🍃 MacroLens

AI-powered, fully on-device iOS nutrition & body-recomposition tracker. Snap a photo of a meal, get an instant macro + micronutrient breakdown, and let an adaptive coach steer your targets toward your goals.

MacroLens keeps all of your data on-device (SwiftData). The only thing that ever leaves your phone is a single meal-photo analysis request to the Google Gemini API.

✨ Features

• 📸 AI meal analysis — photo(s) + a short description → calories, macros, sugar, and a per-ingredient breakdown via Gemini. Every number is editable before saving.
• 📊 Today dashboard — calorie ring, macro rings, and a sugar bar. Tap any metric to drill into exactly which foods contributed — down to each ingredient in a composite meal.
• 🧬 Vitamins & minerals — per-ingredient micronutrient estimates with RDA progress bars and deficiency / excess flags, driven by an extensible nutrient catalog.
• 🥤 Drinks & 💧 hydration — log caloric beverages (protein/carbs/fat/sugar) and water, with per-beverage hydration coefficients and a 7-day hydration chart.
• 💊 Supplements & creatine — manual logging (e.g. a 5 g creatine scoop) plus creatine estimated from food, combined into a daily total.
• 🧠 Adaptive nutrition planning — estimates your real maintenance calories from intake + weight trend (energy balance) and proposes target adjustments, with a plain-language explanation of what changed and why.
• 🤖 Coach — prioritized, trend-based, encouraging recommendations generated from your history, plus a conversational chat coach.
• 📷 Per-100 g label entry — type a package's per-100 values and how much you had; the totals are computed for you.
• 🗓️ History — a day-by-day timeline of meals, drinks, and water; calendar view; swipe to delete; tap a meal to edit or re-analyze.
• ⚖️ Body metrics — weight & body-fat logging with a Swift Charts trend, optional HealthKit-ready design.
• 🌙 Configurable day boundary — late-night meals (before, say, 3 AM) count toward the previous day.
• 🔔 Reminders — on-device meal & hydration reminders (no paid entitlement required).
• 🌍 Localized — English, Russian, and Kazakh.

🛠 Tech stack

• Swift + SwiftUI, targeting iOS 26
• SwiftData for all local persistence
• Swift Charts for trends
• PhotosUI + camera for meal photos
• Google Gemini API (gemini-3-flash-preview, free tier) as the single networking layer
• No backend, no cloud database, no third-party analytics

🏗 Architecture

MacroLens/
├── MacroLensApp.swift     # @main, SwiftData ModelContainer
├── Models/                # @Model types, the extensible Nutrient catalog, computed DayLog
├── Services/              # Gemini, HistoryAnalyzer, AdaptivePlanner, Keychain, AppRouter,
│                          # AppShortcuts, Notifications, ImageProcessing, Localization, DayBoundary
├── DesignSystem/          # "Calm Instrument" — Theme (tokens/motion) + reusable Components
└── Views/                 # Today · Add (Meal/Drink/Supplement) · History · Body · Coach · Settings

An extensible nutrient catalog (Models/Nutrient.swift) is the single source of truth: it drives the Gemini response schema, the per-metric drill-downs, and RDA tracking — adding a new vitamin, mineral, or supplement is a one-line change.

The UI is built on a single design system (DesignSystem/): one card, one ring scale, one status ramp, one row — so every tab reads as one system, in light & dark and across English/Russian/Kazakh. Back-tap shortcuts ("Log Meal" / "Log Drink") deep-link into logging via App Intents.

🚀 Getting started

Requirements: Xcode 26, an iPhone on iOS 26, and an Apple ID (a free one works — this app is built for personal sideloading).

1. git clone https://github.com/YeraSss/MacroLens.git
2. Open MacroLens.xcodeproj.
3. Select the MacroLens target → Signing & Capabilities → choose your team (free Apple ID is fine). Change the bundle identifier if it collides.
4. Build & run on your device (⌘R). On the iPhone, enable Developer Mode and trust the developer certificate on first launch.

🔑 Gemini API key

The app never ships a key. Add yours in Settings → API Key — it's stored only in the iOS Keychain, on your device. Get a free key at https://aistudio.google.com/apikey and keep billing disabled to stay on the free tier.

(Optional: you can pre-seed a key via a gitignored Secrets.xcconfig — see Secrets.example.xcconfig.)

🔒 Privacy

All data lives locally via SwiftData. The only outbound network request is the single meal-photo (and drink) analysis to Gemini. No accounts, no analytics, no servers.

📝 Notes

A personal project, built for one device via free-Apple-ID sideloading — not on the App Store. Not affiliated with Google or Apple.