🛒 Kroger MCP Server 🛍️ -- FastMCP for Kroger Shopping

A FastMCP server that provides AI assistants like Claude with access to Kroger's grocery shopping functionality through the Model Context Protocol (MCP). This server enables AI assistants to find stores, search products, manage shopping carts, and access Kroger's comprehensive grocery data via the kroger-api python library.

📚 Docs: https://cupofowls.github.io/kroger-api/building-ai-agents/agent-lab — build an AI agent with kroger-mcp, and the full tool reference.

📺 Demo

Using Claude with this MCP server to search for stores, find products, and add items to your cart:

https://github.com/user-attachments/assets/69055f5f-04f5-4ec1-96ac-330aa288fbd1

Changelog

A changelog with recent changes is here.

🚀 Quick Start

Prerequisites

You will need Kroger API credentials (free from Kroger Developer Portal). Visit the Kroger Developer Portal to:

1. Create a developer account
2. Register your application
3. Get your CLIENT_ID, CLIENT_SECRET, and set your REDIRECT_URI

The first time you run a tool requiring user authentication, you'll be prompted to authorize your app through your web browser. You're granting permission to your own registered app, not to any third party.

Installation

⚠️ macOS users must use installation Option 2 ⚠️

Option 1: Using uvx with Claude Desktop (Recommended)

Once published to PyPI, you can use uvx to run the package directly without cloning the repository:

Edit Claude Desktop's configuration file:

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

Linux: ~/.config/Claude/claude_desktop_config.json

Windows: %APPDATA%/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "kroger": {
      "command": "uvx",
      "args": [
        "kroger-mcp"
      ],
      "env": {
        "KROGER_CLIENT_ID": "your_client_id",
        "KROGER_CLIENT_SECRET": "your_client_secret", 
        "KROGER_REDIRECT_URI": "http://localhost:8000/callback",
        "KROGER_USER_ZIP_CODE": "10001"
      }
    }
  }
}

Benefits of this method:

• Automatically installs the package from PyPI if needed
• Creates an isolated environment for running the server
• Makes it easy to stay updated with the latest version
• Doesn't require maintaining a local repository clone

Option 2: Using uv with a Local Clone

First, clone locally:

git clone https://github.com/CupOfOwls/kroger-mcp

Then, edit Claude Desktop's configuration file:

{
  "mcpServers": {
    "kroger": {
      "command": "uv",
      "args": [
        "--directory",
        "/path/to/cloned/kroger-mcp",
        "run",
        "kroger-mcp"
      ],
      "env": {
        "KROGER_CLIENT_ID": "your_client_id",
        "KROGER_CLIENT_SECRET": "your_client_secret", 
        "KROGER_REDIRECT_URI": "http://localhost:8000/callback",
        "KROGER_USER_ZIP_CODE": "10001"
      }
    }
  }
}

Option 3: Installing From PyPI

# Install with uv (recommended)
uv pip install kroger-mcp

# Or install with pip
pip install kroger-mcp

Option 4: Installing From Source

# Clone the repository
git clone https://github.com/CupOfOwls/kroger-mcp
cd kroger-mcp

# Install with uv (recommended)
uv sync

# Or install with pip
pip install -e .

Configuration

Pass the settings in the env block of your MCP client's JSON config, or put them in a .env file in the directory you start the server from (only its KROGER_* settings are read):

# Required: Your Kroger API credentials
KROGER_CLIENT_ID=your_client_id_here
KROGER_CLIENT_SECRET=your_client_secret_here
KROGER_REDIRECT_URI=http://localhost:8000/callback

# Optional: Default zip code for location searches
KROGER_USER_ZIP_CODE=90274

# Optional: The scopes the user grants at sign-in (default: product.compact cart.basic:write).
# Add profile.compact for get_user_profile, but only if your app is registered for the Identity API.
# KROGER_USER_SCOPES=product.compact cart.basic:write profile.compact

Running the Server

# With uv (recommended)
uv run kroger-mcp

# With uvx (directly from PyPI without installation)
uvx kroger-mcp

# Or with Python directly
python server.py

# Options such as an HTTP transport (see kroger-mcp --help)
uvx kroger-mcp --transport streamable-http --port 8000

# With FastMCP CLI for development
fastmcp dev server.py --with-editable .

🛠️ Features

💬 Built-In MCP Prompts

• Shopping Path: Find optimal path through store for a grocery list
• Pharmacy Check: Check if pharmacy at preferred location is open
• Store Selection: Help user set their preferred Kroger store
• Recipe Shopping: Find recipes and add ingredients to cart

📚 Available Tools

Location Tools

Product Tools

Cart Tools

Information Tools

Profile Tools

start_authentication asks the user to grant product.compact and cart.basic:write, which the cart tools need. get_user_profile also needs profile.compact, from the Identity API. An app may request only the scopes of the API products it is registered for, and Kroger refuses the whole sign-in with invalid_scope when one is missing, so profile.compact is not requested by default. To use get_user_profile, register the Identity API for your app in the Kroger Developer Portal, set KROGER_USER_SCOPES to product.compact cart.basic:write profile.compact, restart the server, and sign in again.

Utility Tools

🧰 Local-Only Cart Tracking

Since the Kroger API doesn't provide cart viewing functionality, this server maintains local tracking:

Local Cart Storage

• File: kroger_cart.json
• Contents: Current cart items with timestamps
• Automatic: Created and updated automatically

Order History

• File: kroger_order_history.json
• Contents: Historical orders with placement timestamps
• Usage: Move completed carts to history with mark_order_placed

Where these files live

State files (cart, order history, preferences) and OAuth tokens are stored in the first matching location:

1. $KROGER_TOKEN_DIR, if you set that environment variable
2. $XDG_DATA_HOME/kroger-mcp/ (defaults to ~/.local/share/kroger-mcp/) on macOS/Linux
3. %APPDATA%\kroger-mcp\ on Windows

They are never written to the current working directory, which may be read-only or change between sessions under MCP hosts like Claude Desktop. Files from older versions that live in the working directory are migrated automatically on first use.

Several server processes can share the directory, for example one for Claude Desktop and one for Claude Code. Each change to a state file, and each renewal of the sign-in, holds a lock on that file (a .lock file beside it), so the processes do not overwrite each other's changes or sign each other out.

⚡ Concurrent calls

Each tool that calls the Kroger API or reads a state file runs in a worker thread, so a slow Kroger request holds up only its own call. The assistant's other calls go on, and so do the other clients of a server that uses the streamable-http or sse transport. Cancelling a call answers at once, but the request it already sent still finishes: a cancelled add_items_to_cart can still add the items.

⚠️ Error Handling

A tool that fails returns an MCP error result (isError: true), so the assistant can see what went wrong and correct its next call:

• Text content: what went wrong, followed by Next step: and what to do about it, often naming the tool to call.
• Structured content: an error object with a stable type, the message, the next_step, the tool, and every detail the kroger-api package has about a Kroger API error: status_code, Kroger's kroger_code and kroger_message, the request method and url, the correlation_id, a hint, and the response_body.

A cart add that times out, loses its connection after the request may have been sent, or gets a 5xx has outcome_unknown: true. Kroger may have added the items anyway, so the next step says to have the user check their cart before adding again, instead of retrying.

A search that finds nothing is not an error: it returns count: 0 and a message. The full list of error types is in the MCP tools reference.

🚧 Kroger Public API Limitations

• View Only: The remove_from_cart and clear_current_cart tools ONLY affect local tracking, not the actual Kroger cart
• Local Sync: Use these tools only when the user has already removed items from their cart in the Kroger app/website
• One-Way: Items can be added to the Kroger cart but not removed through the Public API. The Partner API would allow these things, but that requires entering a contract with Kroger.

Note: Rate limits are enforced per endpoint, not per operation. You can distribute calls across operations using the same endpoint as needed.

🏫 Basic Workflow

1. Set up a preferred location:

   User: "Find Kroger stores near 90274"
   Assistant: [Uses search_locations tool]
   User: "Set the first one as my preferred location"
   Assistant: [Uses set_preferred_location tool]
   

   Copy

2. Search and add products:

   User: "Add milk to my cart"
   Assistant: [Uses search_products, then add_items_to_cart]
   
   User: "Add bread, eggs, and cheese to my cart"
   Assistant: [Uses search_products for each, then bulk_add_to_cart]
   

   Copy

3. Manage cart and orders:

   User: "What's in my cart?"
   Assistant: [Uses view_current_cart tool to see local memory]
   
   User: "I placed the order on the Kroger website"
   Assistant: [Uses mark_order_placed tool, moving current cart to the order history]
   

   Copy

🍪 OAuth2 Authentication

When Claude attempts to modify your Kroger account, you will be asked to insert a link into your browser that will handle authentication and allow Claude to add/remove items from your cart. Ensure that you have already made a Kroger account (this is different than your Kroger development account) before attempting to paste this link into your browser to initiate authentication.

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

⚠️ Disclaimer

This is an unofficial MCP server for the Kroger Public API. It is not affiliated with, endorsed by, or sponsored by Kroger.

For questions about the Kroger API, visit the Kroger Developer Portal or read the kroger-api package documentation.