MCP Endpoint Shield

MCP Endpoint Shield provides runtime security and auto-discovery of local MCP servers configured on your machine. It acts as a protective layer between the MCP client (e.g., Cursor, VS Code, Claude) and the MCP servers—requiring no changes to your setup.

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✨ Features

• ✅ Continuous safety checks on all requests and responses to the MCP servers

• ✅ Automatic blocking of unsafe interactions (via standard JSON-RPC errors)

• ✅ Works out-of-the-box with popular MCP clients (Cursor, VS Code, Claude)

• ✅ Zero changes required in your MCP server

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📦 Installation

• The tool is provided as an installable binary for your platform (Linux, macOS, Windows).

• Download the binary from the official release page and place it in your system path ($PATH) for easy CLI access.

Example (macOS/Linux):

chmod +x mcp-endpoint-shield
mv mcp-endpoint-shield /usr/local/bin/

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🔍 Auto-Detection

Akto MCP Endpoint Shield automatically detects MCP client configurations:

• Cursor → Reads ~/.cursor/mcp.json

• Visual Studio Code → Reads .vscode/mcp.json inside your workspace

• Claude Desktop → Reads Claude’s MCP config JSON

For each detected MCP server config:

1. The JSON file is parsed.

2. Each server entry is automatically wrapped with Akto MCP Endpoint Shield.

3. Your MCP clients transparently run through the shield without requiring manual reconfiguration.

👉 You don’t need to manually edit your MCP config files — the wrapper handles this for you.

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📄 Example — Cursor mcp.json

Original file (before wrapping):

{
  "mcpServers": {
    "playwright-mcp": {
      "command": "npx",
      "args": [
        "-y"
        "@playwright/mcp@latest"
      ]
    }
  }
}

Automatically wrapped file (after Akto MCP Endpoint Shield):

{
  "mcpServers": {
    "playwright-mcp-endpoint-shield": {
      "command": "mcp-endpoint-shield",
      "args": [
        "stdio",
        "--name",
        "playwright-mcp",
        "--akto-api-token",
        "<your akto api token>",
        "--exec",
        "npx",
        "-y",
        "@playwright/mcp@latest"
      ]
    }
  }
}

What changed:

• The server is renamed from playwright-mcp → playwright-mcp-endpoint-shield.

• mcp-endpoint-shield is now the entry command.

• Original server command (npx @playwright/mcp@latest) is passed through --exec.

• Security flags (--akto-api-token) are automatically injected.

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🚀 Quick Start (Manual Run)

If you want to run manually (instead of auto-detection):

mcp-endpoint-shield stdio --name <project_name> --akto-api-token <token> --exec <your_mcp_server_command> [args...]

Examples

• Python server:

  mcp-endpoint-shield stdio --name my-mcp --akto-api-token <TOKEN> --exec uv run server.py

• Dockerized server:

  mcp-endpoint-shield stdio --name my-mcp --akto-api-token <TOKEN> --env AKTO_API_KEY=<TOKEN> --exec docker run --rm -i -e AKTO_API_KEY=<TOKEN> your/mcp-image:latest

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⚙️ Common Flags

• --name <project_name> → Friendly label used in logs and insights

• --akto-api-token <token> → Your Akto API token

• --exec <command> [args...] → Command to start your MCP server

• --env KEY=VALUE (repeatable) → Pass additional environment variables to the MCP process

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🛠 How It Works (Behind the Scenes)

1. The wrapper launches your MCP server.

2. Every request/response line is intercepted.

3. Safe traffic passes through unchanged.

4. Unsafe traffic is blocked, returning a clear JSON-RPC error to the client.

5. Metadata is recorded (lightweight, opt-in) to improve detection and insights.

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📜 Logging

• Location: $HOME/.akto/mcp_endpoint_shield.log

• Format: human-readable text logs

• Includes: project name (--name) for easy filtering

• Rotation: automatic (size-based) to prevent unbounded growth

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💻 Using with Cursor (at a glance)

• In Cursor settings, configure your MCP server to run through the wrapper.

• Place your original MCP server command after --exec.

• (Optional: Add a diagram/screenshot here for clarity.)

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🧩 Troubleshooting

Issue: Auto-detection didn’t work ➡ Cause: Custom MCP config location or unsupported client. ➡ Fix: Run your server manually with --exec.

Issue: Unexpected end of JSON input ➡ Cause: Your MCP server is writing non-protocol logs to stdout. ➡ Fix: Use stderr for logs instead.

Issue: ERROR writing to MCP stdin: file already closed ➡ Cause: MCP server exited or closed stdin prematurely. ➡ Fix: Run your server standalone to confirm stability.

Issue: No insights appearing ➡ Cause: Some tools don’t use standard JSON-RPC IDs. ➡ Fix: Safety still applies, but insights may be limited.

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🔒 Guarantees

• ✅ Transparency: Safe traffic is never altered.

• ✅ Clarity: Unsafe traffic always results in a clear JSON-RPC error.

• ✅ Minimal footprint: Designed to stay invisible unless an issue occurs.

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Get Support for your Akto setup

There are multiple ways to request support from Akto. We are 24X7 available on the following:

1. In-app intercom support. Message us with your query on intercom in Akto dashboard and someone will reply.

2. Join our discord channel for community support.

3. Contact [email protected] for email support.

4. Contact us here.