Cronometer API MCP server

cronometer-api-mcp

<!-- mcp-name: io.github.rwestergren/cronometer-api-mcp -->

Hosted version for Claude.ai, ChatGPT, and Grok coming soon. Join the waitlist →

An MCP (Model Context Protocol) server for Cronometer nutrition tracking, built on the reverse-engineered mobile REST API.

Unlike cronometer-mcp, which takes a comprehensive GWT-RPC approach against Cronometer's web backend, this server talks to the same JSON REST API used by the Cronometer Android app -- with clean payloads and stable, versioned endpoints.

Features

• Food log -- diary entries with food names, amounts, meal groups
• Nutrition data -- daily macro/micro totals and nutrition scores with per-nutrient confidence
• Food search -- search the Cronometer food database, get detailed nutrition info
• Diary management -- add/remove entries, copy days, mark days complete
• Custom foods -- create foods with custom nutrition data
• Macro targets -- read weekly schedule and saved templates
• Fasting -- view history and aggregate statistics
• Biometrics -- weight, body fat, heart rate, and other tracked metrics over a date range

Quick Start

1. Install uv

curl -LsSf https://astral.sh/uv/install.sh | sh

2. Set credentials

export CRONOMETER_USERNAME="your@email.com"
export CRONOMETER_PASSWORD="your-password"

Optional: two-factor authentication

If the account has two-factor authentication enabled, /api/v2/login answers TOTPCODEREQUIRED unless the request carries the current 6-digit code. Give the server the base32 key that Cronometer showed when 2FA was set up (the same key you scanned into your authenticator app) and it derives the code itself at every login (RFC 6238, SHA-1, 30 s period):

export CRONOMETER_TOTP_SECRET="ABCD EFGH IJKL MNOP QRST UVWX YZ23 4567"

Spaces and lowercase are fine. Leave it unset for accounts without 2FA.

Optional: override the account timezone

Diary entries are stamped in your Cronometer account's timezone, which the server reports at login. If that zone is wrong (for example, an older build had reset it) you can force a specific IANA zone without changing your account settings:

export CRONOMETER_ACCOUNT_TZ="America/Los_Angeles"

When set, this takes precedence over both the value reported at login and any cached session, so it also overrides a stale cached timezone.

3. Configure your MCP client

uvx downloads and runs the server on demand -- no separate install step.

OpenCode (opencode.json)

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "cronometer": {
      "type": "local",
      "command": ["uvx", "cronometer-api-mcp"],
      "environment": {
        "CRONOMETER_USERNAME": "{env:CRONOMETER_USERNAME}",
        "CRONOMETER_PASSWORD": "{env:CRONOMETER_PASSWORD}",
        "CRONOMETER_TOTP_SECRET": "{env:CRONOMETER_TOTP_SECRET}",
        "CRONOMETER_ACCOUNT_TZ": "{env:CRONOMETER_ACCOUNT_TZ}"
      },
      "enabled": true
    }
  }
}

Claude Desktop (claudedesktopconfig.json)

Shortened. The full README is on GitHub.