I Built Postman for MCP Servers Because Debugging JSON-RPC Shouldn't Be Hell

Naman Gupta — Sun, 26 Apr 2026 08:21:24 +0000

If you're building with the Model Context Protocol (MCP), you already know the pain.

You write a server. You wire it up to Claude, Cursor, or your own agent. And then... you spend the next 3 hours running curl commands, squinting at raw JSON-RPC payloads, and guessing why your tool schema isn't being picked up.

There had to be a better way. So I built one.

Meet MCPHub — The Postman for MCP

Live: mcp-hub-pi.vercel.app
GitHub: github.com/namanxdev/MCPHub
NPM Agent: @naman_411/mcphub-agent

It's an open-source platform to develop, debug, and deploy MCP servers without losing your sanity. No bloat. No hand-holding. Just the tools you actually need.

The Problem: MCP Debugging Is Still Stuck in 2010

MCP is genuinely the future of how LLMs interact with the world. But the developer experience? It's basically:

Write a server
Fire up your AI client
Hope it works
If it doesn't, add console.log everywhere and pray

There's zero visibility into the wire protocol. No easy way to test individual tools. No metrics to tell you if your server is slow or just broken.

That friction kills iteration speed. And when you're building AI agents, iteration speed is everything.

What MCPHub Actually Does

🛠️ The Playground — Stop Writing `curl` Commands

Paste your SSE endpoint or local command. MCPHub auto-generates clean input forms directly from your tool's JSON Schema.

Fill in arguments → Hit Run → See the raw response instantly.

No more hand-crafting JSON-RPC payloads. No more guessing if your schema is malformed.

🕵️‍♂️ Protocol Inspector — See Everything Over the Wire

Every single JSON-RPC message is captured, parsed, and displayed with syntax highlighting. Filter by direction (client → server or vice versa), inspect headers, and spot malformed tool definitions before they hit production.

It's the transparency MCP development has been missing.

🖥️ Desktop Agent — Your Localhost, But Cloud-Connected

Here's the catch-22: your deployed playground can't talk to localhost. The @naman_411/mcphub-agent npm package fixes that.

npm install -g @naman_411/mcphub-agent
mcphub-agent start

A WebSocket bridge connects your local MCP servers directly to the MCPHub web app. Green banner pops up. Toggle it on. Done.

📊 Health Dashboard — Know Before Your Users Do

Real P50 / P95 / P99 latency metrics. Error rate tracking. Uptime monitoring per tool. Not vanity numbers actual production signals.

🌐 Public Registry — Discover & Test Community Servers

Searchable directory of community MCP servers with live status badges. One-click testing. No clone-and-run required.

The Stack (For The Curious)

Layer	Tech
Framework	Next.js 16 (App Router, React 19)
Language	TypeScript 5
Styling	Tailwind CSS 4 + shadcn/ui
State	Zustand 5
Database	Neon PostgreSQL + Drizzle ORM
Auth	NextAuth.js v5 (GitHub + Google)
MCP SDK	@modelcontextprotocol/sdk
Charts	Recharts
Deploy	Vercel

Why Open Source?

Because MCP itself is an open protocol. The tooling around it should be too.

I'm building this entirely in public. Break it, fork it, tell me what's missing. The roadmap is driven by real pain points, not investor decks.

Try It In 30 Seconds

Web App: mcp-hub-pi.vercel.app
Drop a star ⭐ on GitHub if it saves you time
Local bridge: npx @naman_411/mcphub-agent start

If you've been wrestling with MCP servers, this is for you. If you haven't started yet this is your excuse to.

What's the most painful part of MCP development for you right now? Drop it in the comments. I might just build the fix next.

DEV Community: Naman Gupta