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.

⚠️ 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

🛒 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

Since there's no public API, you need to extract credentials from your browser session:

Method 1: HAR File Export (Recommended)

1. Visit your banner's website (e.g., www.zehrs.ca)
2. Log in to your account
3. Open DevTools (F12) → Network tab
4. ✅ Check "Preserve log"
5. Clear network log
6. Navigate to your cart and past orders
7. Right-click in Network tab → "Save all as HAR with content"
8. Run the credential extractor:

   python extract_credentials.py path/to/file.har
   

This automatically creates your .env file!

Method 2: Manual Extraction

See SETUP.md for detailed manual extraction instructions.

Environment Variables

# OAuth Bearer Token (expires after a few hours)
PCEXPRESS_BEARER_TOKEN=your_bearer_token_here

# Your customer/user ID
PCEXPRESS_CUSTOMER_ID=your_customer_id_here

# Your active cart ID
PCEXPRESS_CART_ID=your_cart_id_here

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

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

🔌 Platform Integration

Home Assistant

# configuration.yaml
mcp:
  servers:
    - name: pcexpress
      command: python3
      args:
        - /path/to/pcexpress_mcp_server.py
      env:
        PCEXPRESS_BEARER_TOKEN: "your_token"
        PCEXPRESS_CUSTOMER_ID: "your_id"
        PCEXPRESS_CART_ID: "your_cart"
        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_BEARER_TOKEN": "your_token",
        "PCEXPRESS_CUSTOMER_ID": "your_id",
        "PCEXPRESS_CART_ID": "your_cart",
        "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_BEARER_TOKEN": "your_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 instructions
• BANNERS.md - Multi-banner usage guide
• ARCHITECTURE.md - Technical architecture details
• CONTRIBUTING.md - How to contribute

⚠️ Known Limitations

1. Token Expiration

Problem: Bearer tokens expire after a few hours

Impact: Server stops working when token expires

Workaround: Re-extract credentials from browser session

Status: ❌ Not solved - Long-term authentication not yet implemented

See #1 - Implement automatic token refresh

2. Product Search Limitations

Problem: Type-ahead search only returns category suggestions, not actual products

Impact: Can't directly get product codes for adding to cart

Workaround: Use past orders to find product codes

Status: 🔍 Investigating alternative endpoints

3. Cart ID Changes

Problem: Cart ID may change on logout/login

Impact: Server needs cart ID updated

Workaround: Re-extract credentials

Status: ⚠️ Needs cart merging implementation

4. No Official API

Problem: Using reverse-engineered, undocumented API

Impact: May break if Loblaws changes their API

Workaround: Monitor for changes, update accordingly

Status: ⚠️ Inherent limitation

5. Store-Specific Inventory

Problem: Product availability varies by store location

Impact: Search results depend on selected store

Workaround: Ensure correct PCEXPRESS_STORE_ID is set

Status: ✅ Expected behavior

🐛 Troubleshooting

"401 Unauthorized"

Cause: Token expired or invalid

Fix: Re-extract credentials from browser

"404 Not Found"

Cause: Cart/Customer ID changed or wrong banner

Fix: Verify PCEXPRESS_BANNER matches token source, re-extract IDs

"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
python extract_credentials.py your_file.har

See full troubleshooting guide in SETUP.md

🗺️ Roadmap

High Priority

• [ ] Automatic token refresh (#1)
• [ ] Full product search (not just type-ahead) (#2)
• [ ] Cart ID change detection (#3)
• [ ] Better error messages (#4)

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

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Made with ❤️ for better grocery shopping

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