🏋️ PrismCoach

Military-grade AI fitness coach. iPhone · iPad · Apple Watch app. Tracks recovery, predicts fatigue, generates training programs, and coaches you in real-time — in 23 languages. Works fully offline with an on-device AI model (Pro+). Standalone repo: forge-watch.

🔋 Body Battery

Your primary readiness score — a composite of overnight HRV, resting heart rate trend, sleep quality, and training load accumulated over the past 7 days.

• Scoring — 0–100. ≥ 75 = Fresh (green), 50–74 = Moderate (yellow), 25–49 = Fatigued (orange), < 25 = Depleted (red).
• HealthKit integration — reads passive overnight HRV captured by Apple Watch. No manual input required.
• Baseline recalibration — body battery recomputes its rolling baseline weekly so a well-trained athlete and a beginner see correctly normalised scores.
• ATR Engine — Adaptive Training Readiness synthesises 7+ biometric signals into a single readiness index. Accounts for acute (last 3 days) vs. chronic (28-day) load ratio.

💪 Muscle Recovery Map

Per-muscle fatigue tracking across 14 anatomical regions using a parametric body-map canvas rendered in SwiftUI.

• 14 muscle groups — Chest, Anterior/Lateral/Posterior Delts, Biceps, Triceps, Traps, Lats, Core, Lower Back, Glutes, Quads, Hamstrings, Calves.
• Charge model — each muscle decays from 100% to 0% over 48–96 hours post-workout depending on exercise volume and RPE. Recovery follows a sigmoidal curve (not linear).
• Front / Back toggle — tap to flip the silhouette. iOS uses a segmented picker; watchOS shows both views as swipe tabs.
• Color coding — ≥ 75% green, 50–75% yellow, 25–50% orange, < 25% red.
• Training highlights — muscles targeted by today’s program pulse orange on the canvas.

📋 Training Programs

Six science-based periodisation templates covering all major training goals.

• AI-generated programs (Elite) — describe your goal and constraints; PrismCoach generates a fully custom multi-week block using Prism 8B or Claude Sonnet.
• JSON Program Generator — programs are represented as typed Swift models; the engine can generate a full 8-week program in < 500 ms on-device.
• Watch sync — active program caches to Apple Watch for offline coaching (< 100 KB payload).

🍎 Nutrition Engine

NLP-powered meal logger — describe food in plain language, get macros.

• NLP meal logging — type or dictate “2 eggs, toast with butter, black coffee” and the engine parses food entities, quantities, and units using regex + Claude Haiku.
• Macro targets — calculated from body weight, goal (cut/bulk/maintain), and activity level. Adjusts daily based on training load.
• Caloric tracking — running daily total with breakdown (protein / carbs / fat / fibre / water).
• Nutrient density scoring — flags micronutrient gaps based on logged foods.
• Hydration reminders — adaptive push notifications based on workout sweat rate estimate.

🤖 AI Coach

Conversational coaching that knows your recovery state, last session, and program context.

• Free tier — no AI (static program templates only).
• Pro — Prism 1.7B on-device — runs via llama.cpp with Metal acceleration. Zero network, fully private. Answers questions about your training, suggests form corrections, adjusts today’s volume based on readiness.
• Elite — Prism 1.7B → 8B → Claude Sonnet cascade — on-device first; escalates to Prism inference server (8B) for complex questions; falls back to Claude Sonnet for nuanced coaching.
• Context window — ForgeMemoryStore injects last 3 sessions, active program week, current muscle charges, and body battery score into every prompt.
• Voice output — AI replies are spoken via ForgeTTSEngine: Synalux cloud TTS (MP3, 24 kHz) with AVSpeechSynthesizer offline fallback. Six coaching tones: Friendly, Calm, Excited, Precise, Empathetic, Hopeful.
• Proactive coaching — ProactiveCoachEngine surfaces unprompted insights (e.g. “Your HRV dropped 15% — consider reducing intensity today”) based on 7 trigger types.

⌚ Apple Watch App

Full companion app — not just notifications. Independent session tracking on wrist.

• 5 Watch tabs — Dashboard (Body Battery), Muscle Map, Workout Logger, CNS Tap Test, Settings.
• Workout session — log sets (exercise, weight, reps, RPE) directly from wrist. 90-second rest timer with haptic countdown.
• CNS Tap Test — 10-second pre-workout fast-tap test. Measures taps/sec; flags neuromuscular fatigue if below personal baseline.
• Haptic Pace-Keeper — rhythmic haptics during AMRAP/EMOM circuits.
• Phone sync — WatchConnectivity bridge pushes batteries, body battery, and feature flags bidirectionally in real time.
• Auto-Set Detection — accelerometer + gyroscope recognise set start/stop and classify exercise type. Disable to save watch battery.
• Velocity-Based Training — wrist-mounted bar velocity estimation using CoreMotion. Flags neuromuscular fatigue when bar speed drops > 15%.

🧬 Femme Engine

Cycle-phase-aware metric adjustments for female athletes (opt-in).

• 4 phases — Menstrual, Follicular, Ovulatory, Luteal.
• Training adjustments — volume, intensity targets, and RPE recommendations shift per phase based on published research on hormonal effects on strength and recovery.
• Body battery correction — basal body temperature and heart rate variability baselines are adjusted by phase to prevent false fatigue flags mid-cycle.
• Privacy — cycle data never leaves the device (CoreData, no sync).

🧠 Sleep & HRV

Overnight recovery science running silently in the background.

• HRV capture — passive HealthKit queries for overnight HRV samples. No active measurement required.
• Sleep stage analysis — reads Apple’s sleep stage data (awake/core/deep/REM) to score sleep quality.
• Training loop — SleepTrainingLoop correlates prior day’s load with next-morning HRV to build a personal stress–recovery model over time.
• Body battery baseline — rolling 28-day median HRV used as personal reference; deviations drive the battery score.

🔊 Voice & TTS

AI coaching spoken aloud in your language.

• Synalux TTS — cloud MP3 synthesis at 24 kHz/96 kbps mono via Synalux portal. 6 coaching tones.
• Offline fallback — AVSpeechSynthesizer with auto-selection of highest available voice quality (premium ≥ enhanced ≥ default). Works in all 23 supported languages.
• Music ducking — ForgeTTSEngine automatically ducks Apple Music / Spotify during coaching speech and restores volume after.
• Auto-tone inference — message content is scanned for emotional keywords (PR, fatigue, injury, comeback, etc.) and the appropriate tone is selected automatically.
• Voice commands — VoiceCommandEngine handles hands-free set logging (“log 100kg 5 reps RPE 8”) and navigation (“show my muscle map”) via Speech framework.

🌍 Languages

23 supported languages via Apple’s speech stack + Synalux TTS.

• BCP-47 language codes — per-user language preference stored in LanguageStore; used for TTS voice selection and AI coach system prompt locale.
• AI coaching — prompts are written in the user’s selected language. Claude and Prism models handle all 23 languages.
• 23 languages — English, Spanish, French, Portuguese, German, Italian, Dutch, Polish, Russian, Ukrainian, Romanian, Czech, Hungarian, Swedish, Norwegian, Finnish, Japanese, Korean, Mandarin, Arabic, Hindi, Turkish, Hebrew.

🏗️ Architecture

• PrismCoachCore — shared Swift Package (SPM) containing all engines, models, and business logic. Consumed by the iOS app, Mac Catalyst app, and watchOS extension.
• llama.cpp (Metal) — on-device inference for Prism 1.7B GGUF model via a local SPM package (_llama_cpp_local). iOS/macOS only; excluded from watchOS at compile time.
• WatchConnectivity bridge — WatchBridge syncs muscle batteries, body battery, and feature flags bidirectionally between iPhone and Watch in real time.
• CloudKit sync — CloudKitSyncEngine replicates workout history and user profile across devices using CKRecord change tokens with conflict resolution.
• HealthKit — reads HRV, sleep stages, resting HR, active energy, and workout samples. Writes workout session summaries.
• Siri Intents — LogWorkoutIntent, GetBodyBatteryIntent, StartRestTimerIntent for Shortcuts integration.

🔒 Privacy

• Local-first — all biometric data stays on-device. No analytics SDK. No third-party crash reporting.
• HealthKit — read-only access except workout session writes. Described in App Store privacy label.
• AI prompts — Pro tier never sends data to any server. Elite tier sends anonymised training context to Prism inference server (no PII, no HealthKit data).
• Subscription check — email posted via HTTPS to api.prismcoach.app/subscription/check. Email stored in Keychain with 24-hour TTL and 48-hour grace window.
• Cycle data — Femme Engine data is CoreData-only, never synced.

💳 Plans

Subscribe at prismcoach.app/subscribe  — Stripe-backed web checkout. No in-app purchase required.

🧪 Tests

904 automated tests covering all core engines — ATR, Body Battery, Muscle Battery, AI routing, Nutrition, Sleep, CNS, Siri Intents, Subscription, CloudKit, VBT, Voice commands, and more.

watchOS build:    ✅ BUILD SUCCEEDED
iOS tests (904):  ✅ 904/904 passed, 0 failures