@profullstack/fasting

Fasting App

A comprehensive CLI and Node.js module for 16:8 intermittent fasting with meal tracking, weight monitoring, and fast history with visual charts.

Features

• Fast tracking - Start/end fasts with duration tracking and history
• Meal & drink logging - Track consumption during eating windows
• Automatic calorie estimation using OpenAI's GPT-4o model
• Weight monitoring - Log and visualize weight trends with ASCII charts
• Visual charts - CLI bar charts for fast durations and line charts for weight
• Comprehensive summary - All-in-one dashboard with current status and history
• Flexible timing - Specify custom start/end times for fasts and meals
• Manual calorie override when needed

Setup

• Install dependencies:

pnpm install
pnpm link --global

• Configure OpenAI API key for automatic calorie estimation:

fasting setup

The setup command will prompt you for your OpenAI API key and save it securely to ~/.config/fasting/config.json.

Alternative: You can also set the OPENAI_API_KEY environment variable if you prefer.

Usage

Fast Tracking

# Start a fast (uses current time)
fasting fast start

# Start a fast at a specific time
fasting fast start --time "18:00"
fasting fast start --time "2023-12-01 18:00"

# End a fast (uses current time)
fasting fast end

# End a fast at a specific time
fasting fast end --time "10:00"

Meal & Drink Logging

# Calories are automatically estimated using AI
fasting meal "Grilled chicken breast with quinoa"
fasting drink "Orange juice"

# Specify portion sizes for more accurate estimates
fasting meal "Pizza" --size "2 slices"
fasting drink "Orange juice" --size "32oz"
fasting meal "Salad" -s "large"

Weight & Summary

fasting weight 200
fasting summary                    # Comprehensive dashboard with charts
fasting summary --weight-chart     # Show only weight chart
fasting summary --fast-chart       # Show only fast duration chart

Manual Calorie Override

# Override automatic estimation with manual calories
fasting meal "Chicken Salad" -c 450
fasting drink "Black Coffee" -c 5

# Combine size specification with manual override
fasting drink "Smoothie" --size "16oz" --calories 350

Commands

Core Commands

• fast <start|end> - Start or end a fast with optional custom timing
• meal <description> - Log a meal with automatic calorie estimation
• drink <description> - Log a drink with automatic calorie estimation
• weight <value> - Log weight in pounds
• summary - Show comprehensive dashboard with current status, charts, and history

Setup & Management

• setup - Configure OpenAI API key for automatic calorie estimation
• clean - Delete all stored data (meals, weight, fasts)

Command Options

Fast Command:

• -t, --time <time> - Specify start/end time
  • Examples: "18:00", "2023-12-01 18:00", "10:30"

Meal/Drink Commands:

• -c, --calories <number> - Override automatic calorie estimation with manual value
• -s, --size <size> - Specify portion size for more accurate calorie estimation
  • Examples: "32oz", "large", "2 cups", "small", "16oz", "2 slices", "1 bowl"

Summary Command:

• --weight-chart - Show only weight trend chart
• --fast-chart - Show only fast duration chart

Clean Command:

• --config - Also delete API key configuration

File Structure

Project Files

fasting-app/
├── bin/
│   └── cli.js
├── lib/
│   ├── index.js
│   ├── fasting.js
│   ├── weight.js
│   ├── calorie-estimator.js
│   └── config.js
├── .env.example
└── README.md

User Data (stored in ~/.config/fasting/)

~/.config/fasting/
├── config.json    # API key and settings
├── meals.json     # Meal and drink logs
├── weight.json    # Weight history
└── fasts.json     # Fast tracking history

How It Works

Fast Tracking

The app tracks your intermittent fasting periods:

• Start a fast - Records timestamp and creates an active fast entry
• End a fast - Calculates duration and stores completed fast data
• Custom timing - Specify exact start/end times for accurate tracking
• History & stats - View all past fasts with duration analysis

Calorie Estimation

Automatic calorie estimation using OpenAI's GPT-4o model:

• The description (and optional size) is sent to OpenAI's API
• The AI estimates calories based on the specified portion size or typical serving sizes
• The estimated calories are logged along with your food/drink
• You can specify portion sizes with --size for more accurate estimates
• You can still manually override with the -c flag if needed

Visual Charts

• Weight trends - ASCII line charts showing weight changes over time
• Fast durations - Bar charts displaying recent fast lengths vs. 16h target
• Comprehensive summary - All-in-one dashboard with current fast status, today's meals, statistics, and charts

Size Examples

• Drinks: "32oz", "16oz", "large", "small", "2 cups"
• Meals: "2 slices", "large portion", "small bowl", "1 cup", "half plate"

Configuration & Data Management

The app stores all data in ~/.config/fasting/ for secure, persistent access:

• Configuration: Run fasting setup to configure or update your API key
• Data Storage: All meals, drinks, and weight data are stored locally
• Environment Variable: You can use OPENAI_API_KEY as an alternative (takes precedence)
• Clean Data: Use fasting clean to delete meals/weight data
• Full Reset: Use fasting clean --config to delete everything including API key

Clean Command Options

# Delete meals, weight, and fast data (keeps API key)
fasting clean

# Delete everything including API key configuration
fasting clean --config

If the OpenAI API is unavailable, the app falls back to default estimates (200 calories for meals, 50 for drinks).

Node.js Module API

This package can also be used as a Node.js module in your own applications:

import {
  logMeal, logDrink, getTodaysEntries,
  logWeight, getWeightHistory,
  startFast, endFast, getCurrentFast, getFastHistory, getFastStats
} from 'fasting-app';

// Fast tracking
startFast(); // Start fast now
startFast('2023-12-01 18:00'); // Start fast at specific time
const currentFast = getCurrentFast(); // Get active fast
const completedFast = endFast(); // End current fast

// Log meals and drinks programmatically
logMeal('Grilled chicken breast', 350);
logDrink('Orange juice', 120);

// Get today's entries
const todaysEntries = getTodaysEntries();
console.log(todaysEntries);

// Weight tracking
logWeight(175.5);
const weightHistory = getWeightHistory();

// Fast history and statistics
const fastHistory = getFastHistory(); // Completed fasts only
const fastStats = getFastStats(); // Statistics summary

API Functions

Fast Tracking:

• startFast(startTime?) - Start a new fast (optional custom start time)
• endFast(endTime?) - End current fast (optional custom end time)
• getCurrentFast() - Get active fast or null
• getFastHistory() - Get all completed fasts
• getFastStats() - Get fast statistics (average, longest, etc.)

Meal & Weight Tracking:

• logMeal(description, calories) - Log a meal with description and calorie count
• logDrink(description, calories) - Log a drink with description and calorie count
• getTodaysEntries() - Get all meals and drinks logged today
• logWeight(weight) - Log weight in pounds
• getWeightHistory() - Get complete weight history with timestamps

Note: When using the module API, you need to provide calorie counts manually. Automatic calorie estimation via OpenAI is only available through the CLI commands.

Development & Testing

Running Tests

The project includes comprehensive unit tests for all functionality:

# Run all tests
pnpm test

# Run specific test suites
pnpm test:fast      # Fast tracking tests
pnpm test:charts    # Chart generation tests
pnpm test:fasting   # Meal/drink logging tests
pnpm test:weight    # Weight tracking tests

Test Coverage

• Fast Tracking: Start/end fasts, duration calculation, history management
• Charts: Weight line charts, fast bar charts, summary tables
• Meal/Drink Logging: Entry creation, today's entries filtering
• Weight Tracking: Weight logging, history retrieval, trend analysis

All tests use isolated temporary directories to avoid interfering with real user data.

Examples

The project includes example scripts demonstrating usage:

# Run CLI usage example
pnpm example

# Run API usage example
pnpm example:api

Example Files:

• examples/basic-usage.js - Demonstrates CLI commands and workflow
• examples/api-usage.js - Shows programmatic Node.js module usage