MyFitnessPal MCP Service

A deployable Model Context Protocol (MCP) server for MyFitnessPal that works as a remote Claude connector: food diary, food search, exercises, body measurements, nutrition goals, water intake, and nutrition reports.

This is a fork of AdamWalt/myfitnesspal-mcp-python (MIT, tool implementations) restructured for remote deployment with the OAuth 2.1 / streamable-http transport skeleton from garmin-mcp-service. MyFitnessPal access is via coddingtonbear/python-myfitnesspal.

Tools

Food collections (recent / frequent / my foods)

mfp_get_recent_foods, mfp_get_frequent_foods, and mfp_get_my_foods each take an optional limit (recent/frequent default 10, my-foods default 100, max 100) and response_format (markdown or json). They intentionally use the legacy add-to-diary AJAX endpoints (/food/load_recent, /food/load_most_used, /food/load_my_foods) rather than the newer /food/mine, /meal/mine, or /food/new pages, which can redirect to /account/logout even when diary reads and API-token fetches still work.

Editing diary entries

mfp_get_diary with response_format=json now surfaces an entry_id for each meal entry. Pass that id to:

• mfp_update_food_entry - change meal, quantity, unit (serving-size label, e.g. "350 ml"), or weight_id (raw MFP serving-size option id, overrides unit) for an entry; requires date for historical entries. MyFitnessPal can rewrite an entry during edit, so the response reports current_entry_id and entry_id_changed so you can keep tracking the right row.

• mfp_delete_food_entry - delete an entry by entry_id (requires date for historical entries).

Creating a custom food

mfp_create_food submits a brand-new food to the MyFitnessPal database when mfp_search_food turns up nothing suitable. Required fields are description and the per-serving core macros (calories, fat, carbs, protein); brand, serving_size, servings_per_container, share_public, and the optional micronutrients (fiber, sugar, sodium, cholesterol, vitamins, etc.) round it out. All nutrition values are entered per single serving as defined by serving_size (e.g. serving_size="125 g" with the numbers for a 125 g portion). When the serving unit is a mass unit (g, mg, kg, oz, lb) the gram weight is recorded so MFP's gram-based scaling stays correct.

On success it returns the new food's mfp_id; pass that to mfp_add_food_to_diary to log it (it may take a short moment to also surface in mfp_search_food). Re-running with the same details creates duplicate foods.

share_public=True is irreversible — it submits the food to MyFitnessPal's shared public database, and public foods can no longer be edited or deleted. Leave it False (default) to create a private food you can still delete.

Implementation note: the python-myfitnesspal library's set_new_food() no longer works — MyFitnessPal replaced the server-rendered /food/new Rails form with a client-side SPA that has no authenticity_token input, so the library's HTML scrape raises IndexError: list index out of range. mfp_create_food instead POSTs to the v2/foods API with the account's bearer token (the same mechanism the library still uses for goals).

Authentication: the cookie strategy

MyFitnessPal's login page is captcha-protected, so headless password login is dead - this server never asks for your MFP password. Instead it reads session cookies from one of:

1. Firefox profile sidecar (recommended): log into myfitnesspal.com once, interactively, in a Firefox profile; mount that profile directory read-only into the container at /profile. The server copies cookies.sqlite (and its WAL) to a temp file on each refresh - Firefox's locks don't matter - and extracts the myfitnesspal.com cookies. The copy is cached and only re-read when the file changes, so Firefox can keep running (e.g. a headless Firefox sidecar container you occasionally VNC into to re-login).

2. JSON cookies file: MFP_COOKIES_FILE pointing at {"cookies": {name: value}} (AdamWalt's ~/.mfp_mcp/cookies.json format) or a plain {name: value} dict.

Session cookies expire eventually (~30 days); when tools start failing with auth errors, log into MFP again in that Firefox profile.

Environment Variables

Docker

docker build -t myfitnesspal-mcp-service .

docker run -d -p 8000:8000 \
  -v ~/.mozilla/firefox/abcd1234.default-release:/profile:ro \
  -e MCP_ALLOWED_HOSTS=mfp.example.com \
  -e MCP_RESOURCE_URL=https://mfp.example.com \
  -e MCP_OAUTH_PASSCODE="$(python3 -c 'import secrets; print(secrets.token_urlsafe(32))')" \
  ghcr.io/delize/myfitnesspal-mcp-service:latest

CI builds and pushes ghcr.io/delize/myfitnesspal-mcp-service (amd64 + arm64) on pushes to main and v* tags.

Claude Connector Setup

Same flow as garmin-mcp-service:

1. Deploy behind HTTPS (reverse proxy) with MCP_TRANSPORT=streamable-http, MCP_RESOURCE_URL, and MCP_OAUTH_PASSCODE set.

2. In Claude, add a custom connector with URL https://mfp.example.com/mcp. Leave OAuth Client ID/Secret blank - the server supports dynamic client registration (/register), authorization + PKCE (/authorize, /token).

3. Claude redirects you to the /login passcode page once; enter MCP_OAUTH_PASSCODE. After that the client holds and refreshes its own token.

The passcode proves "the caller knows the passcode", not identity - keep network-level access control (IP allowlist, VPN) in front of any internet-facing deployment. Omitting MCP_OAUTH_PASSCODE/MCP_RESOURCE_URL runs the HTTP server unauthenticated (a warning is logged); only do that on a trusted network.

For local stdio use (Claude Desktop):

{
  "mcpServers": {
    "myfitnesspal": {
      "command": "python",
      "args": ["-m", "myfitnesspal_mcp.server"],
      "env": {
        "MFP_FIREFOX_PROFILE_DIR": "/home/you/.mozilla/firefox/abcd1234.default-release"
      }
    }
  }
}

Troubleshooting

Tools don't appear even though the connector shows "Connected"

Problem: The connector authorizes and shows as Connected, but its tools never surface in a conversation - asking the model to use them, or searching for them, turns up nothing. No error is shown.

Cause: This is almost always a client-side tool-budget limit, not a problem with this server. Claude caps how many tools can be active in a single conversation across all connected servers combined. If another connector exposes a very large tool set, it can consume that budget and silently crowd this server's tools out of the conversation. (Seen in practice with a connector exposing ~170 tools starving this server's handful.)

Confirm / fix:

1. In a fresh conversation, disable the other large connector(s) and check whether these tools now appear. If they do, it was the budget.

2. Keep high-tool-count connectors in separate conversations, or trim their active tools if the client supports per-tool toggles.

3. This server always returns its full tool list regardless - you can verify independently with an authenticated tools/list call against /mcp. If that returns the tools but the client doesn't show them, the gap is on the client side, not here.

Attribution

• Tool implementations: AdamWalt/myfitnesspal-mcp-python (MIT, this repo is a fork - full history preserved)

• MyFitnessPal client library: coddingtonbear/python-myfitnesspal

• OAuth/transport skeleton: garmin-mcp-service

License

MIT - see LICENSE (preserves the original copyright).