mcptools MCP — Cas d'usage, Installer & Démo en direct

Name: mcptools MCP Server
Author: f

Pourquoi l'utiliser

Fonctionnalités clés

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

Démo en direct

Aperçu en pratique

mcptools.replay ▶ prêt

0/0

Installer

Choisissez votre 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
    }
  }
}

Ouvrez Claude Desktop → Settings → Developer → Edit Config. Redémarrez après avoir enregistré.

~/.cursor/mcp.json · .cursor/mcp.json

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

Cursor utilise le même schéma mcpServers que Claude Desktop. La config projet l'emporte sur la globale.

VS Code → Cline → MCP Servers → Edit

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

Cliquez sur l'icône MCP Servers dans la barre latérale Cline, puis "Edit Configuration".

~/.codeium/windsurf/mcp_config.json

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

Même format que Claude Desktop. Redémarrez Windsurf pour appliquer.

~/.continue/config.json

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

Continue utilise un tableau d'objets serveur plutôt qu'une map.

~/.config/zed/settings.json

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

Ajoutez dans context_servers. Zed recharge à chaud à la sauvegarde.

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

Une seule ligne. Vérifiez avec claude mcp list. Supprimez avec claude mcp remove.

Cas d'usage

Usages concrets : mcptools

How to debug an MCP server with mcptools

👤 MCP server authors ⏱ ~15 min intermediate

Quand l'utiliser : Your MCP works in Claude Desktop sometimes but fails silently — you need to see the raw wire traffic.

Prérequis

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

Déroulement

List tools on your server

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

→ 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.✓ Copié

→ Tool output matches expected schema
Start an interactive shell

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

→ REPL with tab-complete over your tools

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

Pièges

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

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

Déroulement

Write a mock spec

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

→ YAML describing tool names + output templates
Run mcp mock

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

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

Résultat : 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

Quand l'utiliser : You have a handy shell script and want Claude to call it — but writing a full MCP server feels overkill.

Déroulement

Wrap the script

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

→ Tool disk_usage registered
Point Claude at mcp proxy

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

→ Claude can call disk_usage and gets the df output

Résultat : Zero-code MCP tools for quick automations.

Pièges

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

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

Déroulement

Write a policy

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

→ 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.✓ Copié

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

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

Combinaisons

Associez-le à d'autres MCPs pour un effet X10

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.✓ Copié

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.✓ Copié

Outils

Ce que ce MCP expose

Outil	Entrées	Quand appeler	Coût
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

Coût et limites

Coût d'exécution

Quota d'API: None — local CLI
Tokens par appel: N/A (not an MCP itself)
Monétaire: Free, MIT
Astuce: Use --format json | jq to automate checks in CI

Sécurité

Permissions, secrets, portée

Stockage des identifiants : Passes through to the proxied server; mcptools itself stores nothing

Sortie de données : Only where the proxied/guarded server goes

Dépannage

Erreurs courantes et correctifs

`mcp tools` hangs forever

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

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

Binary not found after `go install`

Ensure $GOPATH/bin is on your PATH

Vérifier : which mcp

Guard policy matches nothing

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

Alternatives

mcptools vs autres

Alternative	Quand l'utiliser	Compromis
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

Plus

Ressources

📖 Lire le README officiel sur GitHub

🐙 Voir les issues ouvertes

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