PC Express MCP Server

Unofficial Model Context Protocol (MCP) server for PC Express / Loblaws grocery shopping

Control your grocery cart with AI! This MCP server enables LLMs (like Claude) to search past orders, find products, and manage your shopping cart across all Loblaws-owned grocery banners.

How the auth was cracked: the login sits behind Akamai bot detection, so the OAuth flow was reverse-engineered out of Loblaw's Android app. If you want the emulator-and-mitmproxy story behind pcid_config.py, read the write-up: Reverse-engineering PC Express.

⚠️ Important Disclaimers

• Unofficial: This project is NOT affiliated with, endorsed by, or supported by Loblaws Companies Limited, PC Express, or any related entities

• Use at Your Own Risk: This uses an undocumented API that may change without notice

• No Warranty: See LICENSE for details

• Educational Purpose: This project demonstrates API reverse engineering and MCP server development

Related MCP server: Willys MCP Server

🛒 Supported Grocery Banners

Works with all PC Express enabled stores:

• Zehrs - Ontario-based grocery chain

• Loblaws - Main flagship banner

• No Frills - Discount grocery banner

• Real Canadian Superstore - Western Canada supermarket

• Your Independent Grocer - Franchise stores

• T&T Supermarket - Asian specialty supermarket

✨ Features

MCP Tools (6)

1. search_past_orders - Find items from your order history

2. get_order_items - Get detailed product list from specific orders

3. search_products - Search the product catalog

4. add_to_cart - Add products to your shopping cart

5. remove_from_cart - Remove items from cart

6. view_cart - See current cart contents

Integration Ready

• ✅ Home Assistant - Voice-controlled grocery shopping

• ✅ Claude Desktop - Chat with your grocery list

• ✅ Custom Clients - Any MCP-compatible application

Voice Assistant Examples

🎤 "Add ice cream to my grocery cart"
🎤 "What did I order last week?"
🎤 "Search for organic bananas"
🎤 "What's in my cart?"

🚀 Quick Start

Prerequisites

• Python 3.10 or higher

• Active account with a PC Express enabled banner

• pip or pip3

Installation

1. Clone the repository

   git clone https://github.com/YOUR_USERNAME/pcexpress-mcp-server.git
   cd pcexpress-mcp-server

2. Install dependencies

   pip install -r requirements.txt

3. Configure credentials

   cp .env.example .env
   # Edit .env with your credentials (see Configuration section)

4. Test the connection

   python test_api.py

5. Run the server

   python pcexpress_mcp_server.py

⚙️ Configuration

Getting Your Credentials

Authentication uses the PC Express app's OAuth flow. You sign in once in a real browser to get a refresh token; after that the server mints access tokens on its own and never needs another manual login. See AUTH_NOTES.md for how it works, and DEPLOYMENT.md for running it locally, in Docker, Home Assistant, or Kubernetes.

Easiest: run the setup wizard; it logs you in and writes the config for wherever you run it:

python setup.py

The manual steps below are the same thing, done by hand.

One-time login

python login_pcid.py

It opens your browser to the PC ID sign-in. After you log in, the page tries to open a com.loblaw.pcx://... link and shows an error; that is expected. Copy that full address from the address bar and paste it back into the script. It prints your PCEXPRESS_REFRESH_TOKEN. The app client secret is baked into the code, so you don't supply it.

Automated login (optional, no paste)

If you'd rather not paste anything, login_pcid_auto.py drives a browser for you:

pip install -r requirements-auto.txt && python -m playwright install chromium
PCEXPRESS_CLIENT_SECRET=... PCEXPRESS_EMAIL=you@example.com PCEXPRESS_PASSWORD=... \
    python login_pcid_auto.py

It logs in and prints the same two values. It runs a headed browser (Akamai blocks headless), so run it on a machine with a display, or under xvfb-run on a headless box. Accounts with 2FA can't be automated; use the manual login_pcid.py for those. Either way, the browser is used only for this one-time step; the server never runs a browser.

Your cart id and customer id are read from your profile at runtime, so you don't set them.

Environment Variables

# Refresh token from the one-time login above (server rotates/persists it after first use)
PCEXPRESS_REFRESH_TOKEN=your_refresh_token_here

# Writable dir for the rotated token + cached access token; must persist across restarts
PCEXPRESS_STATE_DIR=~/.pcexpress-mcp

# Banner: zehrs, loblaws, nofrills, superstore, independent, tandt
PCEXPRESS_BANNER=zehrs

# Store ID (4-digit code)
PCEXPRESS_STORE_ID=your_store_id_here

# Optional: cart id is auto-discovered; set only to force a specific cart.
# PCEXPRESS_CART_ID=your_cart_id_here
# Optional: the app client secret is baked in; set only to override it.
# PCEXPRESS_CLIENT_SECRET=your_client_secret_here

🔌 Platform Integration

Home Assistant

# configuration.yaml
mcp:
  servers:
    - name: pcexpress
      command: python3
      args:
        - /path/to/pcexpress_mcp_server.py
      env:
        PCEXPRESS_REFRESH_TOKEN: "your_refresh_token"
        PCEXPRESS_STATE_DIR: "/config/pcexpress-mcp"
        PCEXPRESS_STORE_ID: "your_store"
        PCEXPRESS_BANNER: "zehrs"

Claude Desktop

Edit your Claude Desktop config:

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

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

{
  "mcpServers": {
    "pcexpress": {
      "command": "python3",
      "args": ["/path/to/pcexpress_mcp_server.py"],
      "env": {
        "PCEXPRESS_REFRESH_TOKEN": "your_refresh_token",
        "PCEXPRESS_STATE_DIR": "~/.pcexpress-mcp",
        "PCEXPRESS_STORE_ID": "your_store",
        "PCEXPRESS_BANNER": "zehrs"
      }
    }
  }
}

Restart Claude Desktop and start chatting about groceries!

Custom MCP Client

from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client

server_params = StdioServerParameters(
    command="python3",
    args=["pcexpress_mcp_server.py"],
    env={
        "PCEXPRESS_REFRESH_TOKEN": "your_refresh_token",
        # ... other env vars
    }
)

async with stdio_client(server_params) as (read, write):
    async with ClientSession(read, write) as session:
        await session.initialize()

        # List available tools
        tools = await session.list_tools()

        # Call a tool
        result = await session.call_tool("search_products", {
            "query": "ice cream"
        })

📚 Documentation

• QUICKSTART.md - 5-minute setup guide

• SETUP.md - Detailed configuration and login

• DEPLOYMENT.md - Local, Docker, Home Assistant, and Kubernetes

• AUTH_NOTES.md - How the PC id auth flow works

• API_REFERENCE.md - The pcx-bff endpoints, params, and responses

• BANNERS.md - Multi-banner usage guide

• ARCHITECTURE.md - Technical architecture details

• CONTRIBUTING.md - How to contribute

• Reverse-engineering PC Express - The write-up on getting the OAuth secret out of the app

⚠️ Known Limitations

Access-token expiry and cart-id changes used to be the big ones. Both are solved now: the server refreshes its own tokens (rotating and persisting the single-use refresh token), and it reads the cart id from your profile at runtime. What's left:

1. Product search reliability

Problem: Search goes through the banner website's Next.js route, which sits behind Akamai, so it can be flakier than the authenticated pcx-bff calls.

Impact: A search can occasionally fail even when the rest of the API is fine.

Workaround: Retry, or use past orders to find product codes.

Status: 🔍 The app's token-authenticated /products/search route is a candidate replacement.

2. No official API

Problem: This is a reverse-engineered, undocumented API. Loblaw can change it, or rotate the app client secret in a future release and break every copy at once.

Impact: Things can break without notice.

Status: ⚠️ Inherent to the approach.

3. Store-specific inventory

Problem: Product availability and pricing vary by store and banner.

Workaround: Set PCEXPRESS_STORE_ID to the store you want.

Status: ✅ Expected behaviour.

🐛 Troubleshooting

Auth error / "re-run login_pcid.py"

Cause: The refresh token was consumed or revoked. Refresh tokens are single-use, so a shared token chain (two instances on one token) or a long idle period can break it.

Fix: Run python login_pcid.py (or setup.py) and update PCEXPRESS_REFRESH_TOKEN. A normal expired access token is refreshed automatically and needs nothing from you.

"404 Not Found"

Cause: No orders or cart at that banner, or the wrong PCEXPRESS_BANNER code. Cart and customer ids are read from your profile, so a stale id isn't the cause.

Fix: Check PCEXPRESS_BANNER is the banner you actually shop.

"No products found"

Cause: Store doesn't carry product or wrong store ID

Fix: Verify PCEXPRESS_STORE_ID is correct

Tests fail

Cause: Missing dependencies or invalid credentials

Fix:

pip install -r requirements.txt
# if the smoke test reports an auth error, your refresh token expired:
python login_pcid.py

See full troubleshooting guide in SETUP.md

🗺️ Roadmap

Done

• Automatic token refresh (no manual token copying)

• Cart id and customer id auto-discovery

Open

• Token-authenticated product search (replace the website route)

• Store id auto-discovery from homeStore

• Better error messages

Medium Priority

• Shopping list management

• PC Optimum points integration

• Checkout/order placement

• Product details (images, nutrition, etc.)

• Price tracking

Low Priority

• Multiple banner support in single instance

• Recipe suggestions based on cart

• Price comparison across banners

See Issues for full list.

🤝 Contributing

Contributions are welcome! See CONTRIBUTING.md for guidelines.

Quick Contribution Guide

1. Fork the repo

2. Create a feature branch (git checkout -b feature/amazing-feature)

3. Make your changes

4. Test thoroughly (python test_api.py)

5. Commit (git commit -m 'Add amazing feature')

6. Push (git push origin feature/amazing-feature)

7. Open a Pull Request

📜 License

This project is licensed under the GNU Affero General Public License v3.0 - see the LICENSE file for details.

🙏 Acknowledgments

• Thanks to the MCP protocol team at Anthropic

• Inspired by the need for better grocery shopping automation

• Built with reverse-engineering and determination

⚖️ Legal

This project is provided for educational and personal use only.

• Not affiliated with Loblaws Companies Limited

• Uses undocumented API - use at your own risk

• May violate Terms of Service - check before using

• No warranty or guarantee of functionality

• Author not responsible for any consequences of use

By using this software, you agree to take full responsibility for your usage.

📧 Contact

• Issues: GitHub Issues

• Discussions: GitHub Discussions

Made with ❤️ for better grocery shopping

If this project saved you time, consider starring ⭐ the repo!