MCP Test Servers

A collection of test servers implementing the Model Context Protocol (MCP).

🚀 Quick Install Gallery

Visit our GitHub Pages Gallery for one-click install buttons that work directly with Cursor!

Manual Installation

npx -y @msfeldstein/mcp-test-servers <server>

Development

Use the cli.js directly for development

{
  "mcpServers": {
    "test-server": {
      "command": "/Users/feldstein/Source/mcp-test-servers/src/cli.js",
      "args": [
        "ping"
      ],
      "env": {}
    }
  }
}

Available Servers

- all-types: Demonstrates various tool parameter types supported by MCP
- bad-param: Server with an intentionally malformed parameter name
- big-response: Server that returns large responses
- broken-tool: Server with intentionally broken tool
- broken-schema: Server with invalid JSON schema using oneOf/allOf/anyOf at top level
- broken-schema-fastmcp: FastMCP server with genuinely broken schemas using oneOf/allOf/anyOf at top level
- crash-on-startup: Server that crashes on startup
- combined: Server with tools and resources
- duplicate-names: Server with duplicate names for resources
- elicitation: Server demonstrating MCP elicitation feature - requests user information (name, age, contact details, preferences) through structured forms
- enum-param: Tool has enum string parameter
- integer-anyof-bug: Reproduces Cursor's integer validation bug with anyOf schema - parameters with {"anyOf": [{"type": "integer"}, {"type": "null"}]} fail validation with 'got number' error
- env-check: Checks for SHOULD_RUN environment variable being passed properly
- env-echo: Echoes the environment variables
- gpt5-breaker: Server with SQL query execution tool using complex parameter validation
- graphing: MCP Apps server with show-graphing-ui; UI renders an inline chart with Chart.js
- headers: FastMCP server that safely returns HTTP header information
- instructions: Server with instructions and a makeRequest tool that returns success for value 42
- image: Tool returns an image of sonic the hedgehog
- long-description: Publicize a very long description configured via env var
- long-running: Server that sends progress notifications every 2 seconds for a 20-second task
- many-resources: Server with multiple resources
- many-tools: Server with 100 tools that each return 'ack'
- math: Server with basic math function tools (add, subtract, multiply, divide, power, sqrt, factorial)
- missing-type: Server with tools missing the required 'type' field in parameter schemas
- missing-type-fastmcp: FastMCP server with genuinely missing 'type' fields in tool schemas
- named: Server with configurable name via MCP_SERVER_NAME environment variable
- notion-gemini-repro: Server with complex nested schema that breaks on some models (Notion API reproduction case) - inline schema
- notion-gemini-repro-raw: Server with complex nested schema that breaks on some models (Notion API reproduction case) - exact raw schema object
- number-param: Tool with a number parameter
- oauth-repro: Reproduces OAuth 2.0 flow issues with proper discovery endpoints - runs resource server on port 3001 and auth server on port 3002
- oauth-debug: OAuth debugging server with comprehensive logging and endpoint tracking - runs resource server on port 3003 and auth server on port 3004
- oauth-callback-test: OAuth callback testing server that simulates Cursor 1.4.x endpoint discovery bugs - runs on port 3005
- oauth-edge-case: OAuth server with configurable edge cases to trigger discovery bugs - resource server on port 3006, auth server on port 3007
- oauth-bug-trigger: Specialized server designed to reproduce the exact Cursor 1.4.x OAuth discovery bug - resource server on port 3008, auth server on port 3009
- optional-param: Tool has an optional param
- pattern-param: Tool has a parameter with a pattern match
- ping: A simple server that responds with 'pong'
- prompts: Server with two prompts - one static greeting and one dynamic story generator with character name and location parameters
- raw-broken: Raw JSON-RPC MCP server with genuinely broken schemas (no framework validation)
- resource: Resource server implementation
- resource-lister: Server that publishes 5 resources and has a tool to list them
- roots-echo: Server that demonstrates MCP roots functionality by echoing back the roots provided by the client
- session-inactivity: Streamable HTTP server that expires sessions after 30 seconds of inactivity to test session management
- session-management: HTTP server that implements MCP session management behavior - assigns session IDs, requires them in requests, returns 404 for terminated sessions
- sse-timeout: Streamable HTTP server that establishes SSE connections but times out after 30 seconds to test client reconnection
- stderr: Server that logs to stderr
- structured-output: Demonstrates structuredContent responses with a simple echo tool
- ui: MCP Apps server with show-ui; the rendered UI button calls the get-time tool and shows the current time inline
- dual-content: Demonstrates different outputs for structuredContent and content in the same response
- everything: Comprehensive server testing all MCP features - tools with/without params, resources, prompts, elicitation, dynamic tools, roots echo, env vars

🚀 Quick Start: Automated Testing

For instant comprehensive testing, use the built-in AI agent testing prompt:

1. Start the everything server: npx @msfeldstein/mcp-test-servers everything
2. In Cursor, use the slash command: /test-everything
3. The AI will automatically execute all 20 test steps and provide a complete validation report