MCP-S Gateway

mcp-gateway is a secure gateway and integration layer for the Model Context Protocol (MCP). It provides a unified, enterprise-ready interface for connecting, managing, and extending MCP modules and services, with a focus on security and seamless integration.

Quick Start

1. Configure your MCP servers - Create mcp.json file in your project:

{
  "mcpServers": {
    "your-server": {
      "command": "npx",
      "args": ["-y", "@your-mcp-server"],
      "env": {
        "API_KEY": "your-api-key"
      }
    }
  }
}

2. Add your .env file using this example:

AUTH_SECRET=E/MAdDq0B1aX+MGNyVlEUk0WzRpCdimlCrUOKST1CxKH # Generate with command: openssl rand -base64 33
AUTH_PROVIDER=google
AUTH_GOOGLE_ID=...apps.googleusercontent.com
AUTH_GOOGLE_SECRET=GOCSPX-...

See Advanced Configuration for more.

3. Start with npx (Recommended):

# Default (uses ./mcp.json and ./.env)
npx @mcp-s/secure-mcp-gateway

# Custom configuration paths
npx @mcp-s/secure-mcp-gateway --mcp-config ./custom/mcp.json --envfile ./custom/.env

Or clone:

git clone https://github.com/mcp-s-ai/secure-mcp-gateway.git
cd secure-mcp-gateway
npm install && npm run start

4. Add to your MCP configuration:

For Cursor/Claude Desktop/VS Code - Add this to your MCP settings:

STDIO Configuration:

{
  "mcpServers": {
    "mcp-gateway": {
      "command": "npx",
      "args": ["-y", "@mcp-s/mcp"],
      "env": {
        "BASE_URL": "http://localhost:3000"
      }
    }
  }
}

StreamableHTTP Configuration:

{
  "mcpServers": {
    "mcp-gateway": {
      "url": "http://localhost:3000/mcp"
    }
  }
}

Features

• Self-Hosted Gateway: Deploy within your own infrastructure for maximum control
• OAuth Authentication: Secure authentication with any OAuth provider via Auth.js
• TypeScript Support: Fully typed for robust development

Supports all MCP Connection Types:

• STDIO: Standard input/output MCP servers

• StreamableHTTP: HTTP-based streaming connections via http://localhost:3000/mcp (or https://<your-domain>/mcp for hosted deployments)

  Server Selection: You can connect to a specific MCP server by adding the ?server_name=XXX query parameter, where XXX is the name of the server from your mcp.json configuration. For example: http://localhost:3000/mcp?server_name=your-server

  Connect with your preferred AI client:

  | Client | Link | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------- | | Claude | claude.ai | | Cursor | cursor.com | | Windsurf | codeium.com/windsurf | | VSCode | code.visualstudio.com | | Cline | cline.tools | | Highlight AI | highlightai.com | | Augment Code | augmentcode.com |

Deploy

Deploy the mcp-s gateway using npx:

1. Set up your environment variables (see Advanced Configuration)
2. Create your mcp.json configuration file
3. Run npx @mcp-s/secure-mcp-gateway

For production deployments, consider using:

• Process managers like PM2: pm2 start "npx @mcp-s/secure-mcp-gateway" --name mcp-gateway
• Container orchestration (Docker, Kubernetes)
• Cloud platforms (Heroku, Railway, Render)

Authentication Setup

mcp-gateway leverages the power of Auth.js, which supports 80+ OAuth providers out of the box. This makes Auth.js the perfect companion for an open-source project like mcp-gateway. Both libraries share the same commitment to flexibility, security, and developer experience. By integrating with Auth.js, we avoid reinventing authentication wheels and instead provide you with battle-tested, production-ready OAuth flows that work seamlessly across providers.

Simply set the AUTH_PROVIDER environment variable and provide the required credentials for your chosen provider - mcp-gateway handles the rest.

Documentation: Auth.js Google Provider

AUTH_SECRET=your-random-secret
AUTH_PROVIDER=google
AUTH_GOOGLE_ID=your-google-client-id
AUTH_GOOGLE_SECRET=your-google-client-secret

Documentation: Auth.js Okta Provider

AUTH_SECRET=your-random-secret
AUTH_PROVIDER=okta
AUTH_OKTA_ID=your-okta-client-id
AUTH_OKTA_SECRET=your-okta-client-secret
AUTH_OKTA_ISSUER=https://your-okta-domain.okta.com/oauth2/default

Documentation: Auth.js Azure AD Provider

AUTH_SECRET=your-random-secret
AUTH_PROVIDER=azure-ad
AUTH_AZURE_AD_ID=your-azure-client-id
AUTH_AZURE_AD_SECRET=your-azure-client-secret
AUTH_AZURE_AD_TENANT_ID=your-tenant-id-or-common

For other providers, see the Auth.js Providers documentation.

Advanced Configuration

Command Line Options

| Option | Description | Default Value | Example | | -------------- | -------------------------------------- | ------------- | ------------------------------------ | | --mcp-config | Path to MCP servers configuration file | ./mcp.json | --mcp-config ./config/servers.json | | --envfile | Path to environment variables file | ./.env | --envfile ./config/production.env |

Environment Variables

| Environment Variable | Description | Default Value | Required | | ------------------------ | ------------------------------------------------------------------------------------------------------------------ | ----------------------- | -------- | | PORT | Server port | 3000 | No | | BASE_URL | Base URL for the gateway | http://localhost:3000 | No | | AUTH_SECRET | Secret for signing/encrypting tokens (generate with openssl rand -base64 33) | - | Yes | | AUTH_PROVIDER | OAuth provider name | google | No | | TOKEN_EXPIRATION_TIME | Token expiration time in milliseconds | 86400000 (24h) | No | | DB_PATH | SQLite database file path | ./mcp.sqlite | No | | AUTH_[Provider]_ID | OAuth client ID for your provider | - | Yes | | AUTH_[Provider]_SECRET | OAuth client secret for your provider | - | Yes | | AUTH_[Provider]_* | Additional provider-specific variables (see Auth.js documentation) | - | Varies |

Troubleshooting

Issue: When using StreamableHTTP configuration in Cursor, tools don't appear even after successful authentication.

Solution: Make sure you have only one Cursor window open. Multiple Cursor windows can interfere with the MCP connection establishment.

1. Close all Cursor windows
2. Open a single Cursor window
3. Retry the authentication process

Issue: You see the following error:

Error [ERR_UNKNOWN_BUILTIN_MODULE]: No such built-in module: node:sqlite

Solution: This error occurs when using an older version of Node.js. The node:sqlite module requires Node.js version 22 or higher.

Fix:

1. Update Node.js to version 22 or later
2. Verify your version: node --version
3. Restart the gateway: npm run start

Installation options:

• Using nvm: nvm install 22 && nvm use 22
• Download from nodejs.org

Hosted Solution

Visit mcp-s.com for our fully managed hosting solution with advanced features:

• Zero Configuration: Get started in seconds without any setup
• Enterprise-grade Security: Advanced SSO authentication for all MCP interactions
• 20+ Pre-built Connectors: Fast plug-and-play integration with hundreds of tools
• Roles & Permissions: Granular access control with custom role definitions
• Monitoring & Analytics: Real-time insights into your MCP usage
• High Availability: 99.9% uptime SLA with global CDN
• Premium Support: Direct access to our engineering team
• Custom Integrations: Build and deploy custom MCP connectors

Community

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License

Released under the MIT License. Contributions welcome - star & fork!