MCP Inspector Tool
Test, debug, and validate any MCP server instantly — no setup required. Paste a URL, pick an action, and inspect the response in real time.
Free to use · 50 requests/hour as a guest · Sign in for more
Powered by DataGrout · 50 requests/hour as a guest · Create a free account for a higher limit
The fastest way to validate an MCP server
The Model Context Protocol (MCP) is an open standard that lets AI agents discover and call tools exposed by any service. But before you wire an MCP server into your agent, you need to know it actually works — that the handshake completes, tools are listed correctly, and tool calls return the right results.
Connect
Enter any MCP server URL. The inspector initializes the connection and confirms the handshake in milliseconds.
Inspect
List every tool the server exposes, see their schemas, and call them directly — without writing a single line of code.
Validate
Confirm auth works, responses match expected schemas, and latency is acceptable before connecting to production agents.
Without an inspector, debugging an MCP server means parsing raw HTTP logs, writing throwaway test scripts, or connecting a full agent and hoping the output tells you what went wrong. That's slow, and it conflates two separate problems: "is my MCP server correct?" and "is my agent logic correct?"
The MCP Inspector separates them. You can confirm that your server is working — correct protocol version, all tools listed with their full input/output schemas, auth accepted, and tool calls returning valid JSON — before your agent ever touches it. Toggle Intelligent Interface to see how your server presents tools in semantic discovery mode rather than the full flat list. Every request is also exportable as a cURL command, making it easy to add server validation to CI pipelines or share reproducible test cases with teammates.
What the inspector does
Everything you need to validate an MCP server from first connection to tool execution.
Test any MCP server by URL
Paste any MCP server endpoint and connect instantly. Works with local dev servers, staging environments, and production endpoints.
Multiple authentication methods
Supports No Auth, Bearer tokens, and other common auth schemes — so you can test secured servers without workarounds.
Full MCP action coverage
Run Initialize (server info), List Tools, Call Tool, List Resources, and more — covering the complete MCP protocol surface.
Intelligent Interface mode
Toggle Intelligent Interface and your server's full tool list is replaced with a compact semantic discovery surface. Agents find what they need by goal instead of parsing every tool name — dramatically reducing context overhead.
Copy JSON & export as cURL
Every response can be copied as raw JSON or exported as a ready-to-run cURL command — making it easy to replicate calls in CI or share with teammates.
Inline schema docs before you execute
Select any tool in Call Tool mode and the inspector renders its input schema inline — parameter names, types, and descriptions — before you run anything. No cross-referencing external API docs required.
Live tool execution with a parameter editor
Construct real JSON arguments in the built-in parameter editor and execute an actual tool call against your server. You're not just reading schemas — you're testing live behavior end to end.
Real-time response log with latency
Every request is timestamped with measured latency. Scroll back through your session history to compare responses across calls without re-running requests.
How to use the MCP Inspector
Four steps from a blank form to a validated MCP server.
Enter your MCP server URL
Paste the full endpoint URL of your MCP server (e.g. https://gateway.example.ai/servers/.../mcp). The tool connects immediately.
Choose an authentication method
Choose from No Authentication, Bearer token, Basic auth, OAuth 2.0 (paste an existing token), or OAuth 2.1 (full authorization code flow with PKCE). DataGrout-hosted servers are pre-configured. Credentials are kept in-memory for the current session only and are never persisted.
Select an MCP action
Pick from Initialize (Get Server Info), List Tools, Call Tool, or other MCP protocol actions from the dropdown. With List Tools, expand any result to inspect its full input and output JSON schemas. With Call Tool, select a tool, read its inline parameter docs, fill in JSON arguments, and execute a real call against your server. Toggle Intelligent Interface to see how the server presents its tools in semantic discovery mode instead of the full flat list.
Execute and inspect the response
Click Execute Request. The Response Log updates in real time — review the JSON, check latency, copy the response, or export the call as a cURL command.
Your server passes inspection. Now connect it to everything.
The MCP Inspector confirms your server works. DataGrout Hub is what happens next — a single governed endpoint that connects your MCP server alongside 1,000+ other enterprise tools, with mTLS identity, semantic tool discovery, policy enforcement, and tamper-evident audit trails baked in.
- Multiplex your server with Salesforce, QuickBooks, and more
- Agents discover tools by goal — not by browsing your full tool list
- Credential vaulting, PII redaction, and human approval built in
- Private Connectors for on-prem servers (no firewall changes)
MCP Inspector → DataGrout Hub
Frequently asked questions
What is an MCP inspector?
An MCP inspector is a debugging tool that lets you connect to any Model Context Protocol (MCP) server and interactively run protocol actions — initialize, list tools, call tools, and more. It's the fastest way to validate that an MCP server is working correctly before wiring it into an AI agent.
What is the Model Context Protocol (MCP)?
MCP is an open protocol that standardizes how AI agents discover and call tools exposed by external services. Instead of every agent implementing its own API glue code, MCP provides a common interface: agents call tools, tools return results, and the protocol handles the rest.
Can I test a local MCP server?
Yes. If your local server is accessible via a URL (including localhost with a tunnel like ngrok), you can paste it directly into the MCP Server URL field and test it immediately.
What MCP actions does the inspector support?
The inspector supports the core MCP protocol actions including Initialize (Get Server Info), List Tools, Call Tool, List Resources, and List Prompts — giving you full coverage of what your MCP server exposes.
What is the Intelligent Interface option?
Intelligent Interface is a server-side mode where agents discover tools dynamically using a semantic 'discover' + 'perform' pair instead of receiving the full tool list. This eliminates the N×M context explosion problem when a server exposes hundreds of tools. Toggle it in the inspector to see the difference in response structure.
Is this tool free to use?
Yes. The MCP Inspector is free with 50 requests per hour as an anonymous user. Create a free DataGrout account for a higher limit.
How does MCP Inspector relate to DataGrout?
DataGrout built this tool for the developer community. Once your MCP server is tested and working, DataGrout Hub lets you connect it alongside 1,000+ other enterprise tools under a single governed endpoint — with mTLS identity, semantic discovery, policy enforcement, and audit trails.
Ready to connect your MCP server to enterprise AI?
DataGrout Hub is the governed, production-grade layer that makes MCP servers enterprise-ready.