MCP Inspector

by namnhutdinh · Developer Tools

Manifest V3 Free

View in Chrome Web Store Data as of 16 Oct 2026

Inspect MCP servers you choose — call tools, browse resources, and watch JSON-RPC traffic.

Users

+22 in 30 days

Rating

5.0 / 5

+5.00 in 30 days

Ratings

+5 in 30 days

Store rank

#145K

#121K among extensions

Version

0.1.1

updated 15 Sep 2026

Users

monthly, 1 months

Latest, 16 Oct 2026: 22 usersMove the mouse over the chart for any month

Ratings count

monthly, 1 months

Latest, 16 Oct 2026: 5 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About MCP Inspector

MCP Inspector is a side-panel developer tool for building, testing, and debugging Model Context Protocol (MCP) servers. Connect to your own server (Streamable HTTP, legacy SSE, or WebSocket), or click Connect on the built-in demo to test the UI instantly without local setup. KEY FEATURES: • Inspect Server Details: View protocol versions, instructions, and reported capabilities at a glance. • Interactive Tool Execution: Call tools via dynamic forms automatically generated from JSON Schemas. • Resources & Prompts: Read server resources, inspect URI templates, supply prompt arguments, and preview rendered outputs. • Traffic Inspector: Monitor JSON-RPC frames in real time with latency metrics, payload size, filtering, and one-click copy. • Integrated OAuth 2.1: Handles authorization code + PKCE in Chrome’s native auth window on 401 responses, storing tokens locally per server. OPTIONAL & ADVANCED CAPABILITIES: • Natural Language Testing (Ask): Add your Gemini API key to test server tools interactively. The extension will not send prompts or tool definitions anywhere until you supply a key and opt in. • Page Mode (Experimental): Inspect WebMCP tools on the active tab (document.modelContext) with explicit site permission. Requires Chrome 150+ and chrome://flags/#enable-webmcp-testing. • Stdio Transport: Connect to local Node.js / npx servers via an optional native messaging host (configured separately; not required for standard web transports). PRIVACY & PERMISSIONS: • Server mode runs on Chrome 116+ without injecting scripts into websites. • Contains zero ads, trackers, analytics, or affiliate links.