world!"
-
-          - name: "Wait for chip information"
-            wait-serial: "This is esp32 chip"
-
-          - name: "Wait for restart message"
-            wait-serial: "Restarting in 10 seconds"
-        EOF
-
-    - name: Run a Wokwi CI server
-      uses: wokwi/wokwi-ci-server-action@v1
-
-    - name: Test CLI with basic expect-text
-      run: pnpm cli test-project --timeout 5000 --expect-text "Hello"
-      env:
-        WOKWI_CLI_TOKEN: ${{ secrets.WOKWI_CLI_TOKEN }}
-
-    - name: Test CLI with scenario file
-      run: pnpm cli test-project --scenario test-scenario.yaml --timeout 15000
-      env:
-        WOKWI_CLI_TOKEN: ${{ secrets.WOKWI_CLI_TOKEN }}
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 49c1cac..24986af 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -2,9 +2,9 @@ name: Tests
 
 on:
   push:
-    branches: [main]
   pull_request:
     branches: [main]
+  workflow_dispatch:
 
 jobs:
   test:
@@ -20,5 +20,15 @@ jobs:
           cache: 'pnpm'
       - name: Install dependencies
         run: pnpm install --frozen-lockfile
-      - name: Run tests
-        run: pnpm test
+      - name: Build packages
+        run: pnpm run build
+      - name: Install Playwright browsers
+        run: pnpm exec playwright install --with-deps
+      - name: Run vitest tests
+        run: pnpm run test:vitest
+      - name: Run Playwright embed tests
+        run: pnpm run test:embed:playwright
+      - name: Run CLI integration tests
+        run: pnpm run test:cli:integration
+        env:
+          WOKWI_CLI_TOKEN: ${{ secrets.WOKWI_CLI_TOKEN }}
diff --git a/.gitignore b/.gitignore
index 58c63ed..4ea6eee 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,6 @@ wokwi.toml
 *.bin
 diagram.json
 screenshot.png
+playwright-report/
+test-results/
+test-project/
diff --git a/eslint.config.ts b/eslint.config.ts
index 7480f37..13482f9 100644
--- a/eslint.config.ts
+++ b/eslint.config.ts
@@ -18,6 +18,8 @@ export default defineConfig(
       '**/.git/**',
       '**/coverage/**',
       '**/*.min.js',
+      '**/playwright-report/**',
+      '**/test-results/**',
     ],
   },
 
diff --git a/package.json b/package.json
index 2281752..0710a0a 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,11 @@
     "clean": "pnpm -r run clean",
     "lint": "eslint .",
     "lint:fix": "eslint . --fix",
-    "test": "npm run lint && vitest --run",
+    "test": "pnpm run test:vitest && pnpm run test:embed:playwright && pnpm run test:cli:integration",
+    "test:vitest": "pnpm run lint && vitest --run",
+    "test:embed:playwright": "playwright test test/wokwi-embed",
+    "test:embed:playwright:ui": "playwright test test/wokwi-embed --ui",
+    "test:cli:integration": "bash scripts/test-cli-integration.sh",
     "cli": "tsx packages/wokwi-cli/src/main.ts",
     "prepare": "husky install"
   },
@@ -19,19 +23,9 @@
     "type": "git",
     "url": "https://github.com/wokwi/wokwi-cli"
   },
-  "dependencies": {
-    "@clack/prompts": "^0.7.0",
-    "@iarna/toml": "2.2.5",
-    "@modelcontextprotocol/sdk": "^1.0.0",
-    "arg": "^5.0.2",
-    "chalk": "^5.3.0",
-    "chalk-template": "^1.1.0",
-    "pngjs": "^7.0.0",
-    "ws": "^8.13.0",
-    "yaml": "^2.3.1"
-  },
   "devDependencies": {
     "@eslint/js": "^9.39.1",
+    "@playwright/test": "^1.48.0",
     "esbuild": "^0.25.2",
     "eslint": "^9.39.1",
     "eslint-config-prettier": "^10.1.8",
diff --git a/packages/wokwi-cli/package.json b/packages/wokwi-cli/package.json
index 1799eef..7b7860b 100644
--- a/packages/wokwi-cli/package.json
+++ b/packages/wokwi-cli/package.json
@@ -5,10 +5,15 @@
   "main": "index.js",
   "type": "module",
   "scripts": {
-    "build": "node tools/build.js",
-    "package": "npm run build && pkg --public -o dist/bin/wokwi-cli -t node20-linuxstatic-arm64,node20-linuxstatic-x64,node20-macos-arm64,node20-macos-x64,node20-win-x64 dist/cli.cjs",
+    "prebuild": "pnpm run clean",
+    "build": "tsc && pnpm run bundle",
+    "bundle": "node tools/bundle.js",
+    "package": "pnpm run build && pkg --public -o dist/bin/wokwi-cli -t node20-linuxstatic-arm64,node20-linuxstatic-x64,node20-macos-arm64,node20-macos-x64,node20-win-x64 dist/cli.cjs",
+    "clean": "rimraf dist",
+    "lint": "eslint src/**/*.ts",
+    "lint:fix": "eslint src/**/*.ts --fix",
     "cli": "tsx src/main.ts",
-    "test": "npm run lint && vitest --run",
+    "test": "pnpm run lint && vitest --run",
     "test:watch": "vitest --watch"
   },
   "keywords": [
@@ -41,6 +46,7 @@
     "chalk": "^5.3.0",
     "chalk-template": "^1.1.0",
     "pngjs": "^7.0.0",
+    "wokwi-client-js": "workspace:*",
     "ws": "^8.13.0",
     "yaml": "^2.3.1"
   },
diff --git a/packages/wokwi-cli/src/TestScenario.ts b/packages/wokwi-cli/src/TestScenario.ts
index 2dda74b..d7077a3 100644
--- a/packages/wokwi-cli/src/TestScenario.ts
+++ b/packages/wokwi-cli/src/TestScenario.ts
@@ -1,5 +1,5 @@
 import chalkTemplate from 'chalk-template';
-import type { APIClient } from './APIClient.js';
+import type { APIClient } from 'wokwi-client-js';
 
 export interface IScenarioCommand {
   /** Validates the input to the command. Throws an exception of the input is not valid */
diff --git a/packages/wokwi-cli/src/constants.ts b/packages/wokwi-cli/src/constants.ts
new file mode 100644
index 0000000..cf20405
--- /dev/null
+++ b/packages/wokwi-cli/src/constants.ts
@@ -0,0 +1,2 @@
+export const DEFAULT_SERVER = process.env.WOKWI_CLI_SERVER ?? 'wss://wokwi.com/api/ws/beta';
+
diff --git a/packages/wokwi-cli/src/main.ts b/packages/wokwi-cli/src/main.ts
index f92a7ca..dbe9dca 100644
--- a/packages/wokwi-cli/src/main.ts
+++ b/packages/wokwi-cli/src/main.ts
@@ -3,8 +3,9 @@ import chalkTemplate from 'chalk-template';
 import { createWriteStream, existsSync, readFileSync, writeFileSync } from 'fs';
 import path, { join } from 'path';
 import YAML from 'yaml';
-import { APIClient } from './APIClient.js';
-import type { APIEvent, ChipsLogPayload, SerialMonitorDataPayload } from './APITypes.js';
+import { APIClient, type APIEvent, type ChipsLogPayload, type SerialMonitorDataPayload } from 'wokwi-client-js';
+import { WebSocketTransport } from './transport/WebSocketTransport.js';
+import { DEFAULT_SERVER } from './constants.js';
 import { ExpectEngine } from './ExpectEngine.js';
 import { SimulationTimeoutError } from './SimulationTimeoutError.js';
 import { TestScenario } from './TestScenario.js';
@@ -22,41 +23,42 @@ import { TakeScreenshotCommand } from './scenario/TakeScreenshotCommand.js';
 import { WaitSerialCommand } from './scenario/WaitSerialCommand.js';
 import { WriteSerialCommand } from './scenario/WriteSerialCommand.js';
 import { uploadFirmware } from './uploadFirmware.js';
+const { sha, version } = readVersion();
 
 const millis = 1_000_000;
 
 function printVersion(short = false) {
   const { sha, version } = readVersion();
   if (short) {
-    console.log(`${version} (${sha})`);
+	console.log(`${version} (${sha})`);
   } else {
-    console.log(`Wokwi CLI v${version} (${sha})`);
+	console.log(`Wokwi CLI v${version} (${sha})`);
   }
 }
 
 async function main() {
   const args = arg(
-    {
-      '--help': Boolean,
-      '--quiet': Boolean,
-      '--version': Boolean,
-      '--short-version': Boolean,
-      '--diagram-file': String,
-      '--elf': String,
-      '--expect-text': String,
-      '--fail-text': String,
-      '--interactive': Boolean,
-      '--serial-log-file': String,
-      '--scenario': String,
-      '--screenshot-part': String,
-      '--screenshot-file': String,
-      '--screenshot-time': Number,
-      '--timeout': Number,
-      '--timeout-exit-code': Number,
-      '-h': '--help',
-      '-q': '--quiet',
-    },
-    { argv: process.argv.slice(2) },
+	{
+	  '--help': Boolean,
+	  '--quiet': Boolean,
+	  '--version': Boolean,
+	  '--short-version': Boolean,
+	  '--diagram-file': String,
+	  '--elf': String,
+	  '--expect-text': String,
+	  '--fail-text': String,
+	  '--interactive': Boolean,
+	  '--serial-log-file': String,
+	  '--scenario': String,
+	  '--screenshot-part': String,
+	  '--screenshot-file': String,
+	  '--screenshot-time': Number,
+	  '--timeout': Number,
+	  '--timeout-exit-code': Number,
+	  '-h': '--help',
+	  '-q': '--quiet',
+	},
+	{ argv: process.argv.slice(2) },
   );
 
   const quiet = args['--quiet'];
@@ -75,51 +77,51 @@ async function main() {
   const timeoutNanos = timeout * millis;
 
   if (args['--version'] === true || args['--short-version'] === true) {
-    printVersion(args['--short-version']);
-    process.exit(0);
+	printVersion(args['--short-version']);
+	process.exit(0);
   }
 
   if (!quiet) {
-    printVersion();
+	printVersion();
   }
 
   if (args['--help']) {
-    cliHelp();
-    process.exit(0);
+	cliHelp();
+	process.exit(0);
   }
 
   if (args._[0] === 'init') {
-    await initProjectWizard(args._[1] ?? '.', { diagramFile });
-    process.exit(0);
+	await initProjectWizard(args._[1] ?? '.', { diagramFile });
+	process.exit(0);
   }
 
   const token = process.env.WOKWI_CLI_TOKEN;
   if (token == null || token.length === 0) {
-    console.error(
-      chalkTemplate`{red Error:} Missing {yellow WOKWI_CLI_TOKEN} environment variable. Please set it to your Wokwi token.\nGet your token at {yellow https://wokwi.com/dashboard/ci}.`,
-    );
-    process.exit(1);
+	console.error(
+	  chalkTemplate`{red Error:} Missing {yellow WOKWI_CLI_TOKEN} environment variable. Please set it to your Wokwi token.\nGet your token at {yellow https://wokwi.com/dashboard/ci}.`,
+	);
+	process.exit(1);
   }
 
   if (args._[0] === 'mcp') {
-    const rootDir = args._[1] || '.';
+	const rootDir = args._[1] || '.';
 
-    const mcpServer = new WokwiMCPServer({ rootDir, token, quiet });
+	const mcpServer = new WokwiMCPServer({ rootDir, token, quiet });
 
-    process.on('SIGINT', () => {
-      void mcpServer.stop().then(() => {
-        process.exit(0);
-      });
-    });
+	process.on('SIGINT', () => {
+	  void mcpServer.stop().then(() => {
+		process.exit(0);
+	  });
+	});
 
-    process.on('SIGTERM', () => {
-      void mcpServer.stop().then(() => {
-        process.exit(0);
-      });
-    });
+	process.on('SIGTERM', () => {
+	  void mcpServer.stop().then(() => {
+		process.exit(0);
+	  });
+	});
 
-    await mcpServer.start();
-    return;
+	await mcpServer.start();
+	return;
   }
 
   const rootDir = args._[0] || '.';
@@ -128,51 +130,51 @@ async function main() {
   const espIdfFlasherArgsPath = path.resolve(rootDir, 'build/flasher_args.json');
   const espIdfProjectDescriptionPath = path.resolve(rootDir, 'build/project_description.json');
   const isIDFProject =
-    existsSync(espIdfFlasherArgsPath) && existsSync(espIdfProjectDescriptionPath);
+	existsSync(espIdfFlasherArgsPath) && existsSync(espIdfProjectDescriptionPath);
   let configExists = existsSync(configPath);
   let diagramExists = existsSync(diagramFilePath);
 
   if (isIDFProject) {
-    if (!quiet) {
-      console.log(`Detected IDF project in ${rootDir}`);
-    }
-    if (
-      !idfProjectConfig({
-        rootDir,
-        configPath,
-        diagramFilePath,
-        projectDescriptionPath: espIdfProjectDescriptionPath,
-        createConfig: !configExists,
-        createDiagram: !diagramExists,
-        quiet,
-      })
-    ) {
-      process.exit(1);
-    }
-    configExists = true;
-    diagramExists = true;
+	if (!quiet) {
+	  console.log(`Detected IDF project in ${rootDir}`);
+	}
+	if (
+	  !idfProjectConfig({
+		rootDir,
+		configPath,
+		diagramFilePath,
+		projectDescriptionPath: espIdfProjectDescriptionPath,
+		createConfig: !configExists,
+		createDiagram: !diagramExists,
+		quiet,
+	  })
+	) {
+	  process.exit(1);
+	}
+	configExists = true;
+	diagramExists = true;
   }
 
   if (!elf && !configExists) {
-    console.error(
-      chalkTemplate`{red Error:} {yellow wokwi.toml} not found in {yellow ${path.resolve(
-        rootDir,
-      )}}.`,
-    );
-    console.error(
-      chalkTemplate`Run \`{green wokwi-cli init}\` to automatically create a {yellow wokwi.toml} file.`,
-    );
-    process.exit(1);
+	console.error(
+	  chalkTemplate`{red Error:} {yellow wokwi.toml} not found in {yellow ${path.resolve(
+		rootDir,
+	  )}}.`,
+	);
+	console.error(
+	  chalkTemplate`Run \`{green wokwi-cli init}\` to automatically create a {yellow wokwi.toml} file.`,
+	);
+	process.exit(1);
   }
 
   if (!existsSync(diagramFilePath)) {
-    console.error(
-      chalkTemplate`{red Error:} {yellow diagram.json} not found in {yellow ${diagramFilePath}}.`,
-    );
-    console.error(
-      chalkTemplate`Run \`{green wokwi-cli init}\` to automatically create a {yellow diagram.json} file.`,
-    );
-    process.exit(1);
+	console.error(
+	  chalkTemplate`{red Error:} {yellow diagram.json} not found in {yellow ${diagramFilePath}}.`,
+	);
+	console.error(
+	  chalkTemplate`Run \`{green wokwi-cli init}\` to automatically create a {yellow diagram.json} file.`,
+	);
+	process.exit(1);
   }
 
   let firmwarePath;
@@ -180,37 +182,37 @@ async function main() {
   let config;
 
   if (configExists) {
-    const configData = readFileSync(configPath, 'utf8');
-    config = await parseConfig(configData, rootDir);
+	const configData = readFileSync(configPath, 'utf8');
+	config = await parseConfig(configData, rootDir);
 
-    firmwarePath = elf ?? join(rootDir, config.wokwi.firmware);
-    const configElfPath = config.wokwi.elf ? join(rootDir, config.wokwi.elf) : undefined;
-    elfPath = elf ?? configElfPath;
+	firmwarePath = elf ?? join(rootDir, config.wokwi.firmware);
+	const configElfPath = config.wokwi.elf ? join(rootDir, config.wokwi.elf) : undefined;
+	elfPath = elf ?? configElfPath;
   } else if (elf) {
-    firmwarePath = elf;
-    elfPath = elf;
+	firmwarePath = elf;
+	elfPath = elf;
   } else {
-    throw new Error('Internal error: neither elf nor config exists');
+	throw new Error('Internal error: neither elf nor config exists');
   }
 
   if (!existsSync(firmwarePath)) {
-    const fullPath = path.resolve(firmwarePath);
-    console.error(
-      chalkTemplate`{red Error:} {yellow firmware file} not found: {yellow ${fullPath}}.`,
-    );
-    console.error(
-      chalkTemplate`Please check the {yellow firmware} path in your {yellow wokwi.toml} configuration file.`,
-    );
-    process.exit(1);
+	const fullPath = path.resolve(firmwarePath);
+	console.error(
+	  chalkTemplate`{red Error:} {yellow firmware file} not found: {yellow ${fullPath}}.`,
+	);
+	console.error(
+	  chalkTemplate`Please check the {yellow firmware} path in your {yellow wokwi.toml} configuration file.`,
+	);
+	process.exit(1);
   }
 
   if (elfPath != null && !existsSync(elfPath)) {
-    const fullPath = path.resolve(elfPath);
-    console.error(chalkTemplate`{red Error:} ELF file not found: {yellow ${fullPath}}.`);
-    console.error(
-      chalkTemplate`Please check the {yellow elf} path in your {yellow wokwi.toml} configuration file.`,
-    );
-    process.exit(1);
+	const fullPath = path.resolve(elfPath);
+	console.error(chalkTemplate`{red Error:} ELF file not found: {yellow ${fullPath}}.`);
+	console.error(
+	  chalkTemplate`Please check the {yellow elf} path in your {yellow wokwi.toml} configuration file.`,
+	);
+	process.exit(1);
   }
 
   const diagram = readFileSync(diagramFilePath, 'utf8');
@@ -219,172 +221,173 @@ async function main() {
 
   const resolvedScenarioFile = scenarioFile ? path.resolve(rootDir, scenarioFile) : null;
   if (resolvedScenarioFile && !existsSync(resolvedScenarioFile)) {
-    const fullPath = path.resolve(resolvedScenarioFile);
-    console.error(chalkTemplate`{red Error:} scenario file not found: {yellow ${fullPath}}.`);
-    process.exit(1);
+	const fullPath = path.resolve(resolvedScenarioFile);
+	console.error(chalkTemplate`{red Error:} scenario file not found: {yellow ${fullPath}}.`);
+	process.exit(1);
   }
 
   const expectEngine = new ExpectEngine();
 
   let scenario: TestScenario | undefined;
   if (resolvedScenarioFile) {
-    scenario = new TestScenario(YAML.parse(readFileSync(resolvedScenarioFile, 'utf-8')));
-    scenario.registerCommands({
-      delay: new DelayCommand(),
-      'expect-pin': new ExpectPinCommand(),
-      'set-control': new SetControlCommand(),
-      'wait-serial': new WaitSerialCommand(),
-      'write-serial': new WriteSerialCommand(),
-      'take-screenshot': new TakeScreenshotCommand(path.dirname(resolvedScenarioFile)),
-    });
-    scenario.validate();
+	scenario = new TestScenario(YAML.parse(readFileSync(resolvedScenarioFile, 'utf-8')));
+	scenario.registerCommands({
+	  delay: new DelayCommand(),
+	  'expect-pin': new ExpectPinCommand(),
+	  'set-control': new SetControlCommand(),
+	  'wait-serial': new WaitSerialCommand(),
+	  'write-serial': new WriteSerialCommand(),
+	  'take-screenshot': new TakeScreenshotCommand(path.dirname(resolvedScenarioFile)),
+	});
+	scenario.validate();
   }
 
   const serialLogStream = serialLogFile ? createWriteStream(serialLogFile) : null;
 
   if (expectText) {
-    expectEngine.expectTexts.push(expectText);
-    expectEngine.on('match', (text) => {
-      if (text !== expectText) {
-        return;
-      }
-
-      if (!quiet) {
-        console.log(chalkTemplate`\n\nExpected text found: {green "${expectText}"}`);
-        console.log('TEST PASSED.');
-      }
-      client.close();
-      process.exit(0);
-    });
+	expectEngine.expectTexts.push(expectText);
+	expectEngine.on('match', (text) => {
+	  if (text !== expectText) {
+		return;
+	  }
+
+	  if (!quiet) {
+		console.log(chalkTemplate`\n\nExpected text found: {green "${expectText}"}`);
+		console.log('TEST PASSED.');
+	  }
+	  client.close();
+	  process.exit(0);
+	});
   }
 
   if (failText) {
-    expectEngine.failTexts.push(failText);
-    expectEngine.on('fail', (text) => {
-      if (text !== failText) {
-        return;
-      }
-
-      console.error(chalkTemplate`\n\n{red Error:} Unexpected text found: {yellow "${text}"}`);
-      console.error('TEST FAILED.');
-      client.close();
-      process.exit(1);
-    });
+	expectEngine.failTexts.push(failText);
+	expectEngine.on('fail', (text) => {
+	  if (text !== failText) {
+		return;
+	  }
+
+	  console.error(chalkTemplate`\n\n{red Error:} Unexpected text found: {yellow "${text}"}`);
+	  console.error('TEST FAILED.');
+	  client.close();
+	  process.exit(1);
+	});
   }
-
-  const client = new APIClient(token);
+  
+  const transport = new WebSocketTransport(token, DEFAULT_SERVER, version, sha);
+  const client = new APIClient(transport);
   client.onConnected = (hello) => {
-    if (!quiet) {
-      console.log(`Connected to Wokwi Simulation API ${hello.appVersion}`);
-    }
+	if (!quiet) {
+	  console.log(`Connected to Wokwi Simulation API ${hello.appVersion}`);
+	}
   };
   client.onError = (error) => {
-    console.error('API Error:', error.message);
-    process.exit(1);
+	console.error('API Error:', error.message);
+	process.exit(1);
   };
 
   try {
-    await client.connected;
-    await client.fileUpload('diagram.json', diagram);
-    const firmwareName = await uploadFirmware(client, firmwarePath);
-    if (elfPath != null) {
-      await client.fileUpload('firmware.elf', readFileSync(elfPath));
-    }
-
-    for (const chip of chips) {
-      await client.fileUpload(`${chip.name}.chip.json`, readFileSync(chip.jsonPath, 'utf-8'));
-      await client.fileUpload(`${chip.name}.chip.wasm`, readFileSync(chip.wasmPath));
-    }
-
-    const promises = [];
-    let screenshotPromise = Promise.resolve();
-
-    if (screenshotPart != null && screenshotTime != null) {
-      if (timeout && screenshotTime > timeout) {
-        console.error(
-          chalkTemplate`{red Error:} Screenshot time (${screenshotTime}ms) can't be greater than the timeout (${timeout}ms).`,
-        );
-        process.exit(1);
-      }
-      screenshotPromise = client.atNanos(screenshotTime * millis).then(async () => {
-        try {
-          const result = await client.framebufferRead(screenshotPart);
-          writeFileSync(screenshotFile, result.png, 'base64');
-          await client.simResume();
-        } catch (err) {
-          console.error('Error taking screenshot:', (err as Error).toString());
-          throw err;
-        }
-      });
-    }
-
-    if (!quiet) {
-      console.log('Starting simulation...');
-    }
-
-    await client.serialMonitorListen();
-
-    client.listen('serial-monitor:data', (event: APIEvent<SerialMonitorDataPayload>) => {
-      let { bytes } = event.payload;
-      bytes = scenario?.processSerialBytes(bytes) ?? bytes;
-      process.stdout.write(new Uint8Array(bytes));
-
-      serialLogStream?.write(Buffer.from(bytes));
-      expectEngine.feed(bytes);
-    });
-
-    client.listen('chips:log', (event: APIEvent<ChipsLogPayload>) => {
-      const { message, chip } = event.payload;
-      console.log(chalkTemplate`[{magenta ${chip}}] ${message}`);
-    });
-
-    if (timeoutNanos) {
-      promises.push(
-        client.atNanos(timeoutNanos).then(async () => {
-          await screenshotPromise; // wait for the screenshot to be saved, if any
-          console.error(chalkTemplate`\n{red Timeout}: simulation did not finish in ${timeout}ms`);
-          throw new SimulationTimeoutError(
-            timeoutExitCode,
-            `simulation did not finish in ${timeout}ms`,
-          );
-        }),
-      );
-    }
-
-    await client.simStart({
-      firmware: firmwareName,
-      elf: elfPath != null ? 'firmware.elf' : undefined,
-      chips: chips.map((chip) => chip.name),
-      pause: scenario != null,
-    });
-
-    if (interactive) {
-      process.stdin.pipe(client.serialMonitorWritable());
-    }
-
-    if (scenario != null) {
-      promises.push(scenario.start(client));
-    } else {
-      await client.simResume();
-    }
-
-    if (promises.length === 0) {
-      // wait forever
-      await new Promise(() => {});
-    }
-
-    // wait until the scenario finishes or a timeout occurs
-    await Promise.race(promises);
-    // wait for the screenshot to be saved, if any
-    await screenshotPromise;
+	await client.connected;
+	await client.fileUpload('diagram.json', diagram);
+	const firmwareName = await uploadFirmware(client, firmwarePath);
+	if (elfPath != null) {
+	  await client.fileUpload('firmware.elf', new Uint8Array(readFileSync(elfPath)));
+	}
+
+	for (const chip of chips) {
+	  await client.fileUpload(`${chip.name}.chip.json`, readFileSync(chip.jsonPath, 'utf-8'));
+	  await client.fileUpload(`${chip.name}.chip.wasm`, new Uint8Array(readFileSync(chip.wasmPath)));
+	}
+
+	const promises = [];
+	let screenshotPromise = Promise.resolve();
+
+	if (screenshotPart != null && screenshotTime != null) {
+	  if (timeout && screenshotTime > timeout) {
+		console.error(
+		  chalkTemplate`{red Error:} Screenshot time (${screenshotTime}ms) can't be greater than the timeout (${timeout}ms).`,
+		);
+		process.exit(1);
+	  }
+	  screenshotPromise = client.atNanos(screenshotTime * millis).then(async () => {
+		try {
+		  const result = await client.framebufferRead(screenshotPart);
+		  writeFileSync(screenshotFile, result.png, 'base64');
+		  await client.simResume();
+		} catch (err) {
+		  console.error('Error taking screenshot:', (err as Error).toString());
+		  throw err;
+		}
+	  });
+	}
+
+	if (!quiet) {
+	  console.log('Starting simulation...');
+	}
+
+	await client.serialMonitorListen();
+
+	client.listen('serial-monitor:data', (event: APIEvent<SerialMonitorDataPayload>) => {
+	  let { bytes } = event.payload;
+	  bytes = scenario?.processSerialBytes(bytes) ?? bytes;
+	  process.stdout.write(new Uint8Array(bytes));
+
+	  serialLogStream?.write(Buffer.from(bytes));
+	  expectEngine.feed(bytes);
+	});
+
+	client.listen('chips:log', (event: APIEvent<ChipsLogPayload>) => {
+	  const { message, chip } = event.payload;
+	  console.log(chalkTemplate`[{magenta ${chip}}] ${message}`);
+	});
+
+	if (timeoutNanos) {
+	  promises.push(
+		client.atNanos(timeoutNanos).then(async () => {
+		  await screenshotPromise; // wait for the screenshot to be saved, if any
+		  console.error(chalkTemplate`\n{red Timeout}: simulation did not finish in ${timeout}ms`);
+		  throw new SimulationTimeoutError(
+			timeoutExitCode,
+			`simulation did not finish in ${timeout}ms`,
+		  );
+		}),
+	  );
+	}
+
+	await client.simStart({
+	  firmware: firmwareName,
+	  elf: elfPath != null ? 'firmware.elf' : undefined,
+	  chips: chips.map((chip) => chip.name),
+	  pause: scenario != null,
+	});
+
+	if (interactive) {
+	  process.stdin.pipe(await client.serialMonitorWritable());
+	}
+
+	if (scenario != null) {
+	  promises.push(scenario.start(client));
+	} else {
+	  await client.simResume();
+	}
+
+	if (promises.length === 0) {
+	  // wait forever
+	  await new Promise(() => {});
+	}
+
+	// wait until the scenario finishes or a timeout occurs
+	await Promise.race(promises);
+	// wait for the screenshot to be saved, if any
+	await screenshotPromise;
   } finally {
-    client.close();
+	client.close();
   }
 }
 
 main().catch((err) => {
   if (err instanceof SimulationTimeoutError) {
-    process.exit(err.exitCode);
+	process.exit(err.exitCode);
   }
   console.error(err);
   process.exit(1);
diff --git a/packages/wokwi-cli/src/mcp/SimulationManager.ts b/packages/wokwi-cli/src/mcp/SimulationManager.ts
index 1962ae5..5603695 100644
--- a/packages/wokwi-cli/src/mcp/SimulationManager.ts
+++ b/packages/wokwi-cli/src/mcp/SimulationManager.ts
@@ -1,9 +1,11 @@
 import { existsSync, readFileSync } from 'fs';
 import path from 'path';
-import { APIClient } from '../APIClient.js';
-import type { APIEvent } from '../APITypes.js';
+import { APIClient, type APIEvent } from 'wokwi-client-js';
+import { WebSocketTransport } from '../transport/WebSocketTransport.js';
+import { DEFAULT_SERVER } from '../constants.js';
 import { parseConfig } from '../config.js';
 import { loadChips } from '../loadChips.js';
+import { readVersion } from '../readVersion.js';
 import { uploadFirmware } from '../uploadFirmware.js';
 
 export interface SimulationStatus {
@@ -31,7 +33,9 @@ export class SimulationManager {
       return;
     }
 
-    this.client = new APIClient(this.token);
+    const { sha, version } = readVersion();
+    const transport = new WebSocketTransport(this.token, DEFAULT_SERVER, version, sha);
+    this.client = new APIClient(transport);
 
     this.client.onConnected = (hello) => {
       this.isConnected = true;
@@ -104,12 +108,12 @@ export class SimulationManager {
     const firmwareName = await uploadFirmware(this.client, firmwarePath);
 
     if (elfPath) {
-      await this.client.fileUpload('firmware.elf', readFileSync(elfPath));
+      await this.client.fileUpload('firmware.elf', new Uint8Array(readFileSync(elfPath)));
     }
 
     for (const chip of chips) {
       await this.client.fileUpload(`${chip.name}.chip.json`, readFileSync(chip.jsonPath, 'utf-8'));
-      await this.client.fileUpload(`${chip.name}.chip.wasm`, readFileSync(chip.wasmPath));
+      await this.client.fileUpload(`${chip.name}.chip.wasm`, new Uint8Array(readFileSync(chip.wasmPath)));
     }
 
     // Start simulation
diff --git a/packages/wokwi-cli/src/project/projectType.ts b/packages/wokwi-cli/src/project/projectType.ts
index 4186b51..42128ff 100644
--- a/packages/wokwi-cli/src/project/projectType.ts
+++ b/packages/wokwi-cli/src/project/projectType.ts
@@ -25,7 +25,7 @@ export async function detectProjectType(root: string): Promise<ProjectType | nul
 
   const cmakeLists = await readFileOrNull(join(root, 'CMakeLists.txt'));
   if (cmakeLists) {
-    const cmakeListStr = Buffer.from(cmakeLists).toString();
+    const cmakeListStr = cmakeLists.toString('utf-8');
     if (cmakeListStr.includes('$ENV{IDF_PATH}')) {
       return 'esp-idf';
     }
diff --git a/packages/wokwi-cli/src/scenario/DelayCommand.ts b/packages/wokwi-cli/src/scenario/DelayCommand.ts
index 37e2055..15e8268 100644
--- a/packages/wokwi-cli/src/scenario/DelayCommand.ts
+++ b/packages/wokwi-cli/src/scenario/DelayCommand.ts
@@ -1,5 +1,5 @@
 import chalkTemplate from 'chalk-template';
-import { type APIClient } from '../APIClient.js';
+import { type APIClient } from 'wokwi-client-js';
 import { type TestScenario } from '../TestScenario.js';
 import { parseTime } from '../utils/parseTime.js';
 
diff --git a/packages/wokwi-cli/src/scenario/ExpectPinCommand.ts b/packages/wokwi-cli/src/scenario/ExpectPinCommand.ts
index 20f53f0..6fbe39c 100644
--- a/packages/wokwi-cli/src/scenario/ExpectPinCommand.ts
+++ b/packages/wokwi-cli/src/scenario/ExpectPinCommand.ts
@@ -1,5 +1,5 @@
 import chalkTemplate from 'chalk-template';
-import type { APIClient } from '../APIClient.js';
+import type { APIClient } from 'wokwi-client-js';
 import type { IScenarioCommand, TestScenario } from '../TestScenario.js';
 
 export interface IExpectPinParams {
diff --git a/packages/wokwi-cli/src/scenario/SetControlCommand.ts b/packages/wokwi-cli/src/scenario/SetControlCommand.ts
index 0767dda..88de89a 100644
--- a/packages/wokwi-cli/src/scenario/SetControlCommand.ts
+++ b/packages/wokwi-cli/src/scenario/SetControlCommand.ts
@@ -1,4 +1,4 @@
-import { type APIClient } from '../APIClient.js';
+import { type APIClient } from 'wokwi-client-js';
 import { type TestScenario } from '../TestScenario.js';
 
 export interface ISetControlParams {
diff --git a/packages/wokwi-cli/src/scenario/TakeScreenshotCommand.ts b/packages/wokwi-cli/src/scenario/TakeScreenshotCommand.ts
index f9bd84d..abb303b 100644
--- a/packages/wokwi-cli/src/scenario/TakeScreenshotCommand.ts
+++ b/packages/wokwi-cli/src/scenario/TakeScreenshotCommand.ts
@@ -1,7 +1,7 @@
 import { readFile, writeFile } from 'fs/promises';
 import path from 'path';
 import { PNG } from 'pngjs';
-import { type APIClient } from '../APIClient.js';
+import { base64ToByteArray, type APIClient } from 'wokwi-client-js';
 import { type TestScenario } from '../TestScenario.js';
 
 export interface ITakeScreenshotParams {
@@ -24,7 +24,7 @@ export class TakeScreenshotCommand {
 
   async run(scenario: TestScenario, client: APIClient, params: ITakeScreenshotParams) {
     const framebuffer = await client.framebufferRead(params['part-id']);
-    const png = Buffer.from(framebuffer.png, 'base64');
+    const png = base64ToByteArray(framebuffer.png);
     const saveTo = params['save-to'];
     const compareWith = params['compare-with'];
     if (saveTo) {
@@ -32,7 +32,7 @@ export class TakeScreenshotCommand {
     }
     if (compareWith) {
       const compareWithPath = path.join(this.scenarioDir, compareWith);
-      const originalPng = PNG.sync.read(png);
+      const originalPng = PNG.sync.read(Buffer.from(png));
 
       let compareWithData;
       try {
diff --git a/packages/wokwi-cli/src/scenario/WaitSerialCommand.ts b/packages/wokwi-cli/src/scenario/WaitSerialCommand.ts
index febdc41..e606e9e 100644
--- a/packages/wokwi-cli/src/scenario/WaitSerialCommand.ts
+++ b/packages/wokwi-cli/src/scenario/WaitSerialCommand.ts
@@ -1,5 +1,5 @@
 import chalkTemplate from 'chalk-template';
-import type { APIClient } from '../APIClient.js';
+import type { APIClient } from 'wokwi-client-js';
 import type { IScenarioCommand, TestScenario } from '../TestScenario.js';
 
 const encoder = new TextEncoder();
diff --git a/packages/wokwi-cli/src/scenario/WriteSerialCommand.ts b/packages/wokwi-cli/src/scenario/WriteSerialCommand.ts
index ca8d4e2..a4f1a25 100644
--- a/packages/wokwi-cli/src/scenario/WriteSerialCommand.ts
+++ b/packages/wokwi-cli/src/scenario/WriteSerialCommand.ts
@@ -1,4 +1,4 @@
-import type { APIClient } from '../APIClient.js';
+import type { APIClient } from 'wokwi-client-js';
 import type { IScenarioCommand, TestScenario } from '../TestScenario.js';
 
 const encoder = new TextEncoder();
diff --git a/packages/wokwi-cli/src/transport/WebSocketTransport.ts b/packages/wokwi-cli/src/transport/WebSocketTransport.ts
new file mode 100644
index 0000000..bcf95fa
--- /dev/null
+++ b/packages/wokwi-cli/src/transport/WebSocketTransport.ts
@@ -0,0 +1,132 @@
+import { type ITransport } from 'wokwi-client-js';
+import { WebSocket } from 'ws';
+
+const retryDelays = [1000, 2000, 5000, 10000, 20000];
+
+enum ErrorStatus {
+  RequestTimeout = 408,
+  ServiceUnavailable = 503,
+  CfRequestTimeout = 524,
+}
+
+/**
+ * Transport for communicating with a Wokwi Simulator over a WebSocket.
+ * This can be used in Node.js to communicate with the Wokwi CLI.
+ */
+export class WebSocketTransport implements ITransport {
+  public onMessage: (message: any) => void = () => {};
+  public onClose?: (code: number, reason?: string) => void;
+  public onError?: (error: Error) => void;
+
+  private socket: WebSocket;
+  private connectionAttempts = 0;
+  
+  // to suppress close events when intentionally closing
+  private ignoreClose = false;  
+  
+  // retryable error statuses
+  private readonly errorStates = [ 
+    ErrorStatus.RequestTimeout,
+    ErrorStatus.ServiceUnavailable,
+    ErrorStatus.CfRequestTimeout,
+  ];
+
+  constructor(
+    private readonly token: string,
+    private readonly server: string,
+    private readonly version: string,
+    private readonly sha: string
+  ) {
+    this.socket = this.createSocket();
+  }
+
+  private createSocket(): WebSocket {
+    return new WebSocket(this.server, {
+      headers: {
+        Authorization: `Bearer ${this.token}`,
+        'User-Agent': `wokwi-cli/${this.version} (${this.sha})`,
+      },
+    });
+  }
+
+  async connect(): Promise<void> {
+    await new Promise<void>((resolve, reject) => {
+      const handleOpen = () => {
+        this.socket.on('message', (data) => {
+          let dataStr: string;
+          if (typeof data === 'string') {
+            dataStr = data;
+          } else if (Buffer.isBuffer(data)) {
+            dataStr = data.toString('utf-8');
+          } else {
+            dataStr = Buffer.from(data as ArrayBuffer).toString('utf-8');
+          }
+          const messageObj = JSON.parse(dataStr);
+          this.onMessage(messageObj);
+        });
+        this.socket.on('close', (code, reason) => {
+          if (!this.ignoreClose) {
+            this.onClose?.(code, reason?.toString());
+          }
+          this.ignoreClose = false;
+        });
+        resolve();
+      };
+
+      const handleError = (err: Error) => {
+        cleanup();
+        reject(new Error(`Error connecting to ${this.server}: ${err.message}`));
+      };
+
+      const handleUnexpected = (_req: any, res: any) => {
+        cleanup();
+        const statusCode = res.statusCode;
+        const statusMsg = res.statusMessage ?? '';
+        // Decide whether to retry based on the status code
+        if (this.errorStates.includes(statusCode)) {
+          const delay = retryDelays[this.connectionAttempts++];
+          if (delay != null) {
+            console.warn(`Connection to ${this.server} failed: ${statusMsg} (${statusCode}).`);
+            console.log(`Will retry in ${delay}ms...`);
+            this.ignoreClose = true;
+            this.socket.close();
+            setTimeout(() => {
+              console.log(`Retrying connection to ${this.server}...`);
+              this.socket = this.createSocket();
+              this.connect().then(resolve).catch(reject);
+            }, delay);
+            return;
+          }
+          reject(new Error(`Failed to connect to ${this.server}. Giving up.`));
+        } else {
+          reject(new Error(`Error connecting to ${this.server}: ${statusCode} ${statusMsg}`));
+        }
+      };
+
+      // remove handlers after success/failure to avoid leaks
+      const cleanup = () => {
+        this.socket.off('open', handleOpen);
+        this.socket.off('error', handleError);
+        this.socket.off('unexpected-response', handleUnexpected);
+      };
+
+      // attach handlers for this connection attempt
+      this.socket.on('open', handleOpen);
+      this.socket.on('error', handleError);
+      this.socket.on('unexpected-response', handleUnexpected);
+    });
+  }
+
+  send(message: any): void {
+    this.socket.send(JSON.stringify(message));
+  }
+
+  close(): void {
+    this.ignoreClose = true;
+    if (this.socket.readyState === WebSocket.OPEN) {
+      this.socket.close();
+    } else {
+      this.socket.terminate();
+    }
+  }
+}
diff --git a/packages/wokwi-cli/src/uploadFirmware.ts b/packages/wokwi-cli/src/uploadFirmware.ts
index f478b90..ceeca82 100644
--- a/packages/wokwi-cli/src/uploadFirmware.ts
+++ b/packages/wokwi-cli/src/uploadFirmware.ts
@@ -1,11 +1,11 @@
 import { readFileSync } from 'fs';
 import { basename, dirname, resolve } from 'path';
-import { type APIClient } from './APIClient.js';
+import { type APIClient } from 'wokwi-client-js';
 import { type IESP32FlasherJSON } from './esp/flasherArgs.js';
 
 interface IFirmwarePiece {
   offset: number;
-  data: ArrayBuffer;
+  data: Uint8Array;
 }
 
 const MAX_FIRMWARE_SIZE = 4 * 1024 * 1024;
@@ -24,7 +24,7 @@ export async function uploadESP32Firmware(client: APIClient, firmwarePath: strin
       throw new Error(`Invalid offset in flasher_args.json flash_files: ${offset}`);
     }
 
-    const data = readFileSync(resolve(dirname(firmwarePath), file));
+    const data = new Uint8Array(readFileSync(resolve(dirname(firmwarePath), file)));
     firmwareParts.push({ offset: offsetNum, data });
     firmwareSize = Math.max(firmwareSize, offsetNum + data.byteLength);
   }
@@ -37,7 +37,7 @@ export async function uploadESP32Firmware(client: APIClient, firmwarePath: strin
 
   const firmwareData = new Uint8Array(firmwareSize);
   for (const { offset, data } of firmwareParts) {
-    firmwareData.set(new Uint8Array(data), offset);
+    firmwareData.set(data, offset);
   }
   await client.fileUpload('firmware.bin', firmwareData);
 
@@ -51,6 +51,6 @@ export async function uploadFirmware(client: APIClient, firmwarePath: string) {
 
   const extension = firmwarePath.split('.').pop();
   const firmwareName = `firmware.${extension}`;
-  await client.fileUpload(firmwareName, readFileSync(firmwarePath));
+  await client.fileUpload(firmwareName, new Uint8Array(readFileSync(firmwarePath)));
   return firmwareName;
 }
diff --git a/packages/wokwi-cli/tools/build.js b/packages/wokwi-cli/tools/bundle.js
similarity index 50%
rename from packages/wokwi-cli/tools/build.js
rename to packages/wokwi-cli/tools/bundle.js
index 53aa66e..365bc8a 100644
--- a/packages/wokwi-cli/tools/build.js
+++ b/packages/wokwi-cli/tools/bundle.js
@@ -1,18 +1,26 @@
 import { execSync } from 'child_process';
 import { build } from 'esbuild';
 import { mkdirSync, readFileSync, writeFileSync } from 'fs';
+import { fileURLToPath } from 'url';
+import { dirname, join } from 'path';
 
-const { version } = JSON.parse(readFileSync('package.json', 'utf8'));
-const sha = execSync('git rev-parse --short=12 HEAD').toString().trim();
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+const rootDir = join(__dirname, '..');
 
+// Get version and SHA
+const { version } = JSON.parse(readFileSync(join(rootDir, 'package.json'), 'utf8'));
+const sha = execSync('git rev-parse --short=12 HEAD', { cwd: rootDir }).toString().trim();
+
+// Generate version.json for distribution
 const installCommands = {
   win32: 'iwr https://wokwi.com/ci/install.ps1 -useb | iex',
   default: 'curl -L https://wokwi.com/ci/install.sh | sh',
 };
 
-mkdirSync('dist/bin', { recursive: true });
+mkdirSync(join(rootDir, 'dist/bin'), { recursive: true });
 writeFileSync(
-  'dist/bin/version.json',
+  join(rootDir, 'dist/bin/version.json'),
   JSON.stringify(
     {
       version,
@@ -24,10 +32,11 @@ writeFileSync(
   ),
 );
 
+// Bundle the CLI
 const options = {
   platform: 'node',
-  entryPoints: ['./src/main.ts'],
-  outfile: './dist/cli.cjs',
+  entryPoints: [join(rootDir, 'src/main.ts')],
+  outfile: join(rootDir, 'dist/cli.cjs'),
   bundle: true,
   define: {
     'process.env.WOKWI_CONST_CLI_VERSION': JSON.stringify(version),
@@ -36,3 +45,4 @@ const options = {
 };
 
 build(options).catch(() => process.exit(1));
+
diff --git a/packages/wokwi-cli/tsconfig.json b/packages/wokwi-cli/tsconfig.json
index 17efde7..f45021b 100644
--- a/packages/wokwi-cli/tsconfig.json
+++ b/packages/wokwi-cli/tsconfig.json
@@ -5,5 +5,5 @@
         "rootDir": "src"
     },
     "include": ["src/**/*.ts"],
-    "exclude": ["src/**/*.spec.ts"]
+    "exclude": ["src/**/*.spec.ts", "node_modules", "dist"]
 }
diff --git a/packages/wokwi-client-js/package.json b/packages/wokwi-client-js/package.json
new file mode 100644
index 0000000..f669dc8
--- /dev/null
+++ b/packages/wokwi-client-js/package.json
@@ -0,0 +1,61 @@
+{
+  "name": "wokwi-client-js",
+  "version": "0.18.3",
+  "description": "Wokwi Client JS Library",
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "type": "module",
+  "exports": {
+    ".": {
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.js"
+    },
+    "./browser": {
+      "types": "./dist/index.d.ts",
+      "import": "./dist/wokwi-client-js.browser.js"
+    },
+    "./transport/MessagePortTransport.js": {
+      "types": "./dist/transport/MessagePortTransport.d.ts",
+      "import": "./dist/transport/MessagePortTransport.js"
+    },
+    "./APIClient.js": {
+      "types": "./dist/APIClient.d.ts",
+      "import": "./dist/APIClient.js"
+    }
+  },
+  "files": [
+    "dist"
+  ],
+  "scripts": {
+    "prebuild": "pnpm run clean",
+    "build": "tsc && pnpm run build:browser",
+    "build:browser": "node tools/bundle-browser.js",
+    "clean": "rimraf dist",
+    "lint": "eslint src/**/*.ts",
+    "lint:fix": "eslint src/**/*.ts --fix"
+  },
+  "keywords": [
+    "wokwi",
+    "simulator",
+    "api",
+    "client",
+    "websocket",
+    "iot",
+    "embedded"
+  ],
+  "author": "Uri Shaked",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/wokwi/wokwi-cli"
+  },
+  "dependencies": {
+    "ws": "^8.13.0"
+  },
+  "devDependencies": {
+    "@types/ws": "^8.18.1",
+    "esbuild": "^0.25.2",
+    "rimraf": "^5.0.0",
+    "typescript": "^5.2.2"
+  }
+}
diff --git a/packages/wokwi-cli/src/APIClient.ts b/packages/wokwi-client-js/src/APIClient.ts
similarity index 66%
rename from packages/wokwi-cli/src/APIClient.ts
rename to packages/wokwi-client-js/src/APIClient.ts
index c543440..2d3ecc7 100644
--- a/packages/wokwi-cli/src/APIClient.ts
+++ b/packages/wokwi-client-js/src/APIClient.ts
@@ -1,5 +1,3 @@
-import { Writable } from 'stream';
-import { WebSocket } from 'ws';
 import type {
   APICommand,
   APIError,
@@ -11,13 +9,10 @@ import type {
   PinReadResponse,
 } from './APITypes.js';
 import { PausePoint, type PausePointParams } from './PausePoint.js';
-import { readVersion } from './readVersion.js';
-
-const DEFAULT_SERVER = process.env.WOKWI_CLI_SERVER ?? 'wss://wokwi.com/api/ws/beta';
-const retryDelays = [1000, 2000, 5000, 10000, 20000];
+import { ITransport } from './transport/ITransport.js';
+import { base64ToByteArray, byteArrayToBase64 } from './base64.js';
 
 export class APIClient {
-  private socket: WebSocket;
   private connectionAttempts = 0;
   private lastId = 0;
   private lastPausePointId = 0;
@@ -31,108 +26,45 @@ export class APIClient {
     [(result: any) => void, (error: Error) => void]
   >();
 
-  readonly connected;
+  readonly connected: Promise<void>;
 
   onConnected?: (helloMessage: APIHello) => void;
   onError?: (error: APIError) => void;
+  onEvent?: (event: APIEvent) => void;
 
   constructor(
-    readonly token: string,
-    readonly server = DEFAULT_SERVER,
+    private readonly transport: ITransport,
   ) {
-    this.socket = this.createSocket(token, server);
-    this.connected = this.connectSocket(this.socket);
-  }
-
-  private createSocket(token: string, server: string) {
-    const { sha, version } = readVersion();
-    return new WebSocket(server, {
-      headers: {
-        Authorization: `Bearer ${token}`,
-        'User-Agent': `wokwi-cli/${version} (${sha})`,
-      },
-    });
-  }
-
-  private async connectSocket(socket: WebSocket) {
-    await new Promise((resolve, reject) => {
-      socket.addEventListener('message', ({ data }) => {
-        if (typeof data === 'string') {
-          const message = JSON.parse(data);
-          this.processMessage(message);
-        } else {
-          console.error('Unsupported binary message');
-        }
-      });
-      this.socket.addEventListener('open', resolve);
-      this.socket.on('unexpected-response', (req, res) => {
-        this.closed = true;
-        this.socket.close();
-        const RequestTimeout = 408;
-        const ServiceUnavailable = 503;
-        const CfRequestTimeout = 524;
-        if (
-          res.statusCode === ServiceUnavailable ||
-          res.statusCode === RequestTimeout ||
-          res.statusCode === CfRequestTimeout
-        ) {
-          console.warn(
-            `Connection to ${this.server} failed: ${res.statusMessage ?? ''} (${res.statusCode}).`,
-          );
-          resolve(this.retryConnection());
-        } else {
-          reject(
-            new Error(
-              `Error connecting to ${this.server}: ${res.statusCode} ${res.statusMessage ?? ''}`,
-            ),
-          );
-        }
-      });
-      this.socket.addEventListener('error', (event) => {
-        reject(new Error(`Error connecting to ${this.server}: ${event.message}`));
-      });
-      this.socket.addEventListener('close', (event) => {
-        if (this.closed) {
-          return;
-        }
-
-        const message = `Connection to ${this.server} closed unexpectedly: code ${event.code}`;
-        if (this.onError) {
-          this.onError({ type: 'error', message });
-        } else {
-          console.error(message);
-        }
-      });
-    });
-  }
-
-  private async retryConnection() {
-    const delay = retryDelays[this.connectionAttempts++];
-    if (delay == null) {
-      throw new Error(`Failed to connect to ${this.server}. Giving up.`);
-    }
-
-    console.log(`Will retry in ${delay}ms...`);
+    this.transport.onMessage = (message) => { this.processMessage(message); };
+    this.transport.onClose = (code, reason) => { this.handleTransportClose(code, reason); };
+    this.transport.onError = (error) => { this.handleTransportError(error); };
 
-    await new Promise((resolve) => setTimeout(resolve, delay));
-
-    console.log(`Retrying connection to ${this.server}...`);
-    this.socket = this.createSocket(this.token, this.server);
-    this.closed = false;
-    await this.connectSocket(this.socket);
+    // Initiate connection
+    this.connected = this.transport.connect();
   }
 
-  async fileUpload(name: string, content: string | ArrayBuffer) {
+  async fileUpload(name: string, content: string | Uint8Array) {
     if (typeof content === 'string') {
       return await this.sendCommand('file:upload', { name, text: content });
     } else {
       return await this.sendCommand('file:upload', {
         name,
-        binary: Buffer.from(content).toString('base64'),
+        binary: byteArrayToBase64(content),
       });
     }
   }
 
+  async fileDownload(name: string): Promise<string | Uint8Array> {
+    const result = await this.sendCommand<{ text?: string; binary?: string }>('file:download', { name });
+    if (typeof result.text === 'string') {
+      return result.text;
+    } else if (typeof result.binary === 'string') {
+      return base64ToByteArray(result.binary);
+    } else {
+      throw new Error('Invalid file download response');
+    }
+  }
+
   async simStart(params: APISimStartParams) {
     this._running = false;
     return await this.sendCommand('sim:start', params);
@@ -174,9 +106,12 @@ export class APIClient {
     });
   }
 
-  serialMonitorWritable() {
+  async serialMonitorWritable() {
+    // Dynamic import for Node.js-only API
+    const { Writable } = await import('stream');
+    const { Buffer } = await import('buffer');
     return new Writable({
-      write: (chunk, encoding, callback) => {
+      write: (chunk: any, encoding: BufferEncoding, callback: (error?: Error | null) => void) => {
         if (typeof chunk === 'string') {
           chunk = Buffer.from(chunk, encoding);
         }
@@ -258,7 +193,7 @@ export class APIClient {
         params,
         id: id.toString(),
       };
-      this.socket.send(JSON.stringify(message));
+      this.transport.send(message);
     });
   }
 
@@ -278,8 +213,11 @@ export class APIClient {
         }
         console.error('API Error:', message.message);
         if (this.pendingCommands.size > 0) {
-          const [, reject] = this.pendingCommands.values().next().value;
-          reject(new Error(message.message));
+          const entry = this.pendingCommands.values().next().value;
+          if (entry) {
+            const [, reject] = entry;
+            reject(new Error(message.message));
+          }
         }
         break;
 
@@ -311,6 +249,7 @@ export class APIClient {
       }
     }
     this._lastNanos = message.nanos;
+    this.onEvent?.(message);
     this.apiEvents.dispatchEvent(new CustomEvent<APIEvent>(message.event, { detail: message }));
   }
 
@@ -346,8 +285,21 @@ export class APIClient {
 
   close() {
     this.closed = true;
-    if (this.socket.readyState === WebSocket.OPEN) {
-      this.socket.close();
-    }
+    this.transport.close();
+  }
+
+  private handleTransportClose(code: number, reason?: string) {
+    if (this.closed) return;
+    const target = (this as any).server ?? 'transport';
+    const msg = `Connection to ${target} closed unexpectedly: code ${code}${reason ? ` (${reason})` : ''}`;
+    const errorObj: APIError = { type: 'error', message: msg };
+    this.onError?.(errorObj);
+    console.error(msg);
+  }
+
+  private handleTransportError(error: Error) {
+    const errorObj: APIError = { type: 'error', message: error.message };
+    this.onError?.(errorObj);
+    console.error('Transport error:', error.message);
   }
 }
diff --git a/packages/wokwi-cli/src/APITypes.ts b/packages/wokwi-client-js/src/APITypes.ts
similarity index 98%
rename from packages/wokwi-cli/src/APITypes.ts
rename to packages/wokwi-client-js/src/APITypes.ts
index 23b5f3f..4e63fbb 100644
--- a/packages/wokwi-cli/src/APITypes.ts
+++ b/packages/wokwi-client-js/src/APITypes.ts
@@ -57,4 +57,5 @@ export interface APISimStartParams {
 export interface PinReadResponse {
   pin: string;
   value: number;
+  voltage: number;
 }
diff --git a/packages/wokwi-cli/src/PausePoint.ts b/packages/wokwi-client-js/src/PausePoint.ts
similarity index 99%
rename from packages/wokwi-cli/src/PausePoint.ts
rename to packages/wokwi-client-js/src/PausePoint.ts
index 983bde1..a494804 100644
--- a/packages/wokwi-cli/src/PausePoint.ts
+++ b/packages/wokwi-client-js/src/PausePoint.ts
@@ -29,3 +29,4 @@ export class PausePoint<T = any> {
     this._resolve(info);
   }
 }
+
diff --git a/packages/wokwi-client-js/src/base64.ts b/packages/wokwi-client-js/src/base64.ts
new file mode 100644
index 0000000..a05cf5c
--- /dev/null
+++ b/packages/wokwi-client-js/src/base64.ts
@@ -0,0 +1,41 @@
+const b64dict = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
+
+export function base64ToByteArray(base64str: string): Uint8Array {
+  if (typeof Buffer !== 'undefined') {
+    // Node.js
+    return Uint8Array.from(Buffer.from(base64str, 'base64'));
+  } else {
+    // Browser
+    const binaryString = globalThis.atob(base64str);
+    return Uint8Array.from(binaryString, (c) => c.charCodeAt(0));
+  }
+}
+
+
+export function byteArrayToBase64(bytes: Uint8Array): string {  
+  if (typeof Buffer !== 'undefined') {
+    // Node.js
+    return Buffer.from(bytes.buffer, bytes.byteOffset, bytes.byteLength).toString('base64');
+  } else {
+    // Browser: manual base64 encoding
+    let result = '';
+    for (let i = 0; i < bytes.length - 2; i += 3) {
+      result += b64dict[bytes[i] >> 2];
+      result += b64dict[((bytes[i] & 0x03) << 4) | (bytes[i + 1] >> 4)];
+      result += b64dict[((bytes[i + 1] & 0x0f) << 2) | (bytes[i + 2] >> 6)];
+      result += b64dict[bytes[i + 2] & 0x3f];
+    }
+    if (bytes.length % 3 === 1) {
+      result += b64dict[bytes[bytes.length - 1] >> 2];
+      result += b64dict[(bytes[bytes.length - 1] & 0x03) << 4];
+      result += '==';
+    }
+    if (bytes.length % 3 === 2) {
+      result += b64dict[bytes[bytes.length - 2] >> 2];
+      result += b64dict[((bytes[bytes.length - 2] & 0x03) << 4) | (bytes[bytes.length - 1] >> 4)];
+      result += b64dict[(bytes[bytes.length - 1] & 0x0f) << 2];
+      result += '=';
+    }
+    return result;
+  }
+}
diff --git a/packages/wokwi-client-js/src/index.ts b/packages/wokwi-client-js/src/index.ts
new file mode 100644
index 0000000..9761c11
--- /dev/null
+++ b/packages/wokwi-client-js/src/index.ts
@@ -0,0 +1,32 @@
+// Main API Client
+export { APIClient } from './APIClient.js';
+
+// Transport interfaces and implementations
+export { ITransport } from './transport/ITransport.js';
+export { MessagePortTransport } from './transport/MessagePortTransport.js';
+
+// Pause Point
+export { PausePoint } from './PausePoint.js';
+export type {
+  PausePointType,
+  PausePointParams,
+  ITimePausePoint,
+  ISerialBytesPausePoint,
+} from './PausePoint.js';
+
+// API Types
+export type {
+  APIError,
+  APIHello,
+  APICommand,
+  APIResponse,
+  APIEvent,
+  APIResultError,
+  APISimStartParams,
+  SerialMonitorDataPayload,
+  ChipsLogPayload,
+  PinReadResponse,
+} from './APITypes.js';
+
+// Utilities
+export { base64ToByteArray, byteArrayToBase64 } from './base64.js';
diff --git a/packages/wokwi-client-js/src/transport/ITransport.ts b/packages/wokwi-client-js/src/transport/ITransport.ts
new file mode 100644
index 0000000..4fde9fd
--- /dev/null
+++ b/packages/wokwi-client-js/src/transport/ITransport.ts
@@ -0,0 +1,15 @@
+export interface ITransport {
+  /** Callback to handle incoming messages (parsed as objects) */
+  onMessage: (message: any) => void;
+  /** Optional callback for transport closure events */
+  onClose?: (code: number, reason?: string) => void;
+  /** Optional callback for transport-level errors */
+  onError?: (error: Error) => void;
+
+  /** Send a message through the transport */
+  send(message: any): void;
+  /** Establish the connection (if needed) */
+  connect(): Promise<void>;
+  /** Close the transport */
+  close(): void;
+}
diff --git a/packages/wokwi-client-js/src/transport/MessagePortTransport.ts b/packages/wokwi-client-js/src/transport/MessagePortTransport.ts
new file mode 100644
index 0000000..3b5104d
--- /dev/null
+++ b/packages/wokwi-client-js/src/transport/MessagePortTransport.ts
@@ -0,0 +1,37 @@
+import { ITransport } from "./ITransport.js";
+
+/**
+ * Transport for communicating with a Wokwi Simulator over a MessagePort.
+ * This can be used in the browser to communicate with the Wokwi Simulator in iframe mode.
+ */
+export class MessagePortTransport implements ITransport {
+  public onMessage: (message: any) => void = () => {};
+  public onClose?: (code: number, reason?: string) => void;
+  public onError?: (error: Error) => void;
+
+  private readonly port: MessagePort;
+
+  constructor(port: MessagePort) {
+    this.port = port;
+    this.port.onmessage = (event) => {
+      this.onMessage(event.data);
+    };
+    this.port.start();
+  }
+
+  async connect(): Promise<void> {
+    // MessagePort is ready to use immediately; no handshake needed
+  }
+
+  send(message: any): void {
+    this.port.postMessage(message);
+  }
+
+  close(): void {
+    try {
+      this.port.close();
+    } catch {
+      // Ignore errors when closing port
+    }
+  }
+}
diff --git a/packages/wokwi-client-js/tools/bundle-browser.js b/packages/wokwi-client-js/tools/bundle-browser.js
new file mode 100644
index 0000000..da5b731
--- /dev/null
+++ b/packages/wokwi-client-js/tools/bundle-browser.js
@@ -0,0 +1,35 @@
+import { build } from 'esbuild';
+import { fileURLToPath } from 'url';
+import { dirname, join } from 'path';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+const rootDir = join(__dirname, '..');
+
+const options = {
+  entryPoints: [join(rootDir, 'src/index.ts')],
+  outfile: join(rootDir, 'dist/wokwi-client-js.browser.js'),
+  bundle: true,
+  platform: 'browser',
+  format: 'esm',
+  target: 'es2020',
+  // Explicitly mark Node.js-only packages as external
+  external: ['ws', 'stream', 'buffer'],
+  banner: {
+    js: `// Browser bundle of wokwi-client-js
+// Note: serialMonitorWritable() requires Node.js and won't work in browsers
+// Use MessagePortTransport for browser communication with Wokwi Simulator
+`,
+  },
+};
+
+// Build the browser bundle
+build(options)
+  .then(() => {
+    console.log('✓ Browser bundle created: dist/wokwi-client-js.browser.js');
+  })
+  .catch((error) => {
+    console.error('✗ Browser bundle failed:', error);
+    process.exit(1);
+  });
+
diff --git a/packages/wokwi-client-js/tsconfig.json b/packages/wokwi-client-js/tsconfig.json
new file mode 100644
index 0000000..0e0f569
--- /dev/null
+++ b/packages/wokwi-client-js/tsconfig.json
@@ -0,0 +1,10 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "dist",
+    "rootDir": "src"
+  },
+  "include": ["src/**/*.ts"],
+  "exclude": ["src/**/*.spec.ts", "node_modules"]
+}
+
diff --git a/playwright.config.ts b/playwright.config.ts
new file mode 100644
index 0000000..112c638
--- /dev/null
+++ b/playwright.config.ts
@@ -0,0 +1,33 @@
+import { defineConfig, devices } from '@playwright/test';
+
+export default defineConfig({
+  testDir: './test',
+  fullyParallel: true,
+  forbidOnly: !!process.env.CI,
+  retries: process.env.CI ? 2 : 0,
+  workers: process.env.CI ? 1 : undefined,
+  reporter: 'html',
+  use: {
+    trace: 'on-first-retry',
+  },
+  projects: [
+    {
+      name: 'chromium',
+      use: { ...devices['Desktop Chrome'] },
+    },
+    {
+      name: 'firefox',
+      use: { ...devices['Desktop Firefox'] },
+    },
+    {
+      name: 'webkit',
+      use: { ...devices['Desktop Safari'] },
+    },
+  ],
+  webServer: {
+    command: 'npx --yes http-server . -p 8000 -c-1',
+    url: 'http://127.0.0.1:8000',
+    reuseExistingServer: !process.env.CI,
+    timeout: 120 * 1000,
+  },
+});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 7fd4032..7f1d95c 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -7,38 +7,13 @@ settings:
 importers:
 
   .:
-    dependencies:
-      '@clack/prompts':
-        specifier: ^0.7.0
-        version: 0.7.0
-      '@iarna/toml':
-        specifier: 2.2.5
-        version: 2.2.5
-      '@modelcontextprotocol/sdk':
-        specifier: ^1.0.0
-        version: 1.20.2
-      arg:
-        specifier: ^5.0.2
-        version: 5.0.2
-      chalk:
-        specifier: ^5.3.0
-        version: 5.6.2
-      chalk-template:
-        specifier: ^1.1.0
-        version: 1.1.2
-      pngjs:
-        specifier: ^7.0.0
-        version: 7.0.0
-      ws:
-        specifier: ^8.13.0
-        version: 8.18.3
-      yaml:
-        specifier: ^2.3.1
-        version: 2.8.1
     devDependencies:
       '@eslint/js':
         specifier: ^9.39.1
         version: 9.39.1
+      '@playwright/test':
+        specifier: ^1.48.0
+        version: 1.56.1
       esbuild:
         specifier: ^0.25.2
         version: 0.25.11
@@ -99,6 +74,9 @@ importers:
       pngjs:
         specifier: ^7.0.0
         version: 7.0.0
+      wokwi-client-js:
+        specifier: workspace:*
+        version: link:../wokwi-client-js
       ws:
         specifier: ^8.13.0
         version: 8.18.3
@@ -140,6 +118,25 @@ importers:
         specifier: ^3.0.5
         version: 3.2.4(@types/node@24.9.2)(jiti@2.6.1)(tsx@4.20.6)(yaml@2.8.1)
 
+  packages/wokwi-client-js:
+    dependencies:
+      ws:
+        specifier: ^8.13.0
+        version: 8.18.3
+    devDependencies:
+      '@types/ws':
+        specifier: ^8.18.1
+        version: 8.18.1
+      esbuild:
+        specifier: ^0.25.2
+        version: 0.25.11
+      rimraf:
+        specifier: ^5.0.0
+        version: 5.0.10
+      typescript:
+        specifier: ^5.2.2
+        version: 5.9.3
+
 packages:
 
   '@babel/generator@7.28.5':
@@ -421,6 +418,11 @@ packages:
     resolution: {integrity: sha512-+1VkjdD0QBLPodGrJUeqarH8VAIvQODIbwh9XpP5Syisf7YoQgsJKPNFoqqLQlu+VQ/tVSshMR6loPMn8U+dPg==}
     engines: {node: '>=14'}
 
+  '@playwright/test@1.56.1':
+    resolution: {integrity: sha512-vSMYtL/zOcFpvJCW71Q/OEGQb7KYBPAdKh35WNSkaZA75JlAO8ED8UN6GUNTm3drWomcbcqRPFqQbLae8yBTdg==}
+    engines: {node: '>=18'}
+    hasBin: true
+
   '@rollup/rollup-android-arm-eabi@4.52.5':
     resolution: {integrity: sha512-8c1vW4ocv3UOMp9K+gToY5zL2XiiVw3k7f1ksf4yO1FlDFQ1C2u72iACFnSOceJFsWskc2WZNqeRhFRPzv+wtQ==}
     cpu: [arm]
@@ -1070,6 +1072,11 @@ packages:
   fs-constants@1.0.0:
     resolution: {integrity: sha512-y6OAwoSIf7FyjMIv94u+b5rdheZEjzR63GTyZJm5qh4Bi+2YgwLCcI/fPFZkL5PSixOt6ZNKm+w+Hfp/Bciwow==}
 
+  fsevents@2.3.2:
+    resolution: {integrity: sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==}
+    engines: {node: ^8.16.0 || ^10.6.0 || >=11.0.0}
+    os: [darwin]
+
   fsevents@2.3.3:
     resolution: {integrity: sha512-5xoDfX+fL7faATnagmWPpbFtwh/R77WmMMqqHGS65C3vvB0YHrgF+B1YmZ3441tMj5n63k0212XNoJwzlhffQw==}
     engines: {node: ^8.16.0 || ^10.6.0 || >=11.0.0}
@@ -1503,6 +1510,16 @@ packages:
     resolution: {integrity: sha512-ueGLflrrnvwB3xuo/uGob5pd5FN7l0MsLf0Z87o/UQmRtwjvfylfc9MurIxRAWywCYTgrvpXBcqjV4OfCYGCIQ==}
     engines: {node: '>=16.20.0'}
 
+  playwright-core@1.56.1:
+    resolution: {integrity: sha512-hutraynyn31F+Bifme+Ps9Vq59hKuUCz7H1kDOcBs+2oGguKkWTU50bBWrtz34OUWmIwpBTWDxaRPXrIXkgvmQ==}
+    engines: {node: '>=18'}
+    hasBin: true
+
+  playwright@1.56.1:
+    resolution: {integrity: sha512-aFi5B0WovBHTEvpM3DzXTUaeN6eN0qWnTkKx4NQaH4Wvcmc153PdaY2UBdSYKaGYw+UyWXSVyxDUg5DoPEttjw==}
+    engines: {node: '>=18'}
+    hasBin: true
+
   pngjs@7.0.0:
     resolution: {integrity: sha512-LKWqWJRhstyYo9pGvgor/ivk2w94eSjE3RGVuzLGlr3NmD8bf7RcYGze1mNdEHRP6TRP6rMuDHk5t44hnTRyow==}
     engines: {node: '>=14.19.0'}
@@ -2225,6 +2242,10 @@ snapshots:
   '@pkgjs/parseargs@0.11.0':
     optional: true
 
+  '@playwright/test@1.56.1':
+    dependencies:
+      playwright: 1.56.1
+
   '@rollup/rollup-android-arm-eabi@4.52.5':
     optional: true
 
@@ -2950,6 +2971,9 @@ snapshots:
 
   fs-constants@1.0.0: {}
 
+  fsevents@2.3.2:
+    optional: true
+
   fsevents@2.3.3:
     optional: true
 
@@ -3318,6 +3342,14 @@ snapshots:
 
   pkce-challenge@5.0.0: {}
 
+  playwright-core@1.56.1: {}
+
+  playwright@1.56.1:
+    dependencies:
+      playwright-core: 1.56.1
+    optionalDependencies:
+      fsevents: 2.3.2
+
   pngjs@7.0.0: {}
 
   postcss@8.5.6:
diff --git a/scripts/test-cli-integration.sh b/scripts/test-cli-integration.sh
new file mode 100755
index 0000000..86df7dc
--- /dev/null
+++ b/scripts/test-cli-integration.sh
@@ -0,0 +1,52 @@
+#!/bin/bash
+set -e
+
+TEST_PROJECT_DIR="test-project"
+TEST_REPO="https://github.com/wokwi/esp-idf-hello-world.git"
+
+# Clone test project if it doesn't exist
+if [ ! -d "$TEST_PROJECT_DIR" ]; then
+  echo "Cloning test project..."
+  git clone "$TEST_REPO" "$TEST_PROJECT_DIR"
+else
+  echo "Test project already exists, skipping clone..."
+fi
+
+# Create test scenario file
+cat > "$TEST_PROJECT_DIR/test-scenario.yaml" << 'EOF'
+name: "Basic Hello World Test"
+version: 1
+description: "Test that the ESP32 hello world program outputs expected text"
+
+steps:
+  - name: "Wait for boot and hello message"
+    wait-serial: "Hello world!"
+
+  - name: "Wait for chip information"
+    wait-serial: "This is esp32 chip"
+
+  - name: "Wait for restart message"
+    wait-serial: "Restarting in 10 seconds"
+EOF
+
+echo "Test scenario file created."
+
+# Check if WOKWI_CLI_TOKEN is set
+if [ -z "$WOKWI_CLI_TOKEN" ]; then
+  echo "Warning: WOKWI_CLI_TOKEN environment variable is not set."
+  echo "Integration tests require a Wokwi API token to run."
+  echo "Set WOKWI_CLI_TOKEN environment variable to run these tests."
+  exit 1
+fi
+
+# Run CLI tests
+echo "Running CLI integration tests..."
+
+echo "Test 1: Basic expect-text test"
+pnpm cli "$TEST_PROJECT_DIR" --timeout 5000 --expect-text "Hello"
+
+echo "Test 2: Scenario file test"
+pnpm cli "$TEST_PROJECT_DIR" --scenario "test-scenario.yaml" --timeout 15000
+
+echo "All CLI integration tests passed!"
+
diff --git a/test/wokwi-embed/index.html b/test/wokwi-embed/index.html
new file mode 100644
index 0000000..053d1c4
--- /dev/null
+++ b/test/wokwi-embed/index.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>MicroPython + ESP32 on Wokwi</title>
+    <script type="importmap">
+      {
+        "imports": {
+          "wokwi-client-js": "/packages/wokwi-client-js/dist/index.js"
+        }
+      }
+    </script>
+  </head>
+  <body>
+    <h1>MicroPython + ESP32 on Wokwi</h1>
+    <div>
+      <button class="start-button">Start</button>
+    </div>
+    <iframe
+      src="https://wokwi.com/experimental/embed?client_id=wokwi_client_omf4ejkz6n6twj7d3x2eqmyp"
+      width="50%"
+      height="500"
+      id="wokwi-embed"
+    ></iframe>
+    <h2>Serial Monitor Output</h2>
+    <div id="output"><pre id="output-text"></pre></div>
+    <script type="module" src="script.js"></script>
+  </body>
+</html>
\ No newline at end of file
diff --git a/test/wokwi-embed/script.js b/test/wokwi-embed/script.js
new file mode 100644
index 0000000..25716f3
--- /dev/null
+++ b/test/wokwi-embed/script.js
@@ -0,0 +1,66 @@
+import { MessagePortTransport, APIClient } from 'wokwi-client-js';
+
+const diagram = `{
+  "version": 1,
+  "author": "Uri Shaked",
+  "editor": "wokwi",
+  "parts": [
+    {
+      "type": "board-esp32-devkit-c-v4",
+      "id": "esp",
+      "top": 0,
+      "left": 0,
+      "attrs": { "env": "micropython-20231227-v1.22.0" }
+    }
+  ],
+  "connections": [ [ "esp:TX", "$serialMonitor:RX", "", [] ], [ "esp:RX", "$serialMonitor:TX", "", [] ] ],
+  "dependencies": {}
+}`;
+
+const microPythonCode = `
+import time
+while True:
+    print(f"Hello, World {time.time()}")
+    time.sleep(1)
+`;
+
+const outputText = document.getElementById('output-text');
+
+window.addEventListener('message', async (event) => {
+  if (!event.data.port) {
+    return;
+  }
+
+  const client = new APIClient(new MessagePortTransport(event.data.port));
+
+  // Wait for connection
+  await client.connected;
+  console.log('Wokwi client connected');
+
+  // Set up event listeners
+  client.listen('serial-monitor:data', (event) => {
+    const rawBytes = new Uint8Array(event.payload.bytes);
+    outputText.textContent += new TextDecoder().decode(rawBytes);
+  });
+
+  // Initialize simulation
+  try {
+    await client.serialMonitorListen();
+    await client.fileUpload('main.py', microPythonCode);
+    await client.fileUpload('diagram.json', diagram);
+  } catch (error) {
+    console.error('Error initializing simulation:', error);
+  }
+
+  document.querySelector('.start-button').addEventListener('click', async () => {
+    try {
+      await client.simStart({
+        firmware: 'main.py',
+        elf: 'main.py',
+      });
+    } catch (error) {
+      console.error('Error starting simulation:', error);
+    }
+  });
+});
+console.log('Wokwi ESP32 MicroPython script loaded');
\ No newline at end of file
diff --git a/test/wokwi-embed/wokwi-embed.spec.ts b/test/wokwi-embed/wokwi-embed.spec.ts
new file mode 100644
index 0000000..4230c37
--- /dev/null
+++ b/test/wokwi-embed/wokwi-embed.spec.ts
@@ -0,0 +1,21 @@
+import { test, expect, type Page } from '@playwright/test';
+
+test.describe('Wokwi Embed', () => {
+  test('should start simulation and wait for output', async ({ page }: { page: Page }) => {
+    await page.goto('http://127.0.0.1:8000/test/wokwi-embed/');
+
+    // Wait 3 seconds after page load
+    await page.waitForTimeout(3000);
+
+    // Click the start button
+    const startButton = page.locator('.start-button');
+    await startButton.click();
+
+    // Wait until output-text contains the expected messages
+    const outputText = page.locator('#output-text');
+    await expect(outputText).toContainText('Hello, World 2', { timeout: 60000 });
+    await expect(outputText).toContainText('Hello, World 3', { timeout: 60000 });
+    await expect(outputText).toContainText('Hello, World 4', { timeout: 60000 });
+  });
+});
+
diff --git a/tsconfig.json b/tsconfig.json
index be80751..2fc49ab 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -2,6 +2,8 @@
     "extends": "./tsconfig.base.json",
     "include": [
         "eslint.config.ts",
+        "playwright.config.ts",
+        "vitest.config.ts",
         "./test/**/*.test.ts",
         "./test/**/*.ts",
         "./packages/*/src/**/*.ts"
diff --git a/vitest.config.ts b/vitest.config.ts
new file mode 100644
index 0000000..cdc0391
--- /dev/null
+++ b/vitest.config.ts
@@ -0,0 +1,15 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    exclude: [
+      '**/node_modules/**',
+      '**/dist/**',
+      '**/build/**',
+      '**/playwright-report/**',
+      '**/test-results/**',
+      '**/test/wokwi-embed/**', // Exclude Playwright tests
+    ],
+  },
+});
+