mendix-claude-proxy

A lightweight TypeScript/Express proxy server that forwards requests from a Mendix Studio Pro extension to the Anthropic Claude API. Keeps your API key secure on the server rather than inside the extension.

How it works

Mendix Extension → POST /ask-claude → This Server → Anthropic API
                ← { reply: "..." } ←              ←

Endpoints

Method	Path	Description
GET	/health	Health check — returns { status: "ok" }
POST	/ask-claude	Send messages to Claude, get a reply

POST /ask-claude

Request body:

{
  "messages": [
    { "role": "user", "content": "Hello!" }
  ],
  "system": "Optional system prompt",
  "max_tokens": 1024
}

Response:

{
  "reply": "Hello! How can I help you?",
  "input_tokens": 10,
  "output_tokens": 12
}

---

Running locally

Prerequisites

• Node.js 20+
• An Anthropic API key from console.anthropic.com

Setup

# 1. Install dependencies
npm install

# 2. Create your .env file
cp .env.example .env
# Then edit .env and add your ANTHROPIC_API_KEY

# 3. Start in dev mode (auto-restarts on changes)
npm run dev

The server will be available at http://localhost:3000.

---

Running with Docker

# 1. Create your .env file
cp .env.example .env
# Edit .env and add your ANTHROPIC_API_KEY

# 2. Build and start
docker compose up --build

# 3. Run in background
docker compose up -d --build

---

Deploying to Portainer

1. Push this repo to GitHub
2. In Portainer, go to Stacks → Add stack
3. Choose Repository and point it at your GitHub repo
4. Under Environment variables, add ANTHROPIC_API_KEY with your key
5. Deploy

To expose the server externally, set up a Cloudflare Tunnel pointing at localhost:3000.

---

Calling from your Mendix extension

const response = await fetch("https://your-server-url/ask-claude", {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify({
        messages: [{ role: "user", content: userInput }]
    })
});

const { reply } = await response.json();

---

Environment variables

Variable	Required	Default	Description
ANTHROPIC_API_KEY	✅	—	Your Anthropic API key
PORT	❌	3000	Port the server listens on
ALLOWED_ORIGIN	❌	*	CORS origin — restrict in production