weight-mcp

A personal calorie & protein counter delivered as an MCP server for use inside claude.ai. You log meals from photos or text in a normal Claude chat; this server counts them, tracks weight, and renders an interactive dashboard (weight graph + recently eaten) right in the conversation.

Single-user, self-hosted, by design. See SPEC.md for the rationale.

How it works

• MCP server (Streamable HTTP) exposes tools, a prompt, and an MCP Apps dashboard UI to claude.ai.

• In-process OAuth gate: claude.ai drives the full OAuth 2.1 + PKCE + Dynamic Client Registration flow, but the only human step is entering a single shared password (configured in .env). There are no user accounts.

• SQLite stores weights and food logs — one file under data/.

Related MCP server: cronometer-mcp

Tools

Configure

Copy .env.example to .env and set at least WEIGHT_MCP_PASSWORD and WEIGHT_MCP_PUBLIC_BASE_URL. Nutrition sources default to Open Food Facts, filtered to Germany; set WEIGHT_MCP_* to change region, goals, or enable USDA.

Goals support two modes: floor (eat at least the target — the default, for under-eaters) and ceiling (stay under — for weight loss).

Run

Local (dev):

uv sync
cp .env.example .env   # then edit
uv run weight-mcp

Docker (local build):

docker compose up --build

For a real deployment you need public HTTPS (claude.ai connects from Anthropic's cloud, not your device). Copy docker-compose.template.yml, put the server behind a TLS reverse proxy, and set WEIGHT_MCP_PUBLIC_BASE_URL to that origin.

Add to claude.ai

Settings → Connectors → add a custom connector, paste your server's base URL (https://<your-host> — the MCP endpoint and OAuth live at the origin root, so there is no path to append). claude.ai opens the OAuth page; enter your password. Done — start a chat and tell Claude what you ate.

Develop

uv run ruff check .
uv run mypy
uv run pytest