Rohlik MCP Proxy

A proxy server that connects Claude (iOS, Android, Web, Desktop) to Rohlik's MCP server.

Rohlik's MCP server requires custom rhl-email/rhl-pass headers that Claude can't set directly. This proxy bridges that gap — users sign in once via OAuth 2.1 and Claude handles the rest.

Claude  →  POST /mcp (Bearer token)  →  Proxy  →  POST mcp.rohlik.cz/mcp (rhl-email/rhl-pass)  →  Rohlik

Requirements

• Bun v1.0+

Setup

# Clone and install
git clone <repo-url>
cd rohlik-mcp-proxy
bun install

# Configure
cp .env.example .env
# Edit .env with your values

Environment variables

Variable	Required	Description
PROXY_SECRET	Yes	Encryption key for stored credentials (min 32 chars)
PORT	No	Server port (default: 3000)
PUBLIC_URL	No	Public-facing URL (default: http://localhost:3000)
ROHLIK_MCP_URL	No	Rohlik MCP endpoint (default: https://mcp.rohlik.cz/mcp)
OPERATOR_NAME	No	Displayed on the landing page as the server operator
OPERATOR_EMAIL	No	Contact email displayed on the landing page

Running

# Production
bun run start

# Development (auto-reload)
bun run dev

# Manage accounts
bun run cli list              # List all registered users
bun run cli delete <id>       # Delete a user by ID

How it works

1. User adds <PUBLIC_URL>/mcp as a remote MCP server in Claude.
2. Claude initiates OAuth 2.1 (Authorization Code + PKCE):
   • Registers a client via /oauth/register
   • Opens the authorize page where the user enters Rohlik credentials
   • Exchanges the auth code for a Bearer token via /oauth/token
3. Claude sends MCP requests to /mcp with the Bearer token.
4. The proxy decrypts the stored Rohlik credentials and forwards requests to Rohlik's MCP server with the required headers.

Security

• Credentials encrypted at rest — AES-256-GCM using PROXY_SECRET
• Tokens hashed — SHA-256, never stored in plaintext
• OAuth 2.1 with PKCE — S256 code challenge, one-time auth codes (10 min expiry)
• CSRF protection — one-time tokens on the authorize form
• Rate limiting — per-IP on OAuth endpoints (20/min), per-token on MCP (60/min), per-IP on unauthenticated requests (30/min)
• Request size limit — 1MB max body
• Security headers — CSP, HSTS, X-Frame-Options, X-Content-Type-Options
• SQLite DB — file permissions restricted to owner (600)

Warning: Rohlik credentials (email + password) are stored encrypted on the server. They must be stored because Rohlik's MCP server requires them on every request. Only deploy this on infrastructure you control and trust.

Project structure

src/
├── index.ts          # HTTP server, routing
├── oauth.ts          # OAuth 2.1 flow (metadata, registration, authorize, token)
├── proxy.ts          # MCP message forwarding to Rohlik
├── auth.ts           # Bearer token resolution
├── store.ts          # SQLite DB, encryption, user/client/code storage
├── security.ts       # Rate limiting, input validation, security headers
├── log.ts            # Structured console logging
├── cli.ts            # CLI tool for account management
├── landing.html      # Public landing page
└── authorize.html    # OAuth sign-in form

API endpoints

Method	Path	Auth	Description
GET	/	—	Landing page
GET	/.well-known/oauth-authorization-server	—	OAuth metadata
POST	/oauth/register	—	Dynamic client registration
GET	/oauth/authorize	—	Authorize page (login form)
POST	/oauth/authorize	—	Submit credentials, get auth code
POST	/oauth/token	Client	Exchange auth code for access token
POST	/mcp	Bearer	Forward MCP request to Rohlik
GET	/mcp	Bearer	SSE stream from Rohlik
DELETE	/mcp	Bearer	Close MCP session

Author

Vaclav Slajs — vaclav@slajs.eu

License

MIT