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name: mcp-inspector description: Test Model Context Protocol (MCP) servers using the MCP Inspector CLI

MCP Inspector Testing Skill

Quick testing for MCP servers (stdio, HTTP, SSE). Run Inspector CLI commands to validate tools, resources, and prompts.

Quick Start

Copy# Basic tool test (local server)
npx @modelcontextprotocol/inspector --cli node build/index.js --method tools/list

# Call a tool
npx @modelcontextprotocol/inspector --cli node build/index.js \
  --method tools/call --tool-name mytool --tool-arg key=value

# Remote server (HTTP/SSE)
npx @modelcontextprotocol/inspector --cli https://server.com --method tools/list

Common Methods

Key CLI Flags

Transport:

• --cli - Enable non-interactive mode (required)
• --transport <stdio\|sse\|http> - Explicit transport type
• --server-url <url> - Server URL for SSE/HTTP

Testing:

• --method <name> - MCP method to call
• --tool-arg key=value - Tool arguments (repeatable)
• --uri <uri> - Resource URI
• --prompt-args key=value - Prompt arguments (repeatable)

Config:

• --config <path> - Load from mcp.json
• --server <name> - Select server from config
• -e KEY=VALUE - Set environment variable
• --header "Name: Value" - HTTP headers for remote servers

Transport Auto-Detection

• URLs ending in /mcp → HTTP (streamable)
• URLs ending in /sse → SSE
• No URL → stdio (local server)

Reference Docs

See references/ directory:

• cli-flags.md - Complete flag reference
• transports.md - stdio/SSE/HTTP details
• testing-methods.md - All methods with examples
• config-files.md - mcp.json patterns
• known-issues.md - Server vs CLI bugs

Language-Specific Examples

See examples/ directory:

• julia-stdio.md - Julia server testing
• remote-servers.md - HTTP/SSE testing, curl, mcp-remote

Official Docs

• MCP Inspector
• GitHub
• MCP Spec (2025-06-18)