Tools: I Built A Free Tool-like Playground For Testing Mcp Servers - No...

If you've been building with Model Context Protocol (MCP) recently, you probably know the pain:

“Is my MCP server actually working?” “Did I implement the tool correctly?” “Why is Claude Desktop not picking up my tools?”

You end up writing custom test scripts, digging through logs, or manually crafting JSON-RPC requests with curl. It’s tedious.

So I built MCP Playground Online — a free, browser-based tool to test and debug MCP servers, inspired by how Postman changed REST API development.

Model Context Protocol (MCP) is an open standard that allows AI models to connect to external tools, APIs, and data sources in a structured way.

You can think of MCP as a universal adapter between AI systems and real-world capabilities:

Tools → Functions the AI can call (e.g., search_github, send_email)

Resources → Data the AI can read (e.g., files, database records)

Under the hood, MCP uses JSON-RPC 2.0, which is powerful — but not fun to test manually.

You can execute tools directly from the UI using a JSON editor — no scripts or CLI needed.

Source: Dev.to