v0.1.0 - Initial Release

mcp-apps-testing v0.1.0 - Initial Release

The first UI testing framework built specifically for Model Context Protocol applications.

Test your MCP apps exactly how users experience them - with real browser rendering, simulated IDE environments, and complete JSON-RPC message control.

Highlights

• MockMCPHost - Simulates IDE hosting environments (Claude, VS Code) with auto-response to common protocol messages
• TransportInterceptor - Mock, record, and assert on every JSON-RPC request and response
• Host Profiles - Pre-configured environments (Claude, VSCode, Generic) with distinct capabilities and themes
• Fluent API - Human-readable test code with createMCPTestContext() for quick setup
• UI + Protocol Testing - Validate both visual rendering and protocol interactions in a single framework

Installation

npm install mcp-apps-testing @playwright/test --save-dev
npx playwright install chromium

Quick Example

import { test, expect } from '@playwright/test';
import { MockMCPHost } from 'mcp-apps-testing';

test('MCP app responds to tool calls', async () => {
  const host = new MockMCPHost({ hostProfile: 'Claude' });

  host.getInterceptor().mockResponse('tools/call', (req) => ({
    jsonrpc: '2.0',
    id: req.id,
    result: { content: [{ type: 'text', text: 'Hello, World!' }] }
  }));

  const response = await host.callTool('greet', { name: 'World' });
  expect(response.result.content[0].text).toBe('Hello, World!');

  await host.cleanup();
});

Exported API

Export	Type	Description
MockMCPHost	Class	Simulates an MCP host environment
TransportInterceptor	Class	Intercepts and mocks JSON-RPC messages
HostProfiles	Object	Pre-built host profile configurations
ClaudeProfile / VSCodeProfile / GenericProfile	Object	Individual host profiles
applyTheme	Function	Applies a host profile's theme
createMCPTestContext	Function	Factory for quick test setup

Requirements

• Node.js >= 18.0.0
• @playwright/test ^1.40.0 (peer dependency)

Links

• Documentation
• Report Issues
• MIT License

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Note: This is a pre-1.0 release (0.1.0). The API may evolve based on community feedback. Please report any issues or feature requests!