McpAuth is the authentication and authorization component of the MCP Gateway Proof of Concept (PoC) described in the paper:
Simplified and Secure MCP Gateways for Enterprise AI Integration
Ivo Brett, CISSP, B.Eng, MSc
View Paper (2025)
This repository is part of a broader initiative to enable secure, scalable, and compliant enterprise integration with the Model Context Protocol (MCP). See the website SelfHostedMCP.com. It provides an extensible OAuth2.1-based authentication gateway that offloads identity, authorization, and policy management from backend MCP servers—ensuring conformance with the 2025-03-26 MCP Specification.
McpAuth is designed to:
- Decouple security logic from MCP servers
- Centralize identity management using OAuth 2.1 & OIDC
- Support dynamic client registration
- Enforce fine-grained token scopes and policy controls
- Act as a composable module in enterprise-grade Zero Trust architectures
This implementation is part of a larger PoC that validates:
- A reference MCP Gateway architecture for secure deployments
- Threat model mapping aligned with frameworks such as MAESTRO and Narajala & Habler
- Real-world compatibility with tools like Cloudflare Tunnels, WireGuard, Traefik, and CrowdSec
The full proof of concept includes:
- Two isolated MCP servers (local and cloud-based)
- Secure tunneling via WireGuard and Pangolin
- Centralized intrusion detection and observability
- Seamless integration with Anthropic's MCP Inspector
- 🔐 OAuth2 authentication with PKCE via Traefik
forwardAuth - ⚡ Seamless integration with MCP Gateway SSE endpoints
- ✅ Email whitelisting for controlled access
- 🐳 Docker-ready, easy to deploy
- 🧪 Includes a Python-based test server
Go to the Google Cloud Console Navigate to APIs & Services > Credentials Click Create Credentials → OAuth client ID Choose Web Application Add an Authorized redirect URI — you’ll get this later when you set up Traefik, but it will look like: https://oauth.yourdomain.com/callback
Save the Client ID and Client Secret for later use.
CLIENT_ID=<INSERT_VALUE_FROM_GOOGLE>
CLIENT_SECRET=<INSERT_VALUE_FROM_GOOGLE>
Use flags or environment variables:
| Variable | Default | Description |
|---|---|---|
PORT |
11000 |
Port for the auth server |
PROTECTED_PATH |
/sse |
Protected endpoint path |
OAUTH_DOMAIN |
(none) | OAuth issuer domain |
CLIENT_ID |
(none) | OAuth client ID |
CLIENT_SECRET |
(none) | OAuth client secret |
ALLOWED_EMAILS |
(none) | Comma-separated list of allowed emails |
LOG_LEVEL |
1 |
0=debug, 1=info, 2=minimal |
services:
mcpauth:
image: oideibrett/mcpauth:latest
environment:
- PORT=11000
- CLIENT_ID=${CLIENT_ID}
- CLIENT_SECRET=${CLIENT_SECRET}
ports:
- "11000:11000"
traefik:
image: traefik::v3.4.1
command:
- "--providers.docker=true"
- "--entrypoints.websecure.address=:443"
ports:
- "443:443"
volumes:
- /var/run/docker.sock:/var/run/docker.sock- Go 1.21+
- Traefik v2.x+
- An OAuth provider (e.g., Google, GitHub)
git clone https://github.com/oidebrett/mcpauth
cd mcpauth
go mod tidygo run cmd/main.go -port=11000 -oauthDomain=your-domain.comservices:
mcpauth:
build: .
environment:
- PORT=11000
- CLIENT_ID=${CLIENT_ID}
- CLIENT_SECRET=${CLIENT_SECRET}
ports:
- "11000:11000"http:
middlewares:
mcp-auth:
forwardAuth:
address: "http://mcpauth:11000/sse"
authResponseHeaders:
- "X-Forwarded-User"labels:
- "traefik.http.routers.myapp.middlewares=mcp-auth@file"cd test_mcp_server
python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt
python mcp-server-sse.pycurl -i http://localhost:11000/health
curl -i http://localhost:11000/sseApply middlewares in this order:
mcp-cors-headersredirect-regexmcp-auth
Example dynamic config:
http:
middlewares:
mcp-cors-headers:
headers:
accessControlAllowCredentials: true
accessControlAllowHeaders:
- Authorization
- Content-Type
- mcp-protocol-version
accessControlAllowMethods:
- GET
- POST
- OPTIONS
accessControlAllowOriginList:
- "*"
accessControlMaxAge: 86400
addVaryHeader: true
redirect-regex:
redirectRegex:
regex: "^https://([a-z0-9-]+)\\.(.+)/\\.well-known/(.+)"
replacement: "https://oauth.${2}/.well-known/${3}"
permanent: true
mcp-auth:
forwardAuth:
address: "http://mcpauth:11000/sse"
authResponseHeaders:
- X-Forwarded-UserThis project supports middleware-manager.
Example templates.yml:
middlewares:
- id: mcp-auth
name: MCP Authentication
type: forwardAuth
config:
address: "http://mcpauth:11000/sse"
authResponseHeaders:
- "X-Forwarded-User"
- id: mcp-cors-headers
name: MCP CORS Headers
type: headers
config:
accessControlAllowMethods:
- GET
- POST
- OPTIONS
accessControlAllowOriginList:
- "*"
accessControlAllowHeaders:
- Authorization
- Content-Type
- mcp-protocol-version
accessControlMaxAge: 86400
accessControlAllowCredentials: true
addVaryHeader: true
- id: redirect-regex
name: Regex Redirect
type: redirectregex
config:
regex: "^https://([a-z0-9-]+)\\.yourdomain\\.com/\\.well-known/oauth-authorization-server"
replacement: "https://oauth.yourdomain.com/.well-known/oauth-authorization-server"
permanent: trueLicensed under the GNU General Public License v3.0.