MCP Playground

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Tagline:Test and explore MCP servers

Updated:September 5, 2026

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What is MCP Playground?

MCP Playground is a free, open-source web tool for inspecting, testing, and debugging Model Context Protocol (MCP) servers. Connect to any remote server over Streamable HTTP, SSE, or WebSocket, then browse its tools, resources, and prompts with auto-generated argument forms. No local install or setup is required — everything runs in the browser.

How to use MCP Playground?

1. Open MCP Playground in your browser. 2. Click Add Server and paste your MCP server's HTTP, SSE, or WebSocket URL. 3. Add any required auth headers (Bearer token, API key, or OAuth). 4. Inspect the server's tools, resources, and prompts, then run them with the auto-generated form and review the response.

MCP Playground Core Features

Connect & Inspect

Connect to any remote MCP server via Streamable HTTP, SSE, or WebSocket. View every tool, resource, and prompt with its schema, plus server metadata such as name, version, and protocol version.

Interactive Tool Testing

Run any tool from the sidebar using an auto-generated form built from its JSON Schema. Execute with custom arguments and review the full response and execution history.

Schema Linter

Grade any MCP server A–F across 15+ lint rules covering tool descriptions, JSON Schema completeness, and token cost estimates.

In-Browser Sandbox

Run npm MCP servers directly in your browser with WebContainers — no Node.js install, no terminal, and nothing leaves your tab.

Traffic Inspector

See every JSON-RPC message sent between client and server and debug protocol issues visually, with detailed request and response logs.

Public REST API

Programmatic access to inspect, lint, health-check, and browse the MCP registry. CORS-enabled with rate limiting for scripts and CI pipelines.

CLI & CI Integration

Run mcpx lint in your terminal and gate deployments on grade, token budget, or score regression in GitHub Actions, GitLab CI, or any CI system.

Share & Embed

Create shareable links that auto-run with pre-filled arguments, embed iframes in your docs, and add README badges for instant demos.

MCP Playground Use Cases

Test new MCP endpoints before pushing them to production

Debug server integrations by tracing request and response flows

Experiment with prompt templates and optimize AI model interactions

Validate that servers comply with the MCP specification during QA

Teach the Model Context Protocol with a hands-on, visual interface

Compare server behavior across dev, staging, and production from one place

MCP Playground Frequently Asked Questions

How do I connect to a private MCP server?

Click Add Server in the sidebar, enter your server's HTTP, SSE, or WebSocket endpoint, and add auth headers (Bearer token, API key, or OAuth) in the security panel. Connections are encrypted over HTTPS and credentials stay in your browser's session storage.

What transports does MCP Playground support?

It supports Streamable HTTP (tried first), SSE as an automatic fallback, and WebSocket for servers that use ws:// or wss:// URLs. All connections are made server-side through a Next.js API route.

Is my data secure when testing servers?

Auth headers are stored only in your browser's session storage and forwarded to your MCP server — they are never persisted to our servers. OAuth credentials are encrypted with AES-256-GCM.

Can I test a local stdio MCP server?

Localhost URLs are blocked in production. Use a tool like supergateway to expose a local stdio server over HTTP, then connect to that endpoint from the playground.

What are curated servers?

Curated servers are pre-configured MCP endpoints for common workflows like code search (Grep) and documentation retrieval (Context7). You can clone them into custom servers and override parameters, but cannot edit the base configuration.

MCP Playground Product Background & Official Links

MCP Playground Support Email & Customer service contact & Refund contact etc.

More Contact, visit the about us page(https://www.mcpplayground.tech/docs)

MCP Playground Team Info

MCP Playground Team name: emergent-lab

MCP Playground Developer Type: team

More about MCP Playground, Please visit the about us page(https://www.mcpplayground.tech/docs)

MCP Playground Pricing

MCP Playground Pricing Link: https://www.mcpplayground.tech/about

MCP Playground GitHub

MCP Playground GitHub Link: https://github.com/emergent-lab/mcp-playground

MCP Playground Pricing & Plans

Free

Connect and test unlimited MCP servers
Interactive tool, resource, and prompt explorer
Schema linter and traffic inspector
Public REST API and CLI access

Subscribe & upgrade now

Commercial License

contact

Contact sales

Use modified versions in closed-source products
Covers AGPL obligations for commercial use
Email the team for terms and pricing