Hermes Grocy MCP

Grocy MCP

A Model Context Protocol (MCP) server for Grocy, the self-hosted household ERP for groceries, inventory, chores, batteries, recipes, tasks, and shopping lists.

This server focuses on AI-friendly household operations that are awkward through generic REST clients:

• Inspect Grocy system/version status
• List, search, and inspect products
• Read current stock, volatile stock, product stock details, and individual stock entries
• List current shopping list items and add/remove products from shopping lists
• Look up products by barcode/Grocycode
• List and inspect any /api/objects/{entity} entity
• Create/update generic entity objects from JSON
• Add, consume, and inventory product stock
• Add/remove product amounts from shopping lists

Why this exists

Grocy has a strong REST API, but MCP coverage is sparse and usually either incomplete or tightly coupled to one client's workflow. This package gives Hermes, Claude Desktop, Cursor, and other MCP clients a small, explicit, documented tool surface.

Installation

pipx install git+https://github.com/rusty4444/grocy-mcp.git

Or from a checkout:

python -m venv .venv
source .venv/bin/activate
pip install -e .

Configuration

The server reads configuration from environment variables:

Variable	Required	Default	Description
GROCY_BASE_URL	No	https://demo.grocy.info	Grocy base URL, with or without /api
GROCY_API_KEY	No for public/demo read-only instances, yes for private/write access	unset	Grocy API key sent as GROCY-API-KEY
GROCY_TIMEOUT	No	20	HTTP timeout in seconds

Grocy API keys are managed in Grocy under Manage API keys. The API accepts the GROCY-API-KEY header.

MCP client config

{
  "mcpServers": {
    "grocy": {
      "command": "grocy-mcp",
      "env": {
        "GROCY_BASE_URL": "https://grocy.example.com",
        "GROCY_API_KEY": "your-api-key"
      }
    }
  }
}

Tools

Tool	Purpose
grocy_system_info	Grocy version and runtime details
grocy_list_products	List configured products
grocy_search_products	Search products by name/description
grocy_get_product	Fetch one product object
grocy_lookup_product_by_barcode	Resolve a barcode/Grocycode
grocy_stock_overview	Current stock rows
grocy_volatile_stock	Due, overdue, expired, or missing products
grocy_product_stock_details	Detailed stock state for one product
grocy_product_stock_entries	Individual stock entries in next-use order
grocy_common_entities	Common generic entity names useful with CRUD tools
grocy_list_shopping_lists	Configured shopping lists
grocy_list_shopping_list_items	Current shopping list rows, optionally filtered by list id
grocy_list_entity	List any generic Grocy entity
grocy_get_entity_object	Fetch any generic entity object
grocy_create_entity_object	POST a generic entity object from JSON
grocy_update_entity_object	PUT a generic entity object from JSON
grocy_add_stock	Add product amount to stock
grocy_consume_stock	Consume/remove product amount from stock
grocy_inventory_product	Set product inventory amount
grocy_add_product_to_shopping_list	Add a product to a shopping list
grocy_remove_product_from_shopping_list	Remove a product from a shopping list
grocy_set_userfields	Set userfield values on an entity object
grocy_list_chores	List chores including computed next-due times
grocy_execute_chore	Execute (mark done) a chore, optionally backdated
grocy_list_tasks	List tasks

Development and validation

python -m venv .venv
source .venv/bin/activate
pip install -e '.[dev]'
ruff check .
pytest
python scripts/live_readonly_test.py

The live read-only test defaults to https://demo.grocy.info, avoiding mutations on shared infrastructure. It has been validated against Grocy API 4.6.0. Use a private Grocy instance plus GROCY_API_KEY for write-path testing.

Safety

Write-capable tools directly mutate Grocy data. Prefer read-only tools when using public demos. Keep GROCY_API_KEY in MCP client environment config or a secret manager, never in source control.