mcptools MCP — Anwendungsfälle, Installieren & Live-Demo

Name: mcptools MCP Server
Author: f

Warum nutzen

Hauptfunktionen

Single binary, works with stdio/HTTP/SSE transports
mock creates fake MCP servers for testing clients
proxy wraps any shell command as an MCP tool
guard enforces allow/deny policies between client and server

Live-Demo

In der Praxis

mcptools.replay ▶ bereit

0/0

Installieren

Wählen Sie Ihren Client

~/Library/Application Support/Claude/claude_desktop_config.json · Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "mcptools": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/f/mcptools"
      ],
      "_inferred": true
    }
  }
}

Öffne Claude Desktop → Settings → Developer → Edit Config. Nach dem Speichern neu starten.

~/.cursor/mcp.json · .cursor/mcp.json

{
  "mcpServers": {
    "mcptools": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/f/mcptools"
      ],
      "_inferred": true
    }
  }
}

Cursor nutzt das gleiche mcpServers-Schema wie Claude Desktop. Projektkonfiguration schlägt die globale.

VS Code → Cline → MCP Servers → Edit

{
  "mcpServers": {
    "mcptools": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/f/mcptools"
      ],
      "_inferred": true
    }
  }
}

Klicken Sie auf das MCP-Servers-Symbol in der Cline-Seitenleiste, dann "Edit Configuration".

~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "mcptools": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/f/mcptools"
      ],
      "_inferred": true
    }
  }
}

Gleiche Struktur wie Claude Desktop. Windsurf neu starten zum Übernehmen.

~/.continue/config.json

{
  "mcpServers": [
    {
      "name": "mcptools",
      "command": "TODO",
      "args": [
        "See README: https://github.com/f/mcptools"
      ]
    }
  ]
}

Continue nutzt ein Array von Serverobjekten statt einer Map.

~/.config/zed/settings.json

{
  "context_servers": {
    "mcptools": {
      "command": {
        "path": "TODO",
        "args": [
          "See README: https://github.com/f/mcptools"
        ]
      }
    }
  }
}

In context_servers hinzufügen. Zed lädt beim Speichern neu.

claude mcp add mcptools -- TODO 'See README: https://github.com/f/mcptools'

Einzeiler. Prüfen mit claude mcp list. Entfernen mit claude mcp remove.

Anwendungsfälle

Praxisnahe Nutzung: mcptools

How to debug an MCP server with mcptools

👤 MCP server authors ⏱ ~15 min intermediate

Wann einsetzen: Your MCP works in Claude Desktop sometimes but fails silently — you need to see the raw wire traffic.

Voraussetzungen

mcptools installed — brew install f/mcptools/mcp or go install github.com/f/mcptools/cmd/mcp@latest

Ablauf

List tools on your server

Run mcp tools --transport stdio -- node ./my-server.js. Check tool names and schemas.✓ Kopiert

→ Clean list; if empty, the server didn't advertise tools correctly
Call a specific tool with raw args

Run mcp call my_tool --params '{"x":1}' -- node ./my-server.js and inspect the JSON response.✓ Kopiert

→ Tool output matches expected schema
Start an interactive shell

Run mcp shell -- node ./my-server.js and call tools manually.✓ Kopiert

→ REPL with tab-complete over your tools

Ergebnis: You see exactly what Claude sees — bugs that only reproduce in Claude become visible here.

Fallstricke

Server logs to stdout, corrupting the JSON-RPC stream — Route all logs to stderr. mcptools surfaces this — the hint is garbled JSON parse errors
Tool schema uses unsupported JSON Schema keywords — Stick to core draft-07; some clients reject $ref, allOf, etc.

Mock an MCP server to test an MCP client

👤 Client authors ⏱ ~20 min intermediate

Wann einsetzen: Your CI shouldn't depend on a real Sentry/GitHub server — you need a deterministic mock.

Ablauf

Write a mock spec

Create ./mock.yaml listing the tools you want to fake with canned responses.✓ Kopiert

→ YAML describing tool names + output templates
Run mcp mock

Run mcp mock --config ./mock.yaml --transport stdio and point your client at it.✓ Kopiert

→ Client sees a fully populated tool list; calls return canned data

Ergebnis: Hermetic tests that pass on airgapped CI.

Expose a shell command as an MCP tool without writing a server

👤 Ops, DIY hackers ⏱ ~10 min beginner

Wann einsetzen: You have a handy shell script and want Claude to call it — but writing a full MCP server feels overkill.

Ablauf

Wrap the script

Run mcp proxy register disk_usage --command 'df -h' and confirm it's advertised.✓ Kopiert

→ Tool disk_usage registered
Point Claude at mcp proxy

Configure Claude's mcpServers with mcp proxy serve.✓ Kopiert

→ Claude can call disk_usage and gets the df output

Ergebnis: Zero-code MCP tools for quick automations.

Fallstricke

Exposing unrestricted shell is a foot-gun — Use mcp guard to whitelist specific commands; never expose bash -c

Enforce allow/deny policies on an upstream MCP with mcptools guard

👤 Security-minded teams using third-party MCPs ⏱ ~20 min advanced

Wann einsetzen: You trust GitHub MCP for reads but don't want agents to create issues or delete branches.

Ablauf

Write a policy

Create a guard policy that allows list_* and get_* tools but denies everything else on the github server.✓ Kopiert

→ Policy file with explicit rules
Run guard

Run mcp guard --policy ./policy.yaml -- npx -y @modelcontextprotocol/server-github and point Claude at guard instead of the server directly.✓ Kopiert

→ Denied calls return a clear error, allowed calls proxy through

Ergebnis: A read-only façade in front of a powerful server — safer defaults.

Kombinationen

Mit anderen MCPs für 10-fache Wirkung

mcptools + hyper

Debug hyper-mcp plugin loading with mcp shell before wiring it into Claude

Use mcp shell to list plugins on my hyper-mcp host and test-call each tool.✓ Kopiert

mcptools + claude-code

Validate every MCP server in your Claude Code config with mcp tools

For each server in ~/.claude.json, run mcp tools to verify it starts and advertises a non-empty tool list.✓ Kopiert

Werkzeuge

Was dieses MCP bereitstellt

Werkzeug	Eingaben	Wann aufrufen	Kosten
mcp tools	--transport <stdio\|http\|sse>, -- <server-cmd>	Inspect a server's surface	0
mcp call	<tool-name> --params '<json>' -- <server-cmd>	Ad-hoc call without a client	1 tool call
mcp shell	-- <server-cmd>	Exploratory debugging	0
mcp mock	--config <yaml>	CI / client testing	0
mcp proxy	register <name> --command '<shell>'; serve	Wrap shell into MCP without code	0
mcp guard	--policy <yaml> -- <server-cmd>	Apply allow/deny to an upstream	0

Kosten & Limits

Was der Betrieb kostet

API-Kontingent: None — local CLI
Tokens pro Aufruf: N/A (not an MCP itself)
Kosten in €: Free, MIT
Tipp: Use --format json | jq to automate checks in CI

Sicherheit

Rechte, Secrets, Reichweite

Credential-Speicherung: Passes through to the proxied server; mcptools itself stores nothing

Datenabfluss: Only where the proxied/guarded server goes

Fehlerbehebung

Häufige Fehler und Lösungen

`mcp tools` hangs forever

Server is writing logs to stdout, corrupting the handshake. Redirect server logs to stderr

Prüfen: mcp tools --timeout 5s -- <cmd>

Binary not found after `go install`

Ensure $GOPATH/bin is on your PATH

Prüfen: which mcp

Guard policy matches nothing

Policy names must match tool names exactly (case-sensitive). Use mcp tools first to confirm names

Alternativen

mcptools vs. andere

Alternative	Wann stattdessen	Kompromiss
MCP Inspector	You prefer a GUI and are okay running a local web app	Heavier; less scriptable than a CLI
Raw jsonrpc via stdio	You're deep-debugging a protocol issue	Verbose; mcptools handles handshake for you

Mehr

Ressourcen

📖 Offizielle README auf GitHub lesen

🐙 Offene Issues ansehen

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