Nutrition MCP

A remote MCP server for personal nutrition tracking — log meals with calories, macros, fiber and total sugar, log water and body weight, review nutrition history, and import an existing food diary from another app, all through conversation. Alcohol tracking is opt-in and off by default.

Help me pay for the servers on Patreon

Quick Start

The current runtime is a single-user, no-auth Bun server backed by local PostgreSQL. It exposes the MCP protocol at POST /mcp; there is no Supabase, OAuth, email/password, or account-registration step.

bun install
cp .env.example .env
# Ensure PostgreSQL is running and DATABASE_URL points at the database to use.
bun run start

Then configure an MCP client with http://localhost:8080/mcp. The hosted URL https://nutrition-mcp.com/mcp is a deployment-specific endpoint, not a different authentication flow.

Switching from another tracker? See the nutrition-app alternatives — how it compares to MyFitnessPal, Cronometer, Lose It!, MacroFactor, Yazio, and Lifesum. Bring your history with you: say "import my meals" and an importer opens in the chat, where you pick the CSV you exported from your old app, map its columns, and check what will be added before anything is saved. Exports from MyFitnessPal, Cronometer, Lose It! and MacroFactor are recognised automatically; any other CSV works by mapping its columns yourself. In clients that can't show in-chat panels, paste the export instead and the AI imports it for you. If your export has an alcohol column and you want it kept, turn alcohol tracking on before importing — the importer skips that column while tracking is off, and re-importing the same file later won't backfill it.

Demo

Read the story behind it: How I Replaced MyFitnessPal and Other Apps with a Single MCP Server

Tech Stack

• Bun — runtime and package manager
• Hono — HTTP framework
• MCP SDK — Model Context Protocol over Streamable HTTP
• PostgreSQL — local database, configured with DATABASE_URL
• No authentication — this runtime is single-user and exposes /mcp directly

MCP Tools

Tool	Description
log_meal	Log a meal with description, type, calories, macros, fiber, total sugar, alcohol, notes — from text or a photo of your plate
start_meal_import	Open the in-chat CSV importer: pick an export from another app, map its columns, preview, confirm
bulk_import_meals	Write up to 50 imported rows per call — each row validated, duplicates skipped so a re-send is safe
lookup_barcode	Look up a packaged product's label nutrition by barcode via Open Food Facts (read from a photo or typed)
get_meals_today	Get all meals logged today
get_meals_by_date	Get meals for a specific date (YYYY-MM-DD)
get_meals_by_date_range	Get meals between two dates (inclusive)
search_meals	Search past meals by keyword, grouped into recurring variations (counts, last logged, typical macros)
get_nutrition_summary	Daily nutrition totals + goal progress for a date range
update_meal	Update any fields of an existing meal
delete_meal	Delete a meal by ID
set_nutrition_goals	Set daily calorie, macro, fiber and water targets to reach, sugar and alcohol limits to stay under, plus an optional target weight
get_nutrition_goals	Get the current daily targets and limits
get_goal_progress	Get intake vs. targets and limits for a given day (default: today), plus latest weight vs. target
log_water	Log a hydration entry in milliliters
get_water_today	Get today's water intake total and entries
get_water_by_date	Get water intake for a specific date
delete_water	Delete a water log entry by ID
log_weight	Log a body-weight measurement in kg or lb (converted and stored server-side)
get_weight_today	Get today's weight entries
get_weight_by_date	Get weight entries for a specific date
get_weight_by_date_range	Get weight entries between two dates (inclusive), grouped by day
get_weight_trends	Weight trend: latest, overall change, 7/14/30-day moving averages, min/max, and goal progress
update_weight	Update an existing weight entry
delete_weight	Delete a weight entry by ID
set_weight_unit	Set the preferred weight unit (kg or lb; null to clear)
get_weight_unit	Get the preferred weight unit
get_trends	7/14/30-day averages, std dev, streaks, day-of-week, best/worst day
get_meal_patterns	Pre-aggregated behavioural patterns (breakfast effect, late dinner, weekend vs weekday, outliers)
export_meals	Export all meals as a CSV and return a 60-minute download link
set_timezone	Set the user's IANA timezone (e.g. America/Los_Angeles)
get_timezone	Get the user's configured timezone
set_widget_display	Enable or disable the in-chat visual widgets (dashboards, rings, charts); enabled by default
get_widget_display	Get whether the in-chat visual widgets are enabled
set_alcohol_tracking	Turn alcohol tracking on or off (off by default) and choose US standard drinks or UK units; turning it off hides alcohol rather than deleting it
get_alcohol_tracking	Get whether alcohol tracking is on and which standard drink it's displayed in
delete_account	Permanently delete account and all associated data

Food-tracking storage and scope

Food tracking uses an append-only meal_events aggregate: each correction creates a new version and advances the root pointer; historical versions and evidence remain readable. The legacy meal tables are reset destructively by migration 002 when it is applied, so take an export before upgrading. Event media bytes live under MEDIA_ROOT; PostgreSQL stores only the generated event/version/content-hash key and metadata. DATABASE_URL_TEST points integration tests at an isolated PostgreSQL database (the local default is postgres://localhost:5432/nutrition_mcp_test).

The sync journal records explicit MyFitnessPal add authorization as pending only. This slice intentionally makes no real MFP calls and ships no automatic backup scheduler or cloud backup service; backup manifests are a contract for an operator-run backup, not proof that backups ran.

Food-import calls accept at most 50 rows. Each row is limited to 20,000 kcal, 5,000 g for ordinary macros, and 500 g of alcohol; split larger files into chunks while keeping all rows for a calendar date together. The importer is idempotent, but it is not an MFP writer or a cloud backup system.

URI	Description
nutrition://weekly-summary	Rolling 7-day digest (averages vs targets, best/roughest day) for proactive pulls

Self-hosting

This section describes the current local PostgreSQL/Bun runtime. Older Supabase, OAuth, and email/password deployment notes are obsolete and must not be used for this checkout.

1. PostgreSQL and migrations

Create the database named by DATABASE_URL, then apply the migrations in order:

psql "$DATABASE_URL" -v ON_ERROR_STOP=1 -f db/migrations/001_initial_schema.sql
psql "$DATABASE_URL" -v ON_ERROR_STOP=1 -f db/migrations/002_food_tracking.sql

Migration 002_food_tracking.sql is destructive: it deletes the legacy meals rows and drops the legacy meals table before creating the append-only food-tracking schema. Export any data you need before applying it. Migration 002 is safe to rerun after a complete or interrupted run, but it is not a backfill and there is no rollback for the legacy meal reset.

2. Environment variables

Variable	Description
DATABASE_URL	PostgreSQL connection string for the runtime database (default example: postgres://localhost:5432/nutrition_mcp)
DATABASE_URL_TEST	Isolated PostgreSQL database used by integration tests (default example: postgres://localhost:5432/nutrition_mcp_test)
MEDIA_ROOT	Local directory for event media bytes (default example: ./data/media); PostgreSQL stores metadata and keys, not the bytes
OFF_USER_AGENT	Open Food Facts User-Agent for barcode lookups, in the form AppName (email)
PORT	Server port (default: 8080)

Making it yours: The public site includes the maintainer's personal bits — Google Analytics, Patreon/GitHub/contact links, and the nutrition-mcp.com domain. Run bun run depersonalize to strip them all in one pass (analytics + CSP, the Support/Contact sections, social links, and the domain → a your-domain.com placeholder). Use bun run depersonalize --dry to preview without writing. Afterwards, swap in your own public/og.png, favicon.ico, and apple-touch-icon.png, and replace the domain placeholder with your real domain.

Agent-driven meal capture

The complete boundary, lifecycle, provenance, migration, rollback, and retry contract is documented in docs/food-tracking-agent-driven.md.

The append-only meal-event path is also exposed as a transport-neutral, durable capture flow for an agent host. Hermes supplies raw message/evidence/media metadata, clarification answers, prepared drafts, and provider result bundles; this server does not receive Telegram updates, download media, run STT/OCR/vision, or call external MCP servers.

Use start_meal_capture, append_meal_capture_message, answer_meal_capture, and save_meal_capture_draft for restart-safe multi-turn storage. confirm_meal_capture is the explicit authorization gate: only the user's unambiguous add command (including добавь) commits one prepared capture to one meal_event; MyFitnessPal authorization remains a pending journal row, never a claim of successful sync. validate_calculation_bundle accepts and validates Hermes-supplied nutrition-local, own, and myfitnesspal result metadata. Canonical nutrition is recomputed by the existing consensus-10pct-v1 policy; missing, failed, and unavailable values are not treated as zero.

Migration order for a new or test database is 001_initial_schema.sql, 002_food_tracking.sql, then 003_meal_captures.sql.

bun install
cp .env.example .env   # set DATABASE_URL and any local overrides
bun run dev             # starts with hot reload on http://localhost:8080

Run the actual MCP server with bun run start (or bun run src/index.ts). GET /health returns ok; MCP clients must use POST /mcp.

For the full test suite, point integration tests at a disposable database:

DATABASE_URL_TEST=postgres://localhost:5432/nutrition_mcp_test bun test
bun run typecheck
bun run format:check

Connect to Claude.ai

1. Start the server locally with bun run start.
2. Add a custom connector named Nutrition Tracker.
3. Use http://localhost:8080/mcp as the MCP URL.
4. Connect; no sign-in or registration is expected.

API Endpoints

Endpoint	Description
GET /health	Health check
POST /mcp	Stateless MCP endpoint (no auth)
GET /favicon.ico	Server icon

The old OAuth discovery, registration, authorize, approve, and token paths are not part of this runtime.

Deploy

The project includes a Dockerfile for container-based deployment. The container still requires a reachable PostgreSQL DATABASE_URL; it does not provide Supabase or OAuth services.

1. Push your repo to a hosting provider (e.g. DigitalOcean App Platform)
2. Set the runtime environment variables listed above, including DATABASE_URL
3. The app auto-detects the Dockerfile and deploys on port 8080
4. Point your domain to the deployed URL

License

MIT