grocy-mcp

An MCP server for Grocy, so an AI assistant can read and manage your pantry: what's in stock, what's going off, what needs buying, and what you just used.

27 tools covering stock, the product catalog and the shopping list. Every call reads live from Grocy — there is no cache to go stale.

You: what's going off this week, and can I make something with it?
     ...
You: right, I used the last of the coconut milk and two of the tomatoes
     ...
You: add coconut milk to the shopping list

Install

Not on PyPI yet — install from the repo:

pip install git+https://github.com/anishanilkumar/grocy-mcp          # stdio only
pip install 'grocy-mcp[http] @ git+https://github.com/anishanilkumar/grocy-mcp'

The http extra adds PyJWT and cryptography, needed only to verify OAuth bearer tokens when serving over HTTP. A stdio server needs neither.

You need a Grocy API key: in Grocy, wrench icon → Manage API keys → add.

export GROCY_API_URL=https://grocy.example.com/api
export GROCY_API_KEY=...

Related MCP server: MCP Grocy API

Use it from a local client

Most MCP clients launch the server themselves over stdio. For Claude Desktop, add this to claude_desktop_config.json:

{
  "mcpServers": {
    "grocy": {
      "command": "grocy-mcp",
      "env": {
        "GROCY_API_URL": "https://grocy.example.com/api",
        "GROCY_API_KEY": "your-api-key",
        "GROCY_MCP_CONFIG": "/path/to/pantry.toml"
      }
    }
  }
}

GROCY_MCP_CONFIG is optional — see Configuration.

Tools

Stock

Catalog — search_products, get_conventions, create_product, update_product, delete_product, add_barcode, remove_barcode

Shopping list — list_shopping_list, add_to_shopping_list, remove_from_shopping_list, check_off_shopping_item, add_missing_to_shopping_list, clear_shopping_list

It refuses rather than guessing

Most of the value over raw API calls is in what these tools won't do. Grocy will happily take stock negative or move a batch out of a shelf it isn't on; an agent that does so is very hard to notice afterwards.

• An ambiguous product name raises with the candidates listed, instead of picking one. A wrong guess silently moves the wrong product's stock.

• Consuming, opening or transferring more than is on hand is refused.

• A transfer with stock split across shelves refuses until you say which shelf.

• Changing a product's unit while it holds stock is refused — Grocy would reinterpret the existing amount in the new unit.

• A barcode already belonging to another product is refused.

• Adding a misspelled product to the shopping list is refused rather than quietly written as a free-text note that can never be matched back to stock.

• Deleting a product that still has stock is refused.

Every stock write returns a transaction_id, so mistakes get undone properly rather than cancelled out with an opposite booking that leaves both rows in the journal and invents a best-before date.

Configuration

Optional, and only for things Grocy has no field for. Locations, categories and units are always read live from your instance, so they are never configured here and cannot drift.

What you can configure is the advice: what each location is for, how long things keep when the package has no date, how you name products. That is what makes an agent's guesses good, and it is different in every kitchen.

[pantry]
summary = "Household inventory for a two-person kitchen."
soon_days = 7

expiry_guidance = """
Best-before estimates when the package date is unknown:
  fresh veg ~1 week    frozen ~2 months    whole spices ~3 years
"""

[pantry.location_notes]
"Fridge" = "Perishables: dairy, eggs, opened jars"
"Freezer" = "Frozen items, meat, fish"

See examples/pantry.toml for every option. Point at it with GROCY_MCP_CONFIG=/path/to/pantry.toml or --config.

With no config file the server still works — it just describes your instance without opinions about it.

Serving over HTTP

For a remote client (e.g. a Claude custom connector) rather than a local one. Bind to loopback and put a reverse proxy in front to terminate TLS.

grocy-mcp --transport http --public-host grocy-mcp.example.com

Authentication is required by default over HTTP, because a write-capable server without it is the kind of default nobody notices until it is reachable from somewhere it shouldn't be. Tokens are validated locally against the issuer's published keys — no introspection call, so a public PKCE client needs no secret here.

export GROCY_MCP_OIDC_ISSUER=https://auth.example.com/realms/home
export GROCY_MCP_OIDC_AUDIENCE=grocy-mcp     # usually the client id
export GROCY_MCP_OIDC_SCOPES=mcp             # optional, space separated

The JWKS endpoint is discovered from the issuer. Set GROCY_MCP_OIDC_JWKS_URI if your provider doesn't publish standard discovery metadata — Kanidm, for instance, serves per-client keys at <issuer>/public_key.jwk, which this tries as a fallback.

--no-auth exists for a server on an interface nothing untrusted can reach. Be sure that's true before using it.

The SSE response must not be buffered, and the timeouts need raising:

location /mcp {
    proxy_pass http://127.0.0.1:8765;
    proxy_http_version 1.1;
    proxy_buffering off;
    proxy_read_timeout 3600s;
}

# RFC 9728 protected-resource metadata, served at the path-suffixed location.
location /.well-known/oauth-protected-resource/mcp {
    proxy_pass http://127.0.0.1:8765;
}

Two things are easy to get wrong here. The metadata lives at the path-suffixed location (…/oauth-protected-resource/mcp), not the bare one. And --public-url must equal the URL exactly as the client has it configured, path included, or the metadata is rejected as not describing this server.

Requirements

Python 3.11+, and Grocy 4.x. Developed against 4.6; every endpoint used is checked against the instance's own OpenAPI spec.

Development

pip install -e '.[http,dev]'
pytest

The tests run against an in-memory fake Grocy, so they need no instance and no network. They assert on the request bodies the tools send, not just their return values.

License

MIT