MCP Playground

MCP Playground is an interactive playground for the Model Context Protocol. It is built to test remote MCP servers in the browser, letting users paste a server URL, inspect what it exposes, and run tools live without installation.

The service supports remote endpoints over Streamable HTTP, SSE, and WebSocket, and it says it can auto-detect the right protocol or connect directly via ws://. It presents the tools, resources, and prompts a server exposes, shows full JSON Schema, and runs them through auto-generated forms. The page also lists a schema linter for grading MCP servers A–F with 15+ lint rules, and a quality dashboard for browsing registry-wide grades. A public REST API is mentioned for inspecting, linting, and health-checking MCP servers, and the site also offers an in-browser sandbox for stdio-based npm MCP servers via WebContainers.

MCP Playground is aimed at people working with MCP servers, including server authors and developers. The page also offers a public registry view with 852+ servers, examples for testing live servers, and an embeddable “Try in MCP Playground” badge for README files. It says authenticated servers can be used with a user’s own API key and authorization headers.

The site is delivered in the browser and requires no installation. It is built on the official MCP Registry and the official MCP SDK, and it is open source under the AGPL v3 license. The page also links to an associated mcpx CLI and CI workflow for running the linter in terminals and pipelines, with mentions of GitHub Actions, GitLab CI, and other CI systems.