Nutrition MCP

Personal calorie and nutrient tracking MCP server. Looks up food via OpenFood Facts, logs meals with portion-scaled nutrients, and tracks daily intake against gout and hypertension-aware goals.

Tech Stack

• Rust — Systems language
• rmcp — Official Rust MCP SDK (streamable HTTP transport)
• axum 0.8 — Web framework for HTTP transport + auth middleware
• sqlx 0.8 — Async SQLite
• reqwest 0.12 — HTTP client for OpenFood Facts APIs
• SQLite with FTS5 — Local database + full-text search

Health Context

This tracker is configured for two specific health conditions:

• Gout — Tracks fructose (15g/day limit) and alcohol (0 limit). Both are known gout triggers.
• Hypertension — Tracks salt (6g/day, NHS guideline), potassium (3500mg, helps lower BP), calcium (700mg), magnesium (300mg), and cholesterol (300mg).

14 Tracked Nutrients

Nutrient	OFF field	Default goal	Unit	Reason
Energy	energy-kcal_100g	2500	kcal	General
Protein	proteins_100g	150	g	General
Carbohydrates	carbohydrates_100g	300	g	General
Fat	fat_100g	70	g	General
Fiber	fiber_100g	30	g	General
Sugars	sugars_100g	90	g	General
Saturated fat	saturated-fat_100g	20	g	Hypertension
Salt	salt_100g	6	g	Hypertension (key)
Fructose	fructose_100g	15	g	Gout (key)
Alcohol	alcohol_100g	0	% vol	Gout (key)
Potassium	potassium_100g	3500	mg	Hypertension (key)
Calcium	calcium_100g	700	mg	Hypertension
Magnesium	magnesium_100g	300	mg	Hypertension
Cholesterol	cholesterol_100g	300	mg	Hypertension

MCP Tools (13)

Food Lookup

• search_food(query, page_size?) — Full-text search via OpenFood Facts Search-a-licious
• get_food_by_barcode(barcode) — Product lookup by barcode via OFF API v3

Logging

• log_food(product_code, grams?, servings?, date?, meal?) — Log OFF product with portion scaling
• log_custom_food(name, calories, nutriments?, grams, date?, meal?) — Log homemade/restaurant food
• delete_entry(id) — Remove a logged entry

Summary & History

• daily_summary(date?) — All 14 nutrients vs goals, remaining, entry list
• history(days?) — Last N days of totals (default 7)
• list_entries(date?) — List entries with IDs for deletion

Goals

• get_goals() — Current daily nutrient targets
• set_goals(goals) — Update goals (partial merge)

Weight

• log_weight(weight_kg, date?) — Log body weight in kg
• weight_history(days?) — Weight trend (default 30 days)

Future

• bulk_import(parquet_url?) — Stub for offline Parquet import

Build

cargo build --release

Binary: target/release/nutrition-mcp

Environment Variables

Variable	Default	Description
NUTRITION_MCP_BIND	0.0.0.0:9432	Bind address
NUTRITION_MCP_API_KEY	(random UUID)	Bearer token for auth
NUTRITION_MCP_DB_PATH	~/.local/share/nutrition/nutrition.db	SQLite database path
NUTRITION_MCP_OFF_USER_AGENT	NutritionMCP/0.1.0 (personal use)	User-Agent for OFF API

Run

NUTRITION_MCP_API_KEY=your-secret-key \
NUTRITION_MCP_BIND=0.0.0.0:9432 \
./target/release/nutrition-mcp

Health Check

curl http://localhost:9432/health
# → OK

MCP Connect

curl -X POST http://localhost:9432/mcp \
  -H "Authorization: Bearer your-secret-key" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","method":"initialize","params":{"protocolVersion":"2025-11-25","capabilities":{},"clientInfo":{"name":"test","version":"0.1"}},"id":1}'

Deploy as systemd Service

# Create service file
cat > ~/.config/systemd/user/nutrition-mcp.service << 'EOF'
[Unit]
Description=Nutrition MCP Server
After=network.target

[Service]
ExecStart=%h/workspace/nutrition-mcp/target/release/nutrition-mcp
Environment=NUTRITION_MCP_BIND=0.0.0.0:9432
Environment=NUTRITION_MCP_API_KEY=your-secret-key
Environment=NUTRITION_MCP_DB_PATH=%h/.local/share/nutrition/nutrition.db
Environment=NUTRITION_MCP_OFF_USER_AGENT=NutritionMCP/0.1.0 (personal use; contact: atradeus@pm.me)
Restart=on-failure
RestartSec=5

[Install]
WantedBy=default.target
EOF

# Enable linger (survive logout)
loginctl enable-linger $USER

# Start
systemctl --user daemon-reload
systemctl --user enable --now nutrition-mcp

Connect from Hermes

hermes mcp add nutrition --url http://localhost:9432 --header "Authorization: Bearer your-secret-key"

Connect from Laptop (LAN)

hermes mcp add nutrition --url http://chronos:9432 --header "Authorization: Bearer your-secret-key"

Data Sources

• OpenFood Facts Search-a-licious — Full-text product search
• OpenFood Facts API v3 — Barcode lookups
• OpenFood Facts Parquet — Future offline bulk import (7.82 GB, 4.7M products)

All food data is cached locally in SQLite with FTS5 for instant repeat lookups.

Architecture

See AGENTS.md for full project instructions, conventions, and module map.

License

MIT