inspector

Overview

MCPJam Inspector provides a complete development environment for MCP servers, offering debugging tools, chat functionality, server inspection capabilities, and evaluation features. It supports multiple deployment options including a hosted web app, desktop applications, and a terminal interface. The platform enables developers to inspect JSON-RPC messages, test OAuth flows, run tools and resources manually, compare LLM models, and integrate with CI/CD pipelines. It eliminates the need for ngrok or ChatGPT subscriptions, providing a faster iteration cycle for MCP projects.

Try asking AI

After installing, here are 5 things you can ask your AI assistant:

• probe_server

  Probe MCP servers for connectivity and basic information

  Try:Probe my server at localhost:8080Try:Check if server is responsive
• run_oauth_checks

  Run OAuth conformance checks against MCP servers

  Try:Test OAuth flow for my serverTry:Verify OAuth 11-25 compliance
• inspect_tools

  List and examine tools exposed by an MCP server

  Try:Show all available toolsTry:Describe the query_postgres tool
• execute_tool

  Manually invoke a tool from an MCP server

  Try:Run the list_files tool with path=/homeTry:Execute create_github_issue
• inspect_resources

  List and examine resources exposed by an MCP server

  Try:Show all available resourcesTry:Describe the database_schema resource
• list_prompts

  List prompts available from an MCP server

  Try:Show all promptsTry:Display the code_review prompt
• run_evals

  Run evaluation tests across multiple LLMs

  Try:Run evaluation on test casesTry:Test accuracy across GPT-4 and Claude
• create_test_case

  Create a test case with expected tool calls for evaluation

  Try:Create a test case for customer lookupTry:Make test for data analysis query
• snapshot_server

  Create a snapshot of server capabilities for testing

  Try:Snapshot server before changesTry:Capture tool and resource definitions
• debug_json_rpc

  Debug JSON-RPC messages between client and server

  Try:Show all JSON-RPC messagesTry:Debug failed tool call
• compare_models

  Compare responses from multiple LLMs

  Try:Compare GPT-4 vs Claude on same promptTry:Show differences in responses
• create_workspace

  Create a shared workspace for team server testing

  Try:Create workspace for team projectTry:Share server configuration with team

Note: Tool names inferred from feature descriptions and capabilities mentioned throughout the documentation. The README doesn't have a dedicated 'Tools' section but describes various functionalities that would be exposed as MCP tools.

Comparable tools

Installation

npx @mcpjam/inspector@latest

docker run -p 127.0.0.1:6274:6274 mcpjam/mcp-inspector

FAQ

What MCP protocols does MCPJam support?

MCPJam supports multiple versions of the MCP OAuth spec (03-26, 06-18, and 11-25), including client pre-registration, Dynamic Client Registration (DCR), and Client ID Metadata Documents (CIMD).

Can I use MCPJam with my local STDIO MCP server?

Yes, MCPJam supports local STDIO servers when using the desktop app or terminal interface. The hosted web app only supports HTTPS MCP server URLs.

On Hacker News

Recent discussion from the developer community.

• We built the first MCP client with Ollama support▲ 4
  Story by matt8p · 2025-06-27
• Show HN: I built a better MCP inspector to debug MCP servers▲ 3💬 1
  Story by matt8p · 2025-06-17
• MCPJam: Open-Source Postman for MCP▲ 2💬 1
  Story by matt8p · 2025-07-01

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