Enkrypt AI Secure MCP Gateway

Overview

This Secure MCP Gateway is built with authentication, automatic tool discovery, caching, and guardrail enforcement.

It sits between your MCP client and MCP servers. So, by it's nature it itself also acts as an MCP server as well as an MCP client :)

When your MCP client connects to the Gateway, it acts as an MCP server. When the Gateway connects to the actual MCP server, it acts as an MCP client.

Table of Contents

• Features 🚀
  • Guardrails 🔒 🚧
• High level steps of how the MCP Gateway works 🪜
• Prerequisites 🧩
  • Optional Protection with Enkrypt Guardrails 🔒
• Gateway Setup 👨‍💻
  • Check versions 🔍
  • Local Installation 📥
    • 1. Clone the repo, setup virtual environment and install dependencies 📥
    • 2. Run the setup script 📥
    • 3. Example MCP config file generated 📄
    • 4. Restart Claude Desktop to run the Gateway 🔄
    • 5. Example prompts 💬
    • 6. Example config file generated ⚙️
    • 7. Edit the Gateway config as needed ✏️
  • Remote Installation 📥
• (Optional) Add GitHub MCP Server to the Gateway 🤖
• (Optional) Protect GitHub MCP Server and Test Echo Server with Enkrypt Guardrails for FREE 🔒
  • Create a Guardrail in Enkrypt App 🔒
  • Get Enkrypt API Key 🔑
  • Add API Key and the Guardrail to Config File ⚙️
  • Test Guardrails 🔒
  • NOTE: Fine Tune Guardrails 🔧
• Recommendations for using Guardrails 💡
• Setup Other MCP Clients 🤖
  • Cursor ⬡
• Other Tools Available 🔧
  • Get Cache Status 📊
  • Clear Cache 🧹
• Deployment Patterns 🪂
• Known Issues being worked on 🏗️
• Known Limitations ⚠️
• License 📝

Features

Below are the list of features Enkrypt AI Secure MCP Gateway provides:

1. Authentication: We use Unique Key to authenticate with the Gateway. We also use Enkrypt API Key if you want to protect your MCPs with Enkrypt Guardrails

2. Ease of use: You can configure all your MCP servers locally in the config file or better yet in Enkrypt (Coming soon) and use them in the Gateway by using their name

3. Dynamic Tool Discovery: The Gateway discovers tools from the MCP servers dynamically and makes them available to the MCP client

4. Restrict Tool Invocation: If you don't want all tools to be accessible of a an MCP server, you can restrict them by explicitly mentioning the tools in the Gateway config so that only the allowed tools are accessible to the MCP client

5. Caching: We cache the user gateway config and tools discovered from various MCP servers locally or in an external cache server like KeyDB if configured to improve performance

6. Guardrails: You can configure guardrails for each MCP server in Enkrypt both on input side (before sending the request to the MCP server) and output side (after receiving the response from the MCP server)

7. Logging: We log every request and response from the Gateway locally in your MCP logs and also forward them to Enkrypt (Coming soon) for monitoring. This enables you to see all the calls made in your account, servers used, tools invoked, requests blocked, etc.

Guardrails

Input Protection: Topic detection, NSFW filtering, toxicity detection, injection attack prevention, keyword detection, policy violation detection, bias detection, and PII redaction (More coming soon like system prompt protection, copyright protection, etc.)

Output Protection: All input protections plus adherence checking and relevancy validation (More coming soon like hallucination detection, etc.) We also auto unredact the response if it was redacted on input.

High level steps of how the MCP Gateway works

1. Your MCP client connects to the Secure MCP Gateway server with API Key (handled by src/gateway.py).

2. Gateway server fetches gateway config from local enkrypt_mcp_config.json file or remote Enkrypt Auth server (Coming soon).

   • It caches the config locally or in an external cache server like KeyDB if configured to improve performance.

3. If input guardrails are enabled, request is validated before the tool call (handled by src/guardrail.py).

   • Request is blocked if it violates any of the configured guardrails and the specific detector is configured to block.

4. Requests are forwarded to the Gateway Client (handled by src/client.py).

5. The Gateway client forwards the request to the appropriate MCP server (handled by src/client.py).

6. The MCP server processes the request and returns the response to the Gateway client.

7. If it was a discover tools call, the Gateway client caches the tools locally or in an external cache server like KeyDB if configured. It then forwards the response to the Gateway server.

8. The Gateway server receives the response from the Gateway client and if output guardrails are enabled, it validates the response against the configured guardrails (handled by src/guardrail.py).

   • Response is blocked if it violates any of the configured guardrails and the specific detector is configured to block.

9. The Gateway server forwards the response back to the MCP client if everything is fine.

Prerequisites

• Git 2.43 or higher

• Python 3.11 or higher installed on your system and is accessible from the command line using either python or python3 command

• pip 25.0.1 or higher is installed on your system and is accessible from the command line using either pip or python -m pip command

• uv 0.7.9 or higher is installed on your system and is accessible from the command line using either uv or python -m uv command

<!-- - Set PYTHONPATH in your system environment variables

• For reference, see How to Add Python to PATH on Windows, Linux, and Mac

  • In Windows, if you can't find python in the folder mentioned in the article, try C:\Users\PC\AppData\Local\Microsoft\WindowsApps -->

• Install Claude Desktop as the MCP Client from their website if you haven't already and login to it

  • If you are using Linux and cannot run any unofficial version of Claude Desktop, you can use any supported MCP Client to test the Gateway. If it does not support mcp cli mcp install command, then go through the scripts code and run the commands supported manually.

• Any other dependencies required for the MCP servers we want to proxy requests to

  • Follow the instructions of the respective MCP server to install its dependencies

  • Like Node.js, npx, docker, etc.

• (Optional) A cache server like KeyDB installed and running (If you want to cache externally and not locally)

Optional Protection with Enkrypt Guardrails

If you want to protect your MCPs with Enkrypt Guardrails, you need to do the following:

• Create a new account if you don't have one. It's free! 🆓 No credit card required 💳🚫

• An ENKRYPT_API_KEY which you can get from Enkrypt Dashboard Settings

• To protect your MCPs with Guardrails, you can use the default sample Guardrail Sample Airline Guardrail to get started or you can create your own custom Guardrail

• To configure custom Guardrails, you need to either login to Enkrypt AI App or use the APIs/SDK

  • Create Guardrails in Enkrypt AI App Dashboard ✅

  • Create Guardrails using APIs

  • Create Guardrails using SDK

  • You can also use Enkrypt MCP Server 🤯 to create Guardrails and use them in the Gateway

Gateway Setup

Check versions

• Check if Python, pip and uv are installed:

# ------------------
# Python
# ------------------

python --version

# Example output
Python 3.13.3

# If not, install python from their website and run the version check again

# ------------------
# pip
# ------------------
pip --version

# Example output
pip 25.0.1 from C:\Users\PC\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.13_qbz5n2kfra8p0\LocalCache\local-packages\Python313\site-packages\pip (python 3.13)

# If not, try the following and run the version check again
python -m ensurepip

# ------------------
# uv
# ------------------

uv --version

# Or run with "python -m" if uv is not found directly
# If this works, use "python -m" before all uv commands from now on
python -m uv --version

# Example output
uv 0.7.9 (13a86a23b 2025-05-30)

# If not, try the following and run the version check again
python -m pip install uv

If any of the above commands fail, please refer the respective documentation to install them properly.

Local Installation

1. Clone the repo, setup virtual environment and install dependencies

• Clone the repository:

cd <your-projects-home>

mkdir enkryptai

cd enkryptai

git clone https://github.com/enkryptai/secure-mcp-gateway

cd secure-mcp-gateway

# Linux/Mac
export ENKRYPT_GATEWAY_HOME=$(pwd)

# Windows
set ENKRYPT_GATEWAY_HOME=%cd%

• Initialize uv project and activate a virtual environment:

# ------------------
# uv
# ------------------

uv init

# Example output
Initialized project `enkrypt-secure-mcp-gateway`

# ------------------
# Create a virtual environment
# ------------------

uv venv

# Example output
Using CPython 3.13.3 interpreter at: C:\Users\PC\AppData\Local\Microsoft\WindowsApps\PythonSoftwareFoundation.Python.3.13_qbz5n2kfra8p0\python.exe
Creating virtual environment at: .venv
Activate with: .venv\Scripts\activate

# ------------------
# Activate the virtual environment
# ------------------

# For Windows, run the following
.\.venv\Scripts\activate

# For Linux/Mac, run the following
source ./.venv/Scripts/activate

# After activating, you should see (enkrypt-secure-mcp-gateway) before the file path in the terminal
# Example:
# (enkrypt-secure-mcp-gateway) C:\Users\PC\Documents\GitHub\enkryptai\secure-mcp-gateway>

# ------------------
# Install pip in the virtual environment
# ------------------

python -m ensurepip

# ------------------
# Install uv in the virtual environment
# ------------------

python -m pip install uv

• Install Python dependencies:

uv pip install -r requirements.txt

• Verify mcp cli got installed successfully:

mcp version

# Example output
MCP version 1.9.2

2. Run the setup script

<!-- - The setup script checks versions of Python, pip, uv and makes sure they are installed and accessible -->

<!-- - It then installs the dependencies -->

• This script creates the enkrypt_mcp_config.json file in the root directory based on the example_enkrypt_mcp_config.json file

• It replaces UNIQUE_GATEWAY_KEY and UNIQUE_UUID with auto generated values and also replaces DUMMY_MCP_FILE_PATH with the actual path to the test MCP file test_mcps/echo_mcp.py

• It also installs the MCP client in Claude Desktop

• NOTE: Please restart Claude Desktop after running the setup script to see the Gateway running in Claude Desktop

# On Linux/Mac run the below
cd $ENKRYPT_GATEWAY_HOME/scripts
chmod +x *.sh
./setup.sh

# On Windows run the below
cd %ENKRYPT_GATEWAY_HOME%\scripts
setup.bat

# Now restart Claude Desktop to see the Gateway running

• Example output:

  -------------------------------
  Setting up Enkrypt Secure MCP Gateway enkrypt_mcp_config.json config file
  -------------------------------
          1 file(s) copied.
  Generated unique gateway key: 3_V8WZxKJp24alEui542WX6wVcgexH5EIBqZl1EssxDcFS9K4TVwZCmB9i_8KEQ5
  Generated unique uuid: b8ac738a-7a2c-4030-8966-20fa1d91af3c
  DUMMY_MCP_FILE_PATH: C:\Users\PC\Documents\GitHub\enkryptai\enkrypt-secure-mcp-gateway\test_mcps\echo_mcp.py
  -------------------------------
  Setup complete. Please check the enkrypt_mcp_config.json file in the root directory and update with your MCP server configs as needed.
  -------------------------------
  -------------------------------
  Installing Enkrypt Secure MCP Gateway with gateway key and dependencies
  -------------------------------
  mcp is installed. Proceeding with installation...
  ENKRYPT_GATEWAY_KEY: 3_V8WZxKJp24alEui542WX6wVcgexH5EIBqZl1EssxDcFS9K4TVwZCmB9i_8KEQ5
  Package names only: flask flask-cors redis requests aiohttp python-json-logger python-dateutil cryptography pyjwt asyncio mcp[cli]
  Dependencies string for the cli install command: --with flask --with flask-cors --with redis --with requests --with aiohttp --with python-json-logger --with python-dateutil --with cryptography --with pyjwt --with asyncio --with mcp[cli]
  Running the cli install command: mcp install gateway.py --env-var ENKRYPT_GATEWAY_KEY=3_V8WZxKJp24alEui542WX6wVcgexH5EIBqZl1EssxDcFS9K4TVwZCmB9i_8KEQ5 --with flask --with flask-cors --with redis --with requests --with aiohttp --with python-json-logger --with python-dateutil --with cryptography --with pyjwt --with asyncio --with mcp[cli]
  Initializing Enkrypt Secure MCP Gateway Common Utilities Module
  Initializing Enkrypt Secure MCP Gateway Module
  --------------------------------
  SYSTEM INFO:
  Using Python interpreter: C:\Users\PC\Documents\GitHub\enkryptai\enkrypt-secure-mcp-gateway\.venv\Scripts\python.exe
  Python version: 3.13.3 (tags/v3.13.3:6280bb5, Apr  8 2025, 14:47:33) [MSC v.1943 64 bit (AMD64)]
  Current working directory: C:\Users\PC\Documents\GitHub\enkryptai\enkrypt-secure-mcp-gateway\src
  PYTHONPATH: Not set
  --------------------------------
  Initializing Enkrypt Secure MCP Gateway Client Module
  Initializing Enkrypt Secure MCP Gateway Guardrail Module
  Getting Enkrypt Common Configuration
  config_path: C:\Users\PC\Documents\GitHub\enkryptai\enkrypt-secure-mcp-gateway\enkrypt_mcp_config.json
  example_config_path: C:\Users\PC\Documents\GitHub\enkryptai\enkrypt-secure-mcp-gateway\example_enkrypt_mcp_config.json
  Loading enkrypt_mcp_config.json file...
  config: {'common_mcp_gateway_config': {'enkrypt_log_level': 'INFO', 'enkrypt_guardrails_enabled': False, 'enkrypt_base_url': 'https://api.enkryptai.com', 'enkrypt_api_key': 'YOUR_ENKRYPT_API_KEY', 'enkrypt_use_remote_mcp_config': False, 'enkrypt_remote_mcp_gateway_name': 'enkrypt-secure-mcp-gateway-1', 'enkrypt_remote_mcp_gateway_version': 'v1', 'enkrypt_mcp_use_external_cache': False, 'enkrypt_cache_host': 'localhost', 'enkrypt_cache_port': 6379, 'enkrypt_cache_db': 0, 'enkrypt_cache_password': None, 'enkrypt_tool_cache_expiration': 4, 'enkrypt_gateway_cache_expiration': 24, 'enkrypt_async_input_guardrails_enabled': False, 'enkrypt_async_output_guardrails_enabled': False}, 'gateways': {'3_V8WZxKJp24alEui542WX6wVcgexH5EIBqZl1EssxDcFS9K4TVwZCmB9i_8KEQ5': {'id': 'b8ac738a-7a2c-4030-8966-20fa1d91af3c', 'mcp_config': [{'server_name': 'echo_server', 'description': 'Dummy Echo Server', 'config': {'command': 'python', 'args': ['C:\\Users\\PC\\Documents\\GitHub\\enkryptai\\enkrypt-secure-mcp-gateway\\test_mcps\\echo_mcp.py']}, 'tools': {'echo': 'Echo a message'}, 'input_guardrails_policy': {'enabled': False, 'policy_name': 'Sample Airline Guardrail', 'additional_config': {'pii_redaction': False}, 'block': ['nsfw', 'toxicity', 'injection_attack']}, 'output_guardrails_policy': {'enabled': False, 'policy_name': 'Sample Airline Guardrail', 'additional_config': {'relevancy': False, 'hallucination': False, 'adherence': False}, 'block': ['nsfw', 'toxicity', 'injection_attack']}}]}}}
  CONFIG:
  ENKRYPT_GATEWAY_KEY: ****KEQ5
  enkrypt_log_level: info
  is_debug_log_level: False
  enkrypt_base_url: https://api.enkryptai.com
  enkrypt_use_remote_mcp_config: False
  enkrypt_api_key: ****_KEY
  enkrypt_tool_cache_expiration: 4
  enkrypt_gateway_cache_expiration: 24
  enkrypt_mcp_use_external_cache: False
  enkrypt_async_input_guardrails_enabled: False
  --------------------------------
  External Cache is not enabled. Using local cache only.
  [06/03/25 20:13:40] INFO     Added server 'Enkrypt Secure MCP Gateway' to Claude config                                                                                                                                                                                    claude.py:143
                      INFO     Successfully installed Enkrypt Secure MCP Gateway in Claude app                                                                                                                                                                                  cli.py:504
  -------------------------------
  Installation complete. Check the claude_desktop_config.json file as per the readme instructions and restart Claude Desktop.
  -------------------------------
  

• To verify, navigate to claude_desktop_config.json file by following these instructions

  • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

  • Windows: %APPDATA%\Claude\claude_desktop_config.json

3. Example MCP config file generated

• Example file in Windows: C:\Users\PC\AppData\Roaming\Claude\claude_desktop_config.json

  {
    "mcpServers": {
      "Enkrypt Secure MCP Gateway": {
        "command": "C:\\Users\\PC\\Documents\\GitHub\\enkryptai\\enkrypt-secure-mcp-gateway\\.venv\\Scripts\\uv.EXE",
        "args": [
          "run",
          "--with",
          "aiohttp",
          "--with",
          "asyncio",
          "--with",
          "cryptography",
          "--with",
          "flask",
          "--with",
          "flask-cors",
          "--with",
          "mcp[cli]",
          "--with",
          "pyjwt",
          "--with",
          "python-dateutil",
          "--with",
          "python-json-logger",
          "--with",
          "redis",
          "--with",
          "requests",
          "mcp",
          "run",
          "C:\\Users\\PC\\Documents\\GitHub\\enkryptai\\enkrypt-secure-mcp-gateway\\src\\gateway.py"
        ],
        "env": {
          "ENKRYPT_GATEWAY_KEY": "3_V8WZxKJp24alEui542WX6wVcgexH5EIBqZl1EssxDcFS9K4TVwZCmB9i_8KEQ5"
        }
      }
    }
  }
  

4. Restart Claude Desktop to run the Gateway

• After restarting, navigate to Claude Desktop Settings

  

• Click on Developer -> Enkrypt Secure MCP Gateway

  

• You can also click on the settings icon below the search bar to see the Gateway in available

  

• Click on Enkrypt Secure MCP Gateway to see the list of tools available

  

• You can check Claude logs while asking Claude to do something to see the Gateway in action

  • Example windows log path: C:\Users\PC\AppData\Roaming\Claude\logs\mcp-server-Enkrypt Secure MCP Gateway.log

  • Example linux/mac log path: ~/Library/Application Support/Claude/logs/mcp-server-Enkrypt Secure MCP Gateway.log

5. Example prompts

• (Accept any requests from Claude by clicking Allow always or Allow once when Cursor asks you to. Allow once is recommended for testing)

  • list all servers, get all tools available and echo test
    • This uses a test MCP server echo_server which is in test_mcps/echo_mcp.py

  

  • We can also combine multiple prompts into one that trigger multiple tool calls at once

  • Example: echo test and also echo best

  

  • Example: echo "hello; ls -la; whoami"

  • This could be a malicious prompt but because no guardrails are enabled, it will not be blocked

  

6. Example config file generated

• Example enkrypt_mcp_config.json generated by the setup script in the root directory:

  {
    "common_mcp_gateway_config": {
      "enkrypt_log_level": "INFO",
      "enkrypt_guardrails_enabled": false,
      "enkrypt_base_url": "https://api.enkryptai.com",
      "enkrypt_api_key": "YOUR_ENKRYPT_API_KEY",
      "enkrypt_use_remote_mcp_config": false,
      "enkrypt_remote_mcp_gateway_name": "enkrypt-secure-mcp-gateway-1",
      "enkrypt_remote_mcp_gateway_version": "v1",
      "enkrypt_mcp_use_external_cache": false,
      "enkrypt_cache_host": "localhost",
      "enkrypt_cache_port": 6379,
      "enkrypt_cache_db": 0,
      "enkrypt_cache_password": null,
      "enkrypt_tool_cache_expiration": 4,
      "enkrypt_gateway_cache_expiration": 24,
      "enkrypt_async_input_guardrails_enabled": false,
      "enkrypt_async_output_guardrails_enabled": false
    },
    "gateways": {
      "tLIYf0YEFTIPLXDO337zPRQhmnoXnLqLUKB3XuDX1inent9vGRFvwLDJGoeaktWu": {
        "id": "2536722c-e5d7-4719-97ab-2cdd4ce942c0",
        "mcp_config": [
          {
            "server_name": "echo_server",
            "description": "Dummy Echo Server",
            "config": {
              "command": "python",
              "args": [
                "C:\\Users\\PC\\Documents\\GitHub\\enkryptai\\enkrypt-secure-mcp-gateway\\test_mcps\\echo_mcp.py"
              ]
            },
            "tools": {},
            "input_guardrails_policy": {
              "enabled": false,
              "policy_name": "Sample Airline Guardrail",
              "additional_config": {
                "pii_redaction": false
              },
              "block": [
                "nsfw",
                "toxicity",
                "injection_attack"
              ]
            },
            "output_guardrails_policy": {
              "enabled": false,
              "policy_name": "Sample Airline Guardrail",
              "additional_config": {
                "relevancy": false,
                "hallucination": false,
                "adherence": false
              },
              "block": [
                "nsfw",
                "toxicity",
                "injection_attack"
              ]
            }
          }
        ]
      }
    }
  }
  

7. Edit the Gateway config as needed

• Important:

  • We need to restart Claude Desktop after editing the config file. To make all new tools accessible, please use prompt "list all servers, get all tools available" for the MCP Client to discover all new tools. After this the MCP Client should be able to use all tools of the servers configured in the Gateway config file

• You can add many MCP servers inside the mcp_config array of this gateway config

  • You can look here for example servers

  • You can also try the Enkrypt MCP Server

  • Example:

    {
      "common_mcp_gateway_config": {...},
      "gateways": { 
        "UNIQUE_GATEWAY_KEY_1": {
          "id": "UNIQUE_UUID_1",
          "mcp_config": [
            {
              "server_name": "MCP_SERVER_NAME_1",
              "description": "MCP_SERVER_DESCRIPTION_1",
              "config": {
                "command": "python/npx/etc.",
                "args": ["arg1", "arg2", ...],
                "env": { "key": "value" }
              },
              // Set explicit tools to restrict access to only the allowed tools
              // Example: "tools": { "tool_name": "tool_description" }
              // Example: "tools": { "echo": "Echo a message" }
              // Or leave the tools empty {} to discover all tools dynamically
              "tools": {},
              "input_guardrails_policy": {...},
              "output_guardrails_policy": {...}
            },
            {
              "server_name": "MCP_SERVER_NAME_2",
              "description": "MCP_SERVER_DESCRIPTION_2",
              "config": {...},
              "tools": {},
              "input_guardrails_policy": {...},
              "output_guardrails_policy": {...}
            }
          ]
        },
      }
    }
    

• If you want a different set of MCP servers for a separate client/user, you can generate a new unqiue key and unique UUID by looking at the setup scripts and add it to the gateways section of the config file

  • Example: { gateways: { UNIQUE_GATEWAY_KEY_1: {...}, UNIQUE_GATEWAY_KEY_2: {...}, ... }, ... }

  • Make sure you also set different UNIQUE_UUID inside the various gateways

• Set enkrypt_log_level to DEBUG to get more detailed logs inside common_mcp_gateway_config part of the config file

  • This defaults to INFO

• Now, inside gateways array, inside mcp_config array, for each individual MCP server config, you can set the following:

  • server_name: A name of the MCP server which we connect to

  • description (optional): A description of the MCP server

  • config: The config for the MCP server as instructed by the MCP server's documentation

    • Generally you have the below keys in the config:

      • command: The command to run the MCP server

      • args: The arguments to pass to the command

      • env: The environment variables to set for the command

  • tools: The tools exposed by the MCP server

    • Either set explicit tools to restrict access to only the allowed tools or leave it empty tools": {} for the Gateway to discover all tools dynamically

    • Tools need to be given a name and a description like "tools": { "dummy_echo": "Echo a message" }

• Skip the below section if you don't want to use Enkrypt Guardrails and move on to Setup Other MCP Clients section

Optional Protection with Enkrypt Guardrails:

• Set enkrypt_guardrails_enabled to true in your common_mcp_gateway_config

• Get your enkrypt_api_key from Enkrypt Dashboard and add it to common_mcp_gateway_config section of the config file

• enkrypt_use_remote_mcp_config is used to fetch MCP server config from Enkrypt server remotely (Coming soon)

  • Please use false for now

  • This enables you to configure and manage MCP gateway config in Enkrypt Dashboard in a centralized place (Coming soon)

• If you have any external cache server like KeyDB running, you can set enkrypt_mcp_use_external_cache to true in your common_mcp_gateway_config

  • Set other relevant keys related to cache in your common_mcp_gateway_config

• enkrypt_tool_cache_expiration (in hours) decides how long the tools discovered from the MCP servers are cached locally or in the external cache server

• enkrypt_gateway_cache_expiration (in hours) decides how long the gateway config is cached locally or in the external cache server. This is useful when we integrate this with Enkrypt Auth server (Coming soon)

• enkrypt_async_input_guardrails_enabled

  • false by default

  • Async mode is not recommended for tools that perform actions which cannot be undone

  • Because the tool call is made parallel to guardrails call, it can't be blocked if input guardrails violations are detected

  • Useful for servers that return just info without performing actions i.e., only read operations

• enkrypt_async_output_guardrails_enabled (Coming soon)

  • This makes output side guardrails calls asynchronously to save time

  • i.e., Guardrails detect call, relevancy check, adherence check, PII unredaction, etc. are made in parallel after getting the response from the MCP server

• Inside each MCP server config, you can set the following:

  • input_guardrails_policy: Use this if we plan to use Enkrypt Guardrails on input side

  • policy_name: Name of the guardrails policy that you have created in the Enkrypt App or using the API/SDK

  • enabled: Whether to enable guardrails on the input side or not. This is false in the example config file

  • additional_config: Additional config for the guardrails policy

    • pii_redaction: Whether to redact PII in the request sent to the MCP server or not

      • If true, this also auto unredacts the PII in the response from the MCP server

  • block: List of guardrails to block

    • Possible values in the array are:

      • topic_detector, nsfw, toxicity, pii, injection_attack, keyword_detector, policy_violation, bias

      • system_prompt_protection, copyright_protection (Coming soon)

      • This is similar to our AI Proxy deployments config. Refer to our docs

• output_guardrails_policy: Use this if we plan to use Enkrypt Guardrails on output side

  • policy_name: Name of the guardrails policy that you have created in the Enkrypt App or using the API/SDK

  • enabled: Whether to enable guardrails on the output side or not. This is false in the example config file

  • additional_config: Additional config for the guardrails policy

    • relevancy: Whether to check for relevancy of the response from the MCP server

    • adherence: Whether to check for adherence of the response from the MCP server

    • hallucination: Whether to check for hallucination in the response from the MCP server (Coming soon)

  • block: List of guardrails to block

    • Possible values in the array are:

      • All possible values in input block array plus adherence, relevancy

      • system_prompt_protection, copyright_protection, hallucination (Coming soon)

      • This is similar to our AI Proxy deployments config. Refer to our docs

• Important:

  • We need to restart Claude Desktop after editing the config file. To make all new tools accessible, please use prompt "list all servers, get all tools available" for the MCP Client to discover all new tools. After this the MCP Client should be able to use all tools of the servers configured in the Gateway config file

Remote Installation

• (Coming soon)

(Optional) Add GitHub MCP Server to the Gateway

• GitHub MCP Server needs docker to be installed. So, please install and have docker running on your machine before proceeding with the steps below

  • You can download docker desktop from here. Install and run it if you don't have it already

• Create a personal access token from GitHub

  • Create a token that has access to only public repos and set expiry very low initially for testing

  • Add the below GitHub server block to enkrypt_mcp_config.json inside "mcp_config": [] array. It should already have the echo server config.

  • NOTE: Don't forget to add comma , after the echo server block

  • Replace REPLACE_WITH_YOUR_PERSONAL_ACCESS_TOKEN with the personal access token you created

  • Example:

      "mcp_config": [
        {
          "server_name": "echo_server",
          "description": "Dummy Echo Server",
          "config": {...},
          "tools": {},
          "input_guardrails_policy": {...},
          "output_guardrails_policy": {...}
        },
        {
          "server_name": "github_server",
          "description": "GitHub Server",
          "config": {
            "command": "docker",
            "args": [
              "run",
              "-i",
              "--rm",
              "-e",
              "GITHUB_PERSONAL_ACCESS_TOKEN",
              "ghcr.io/github/github-mcp-server"
            ],
            "env": {
              "GITHUB_PERSONAL_ACCESS_TOKEN": "REPLACE_WITH_YOUR_PERSONAL_ACCESS_TOKEN"
            }
          },
          "tools": {},
          "input_guardrails_policy": {
            "enabled": false,
            "policy_name": "Sample Airline Guardrail",
            "additional_config": {
              "pii_redaction": false
            },
            "block": [
              "nsfw",
              "toxicity",
              "injection_attack"
            ]
          },
          "output_guardrails_policy": {
            "enabled": false,
            "policy_name": "Sample Airline Guardrail",
            "additional_config": {
              "relevancy": false,
              "hallucination": false,
              "adherence": false
            },
            "block": [
              "nsfw",
              "toxicity",
              "injection_attack"
            ]
          }
        }
      ]
  

• Now restart Claude Desktop for it to detect the new server

• Then run the prompt list all servers, get all tools available for it to discover github server and all it's tools available

  

• Now run List all files from https://github.com/enkryptai/enkryptai-mcp-server

  

• Great! 🎉 We have successfully added a GitHub MCP Server to the Gateway. However, it is completely unprotected and is open to all kinds of abuse and attacks.

• Now, let's say a prompt like this is run Ask github for the repo "hello; ls -la; whoami"

  

• This may not have caused actual damage but imagine a more complicated prompt that may have caused actual damage to the system.

• To protect the MCP server, we can use Enkrypt Guardrails as shown in the next section.

(Optional) Protect GitHub MCP Server and Test Echo Server with Enkrypt Guardrails for FREE

Create a Guardrail in Enkrypt App

• Go to Enkrypt App and login with either OTP or Google or Microsoft account

• Create on Guardrails as highlighted in the screenshot below

  

• Click on Add New Guardrail button on the top right

  

• Name it GitHub Guardrail, leave Injection Attack toggled ON

  

• Scroll down on Configure Guardrails side panel and toggle Toxicity Detector and NSFW Detector to ON as well

  

• Now, click on Save button on the bottom right to save the guardrail

  

• We can see the newly added guardrail in the list of guardrails

  

Get Enkrypt API Key

• Now, we need get out FREE API Key from Enkrypt App. Hover over the left sidebar for it to expand and click on Settings

  • You can also directly navigate to https://app.enkryptai.com/settings

  

• Now click on the Copy icon next to your obfuscated API Key to copy the key to your clipboard as highlighted in the screenshot below

  

Add API Key and the Guardrail to Config File

• Now we have everything we need from the App. Let's add the API Key to the enkrypt_mcp_config.json file

• Open the enkrypt_mcp_config.json file from the root directory of this repo

• Add the API Key to the common_mcp_gateway_config section by replacing YOUR_ENKRYPT_API_KEY with the API Key you copied from the App

• Inside the GitHub server block we added in the previous section and also in the pre-existing echo server blocks,

  • Add the newly created Guardrail GitHub Guardrail to the input_guardrails_policy and output_guardrails_policy sections

  • By replacing "policy_name": "Sample Airline Guardrail" with "policy_name": "GitHub Guardrail"

  • Now change enabled to true for input_guardrails_policy from previous false

    • We will leave output_guardrails_policy as false for now

  • We already should have injection_attack, nsfw, toxicity in the block array for both policies

  • So the final config should look something like this:

  {
    "common_mcp_gateway_config": {
      ...
      "enkrypt_api_key": "xxxxxxxxxxxxxxxxxxxxxxxxxxxx",
      ...
    },
    "gateways": {
      "tLIYf0YEFTIPLXDO337zPRQhmnoXnLqLUKB3XuDX1inent9vGRFvwLDJGoeaktWu": {
        "id": "2536722c-e5d7-4719-97ab-2cdd4ce942c0",
        "mcp_config": [
          {
            "server_name": "echo_server",
            "description": "Dummy Echo Server",
            "config": {
              "command": "python",
              "args": [
                "C:\\Users\\PC\\Documents\\GitHub\\enkryptai\\enkrypt-secure-mcp-gateway\\test_mcps\\echo_mcp.py"
              ]
            },
            "tools": {},
            "input_guardrails_policy": {
              "enabled": true,
              "policy_name": "GitHub Guardrail",
              "additional_config": {
                "pii_redaction": false
              },
              "block": [
                "nsfw",
                "toxicity",
                "injection_attack"
              ]
            },
            "output_guardrails_policy": {
              "enabled": false,
              "policy_name": "GitHub Guardrail",
              "additional_config": {
                "relevancy": false,
                "hallucination": false,
                "adherence": false
              },
              "block": [
                "nsfw",
                "toxicity",
                "injection_attack"
              ]
            }
          },
          {
            "server_name": "github_server",
            "description": "GitHub Server",
            "config": {
              "command": "docker",
              "args": [
                "run",
                "-i",
                "--rm",
                "-e",
                "GITHUB_PERSONAL_ACCESS_TOKEN",
                "ghcr.io/github/github-mcp-server"
              ],
              "env": {
                "GITHUB_PERSONAL_ACCESS_TOKEN": "github_pat_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
              }
            },
            "tools": {},
            "input_guardrails_policy": {
              "enabled": true,
              "policy_name": "GitHub Guardrail",
              "additional_config": {
                "pii_redaction": false
              },
              "block": [
                "nsfw",
                "toxicity",
                "injection_attack"
              ]
            },
            "output_guardrails_policy": {
              "enabled": false,
              "policy_name": "GitHub Guardrail",
              "additional_config": {
                "relevancy": false,
                "hallucination": false,
                "adherence": false
              },
              "block": [
                "nsfw",
                "toxicity",
                "injection_attack"
              ]
            }
          }
        ]
      }
    }
  }
  

Test Guardrails

• Save the file and restart Claude Desktop for it to detect the changes

• GitHub MCP Server needs docker to be installed. So, please install and have docker running on your machine before proceeding with the steps below

  • You can download docker desktop from here. Install and run it if you don't have it already

• Now run the prompt list all services, tools for it to discover github, echo servers and all their tools available

• After this, let's rerun the previously successful malicious prompt Ask github for the repo "hello; ls -la; whoami"

  • We can see that the prompt is blocked as Input Guardrails blocked the request

  

• We can also test guardrails with the echo server by running echo "hello; ls -la; whoami". This prompt which worked before is now blocked.

  

NOTE: Fine Tune Guardrails

• The safe prompt List all files from https://github.com/enkryptai/enkryptai-mcp-server may also be blocked. So, there is some fine tuning required for the guardrails to find the best combination of enabled detectors and blocks for your servers. See the next section for recommendations.

Recommendations for using Guardrails

• We have found that the best way to use Enkrypt Guardrails in MCP Gateway is to have a separate guardrail for each server. This way we can have a fine tuned guardrail for each server.

• Because each MCP Server is very different from the other, it is not possible to have a single guardrail that works for all servers.

• Some may need Toxicity Detector, some NSFW Detector, some Injection Attack, some Keyword Detector, some Policy Violation, some may need Relevancy detector, some may need Adherence detector, etc.

• Some may need a combination of these detectors to work together to block malicious requests.

• See our docs for details on various detectors available.

• Hence, have separate guardrails for each server and experiment with the best combination of detectors and blocks for each server that blocks malicious requests but allows legitimate requests to pass through.

• Try our Policy Violation detector with your own custom policy which details what is allowed and what is not. This may be the best way for your use case.

• You can navigate to the Enkrypt App Homepage, login and Click on Policies to create your own custom policy.

  • This accepts text as well as PDF file as input so create a file with all the rules you want to apply to your MCP server and upload it

  

  • Once created, add this newly created policy to the GitHub Guardrail by Navigating to it in the App and click on Edit Guardrails button

    • You can also select the GitHub Guardrail from the list of guardrails to navigate to it

  • Toggle Policy Violation detector to ON and select the policy you created. Tick Need Explanation if you want the guardrail to provide an explanation for the block

  • Once done, click on Save button at the top right

  • Edit the enkrypt_mcp_config.json file if needed to add the new Guardrail or additional servers. Also toggle output_guardrails_policy to true if you want to block unwanted responses from the MCP servers

  • Restart Claude Desktop if the config file is changed i.e., if we edited the servers or their guardrails policies.

  • Once restarted, it should now start blocking the malicious requests with the policy you created.

Setup Other MCP Clients

Cursor

• You can navigate to cursor's Global MCP file at C:\Users\PC\.cursor\mcp.json on Windows or at ~/.cursor/mcp.json on Linux/macOS

  • If you would like to use at a Project level place it inside your project. For details see Cursor's docs

• You can also navigate to the file Via cursor's UI by clicking on settings gear icon on the top right

  

• Click on MCP and then click on Add new global MCP server which takes you to the mcp.json file

  

• Example mcp.json file opened in the editor

  

• Once the file is opened at Global or Project level, you can copy paste the same config we used in Claude Desktop. For reference, you can refer to Installation - 3. Example MCP config file generated 📄

  • Be sure to use your own file that was generated by the setup script in Installation - 2. Run the setup script 📥. Please do not copy paste the example config file in this repo.

• Once your mcp config is pasted and the file is saved, you can see the MCP server in the list of MCP servers in cursor

  

• Now you can chat with the MCP server.

  • Example prompts:

    • (Click Run Tool when Cursor asks you to)

    • list all servers, get all tools available and echo test

      • This uses a test MCP server echo_server which is in test_mcps/echo_mcp.py

    

Other Tools Available

Get Cache Status

• The Gateway can give the summary of it's cache status by looking at the local/external cache server

• This is useful to debug issues if for example a tool was updated remotely by a server but the Gateway is not aware of it yet

  

Clear Cache

• The Gateway can clear it's cache from local/external cache server

• This is useful to clear the cache if for example a tool was updated remotely by a server but the Gateway is not aware of it yet

• You can either clear all cache or specific cache by providing the server_name

  • Example: clear cache for echo_server

• You can also clear all cache or just the gateway cache or just the server cache

  • Example: clear all cache, clear just gateway cache, clear server cache for echo_server, Clear all server cache

  

Deployment patterns

1. Local Gateway, Local Guardrails and Local MCP Server
2. Local Gateway, Local MCP Server with Remote Guardrails
3. Local Gateway with Remote MCP Server and Remote Guardrails
4. Remote Gateway, Remote MCP Server and Remote Guardrails

1. Local Gateway, Local Guardrails and Local MCP Server

2. Local Gateway, Local MCP Server with Remote Guardrails

3. Local Gateway with Remote MCP Server and Remote Guardrails

4. Remote Gateway, Remote MCP Server and Remote Guardrails

Known Issues being worked on

• Output guardrails are not being applied to non-text tool results. Support for other media types like images, audio, etc. is coming soon.

Known Limitations

• The Gateway does not support a scenario where the Gateway is deployed remotely but the MCP server is deployed locally (without being exposed to the internet). This is because the Gateway needs to know the MCP server's address to forward requests to it.

License

Enkrypt AI MCP Gateway Core

This project's core functionality is licensed under the MIT License.

<!-- In addition to the MIT License, the following additional terms apply:

• You can freely use, modify, and distribute this software as part of your commercial product
• You can use this as part of your commercial product if your product is not an MCP gateway or gateway-based service
• You cannot sell this gateway as a standalone product -->

For the full license text, see the LICENSE.txt file in this repository.

Enkrypt AI Guardrails, Logo, and Branding

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Enkrypt AI software is provided under a proprietary license. Unauthorized use, reproduction, or distribution of this software or any portion of it is strictly prohibited.

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Enkrypt AI and the Enkrypt AI logo are trademarks of Enkrypt AI, Inc.

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