Getting Started
Introduction
MCP Playground is an open-source web app for discovering, inspecting, and interactively testing MCP servers — directly in your browser, with no local setup required.
What is MCP?
The Model Context Protocol (MCP) is an open standard that lets AI models connect to external tools, data sources, and services. Servers expose tools (functions AI can call), resources (structured data), and prompts (reusable instruction templates).
Examples of MCP servers: search engines, code interpreters, GitHub integrations, database connectors, web scrapers, and more.
What MCP Playground does
Browse the MCP Registry
Explore hundreds of publicly listed MCP servers on the /explore page. Filter by name, read descriptions, and see available packages.
Connect to any remote server
Paste a Streamable HTTP, SSE, or WebSocket endpoint URL on the /connect page. MCP Playground connects server-side and returns all available tools, resources, and prompts.
Run tools interactively
The Playground auto-generates a typed form from each tool's JSON Schema. Fill in the arguments and execute — results appear inline, and execution history is saved in your browser.
Check server quality
Visit the Quality Dashboard (/quality) to see how every live server in the registry scores. Servers are graded A–F on tool descriptions, schema completeness, and metadata quality.
Share what you find
Every execution is shareable. Copy a link that auto-connects, selects the tool, pre-fills arguments, and optionally auto-runs — so others can reproduce your exact session.
How it works (architecture)
All MCP connections are made server-side, never in the browser. Your browser talks to a Next.js API route, which connects to the remote MCP server using the official MCP SDK, and returns the result as JSON.
This means the MCP server URL never needs to be CORS-enabled, and your auth headers never leave the server-side request. Auth headers you provide are only stored in sessionStorage in your browser and sent in the POST body — they are never persisted on our servers.
Supported transports
Streamable HTTP
Tried first on every connection. Recommended for new servers.
SSE (Server-Sent Events)
Automatic fallback if Streamable HTTP fails.
stdio (local process)
Not directly supported, but you can bridge it with supergateway.
WebSocket
Use ws:// or wss:// URLs.