Free MCP Developer Tools

Browser-based utilities for building, inspecting, validating, and optimizing Model Context Protocol (MCP) servers and client configurations. 100% private — nothing leaves your browser.
Stack Builder

MCP Stack Builder

Select your favorite MCP tools and export a single unified claude_desktop_config.json or Cursor setup in seconds with interactive live previews.

Build Your Stack
Comparison

Side-by-Side Server Comparison

Compare 2 to 4 MCP servers side-by-side on tool capabilities, installation requirements, GitHub stars, and security posture.

Compare Servers
Code Generator

OpenAPI to MCP Generator

Convert OpenAPI 3.0/3.1 or Swagger specs into runnable TypeScript SDK or Python FastMCP server code automatically.

Generate Code
Protocol Debugger

Protocol Inspector & Debugger

Inspect raw JSON-RPC 2.0 payloads, validate schema compliance, catch protocol errors, and preview live AI client rendering.

Inspect Payloads
Configuration

Config Generator

Build a ready-to-paste claude_desktop_config.json (or Cursor/VS Code/Windsurf equivalent) from directory servers or custom setups.

Generate Config
Security & Audit

Config Auditor & Merger

Audit your MCP client JSON configs for unreplaced API key placeholders, syntax issues, and merge directory servers in 1 click.

Audit Configs
Live Testing

Interactive MCP Playground

Test remote JSON-RPC 2.0 MCP endpoints in your browser — execute initialize, tools/list, and tools/call requests with live logging.

Open Playground
Schema Validator

Config Validator

Paste your MCP config JSON and catch syntax errors, missing fields, and path issues before restarting your client.

Validate JSON
Context Budget

Token Cost Calculator

Estimate how much of your model's context window your installed MCP servers' tool schemas consume on every turn.

Calculate Overhead