Kairos

A maternal cardiovascular health companion. Built for the Heart Health at Warp Speed track — turning pregnancy and postpartum care into a long-term heart-health intervention.

Internal planning notes live in docs/ and are gitignored. See those files for the full design, schema, prompts, and timeline.

Tech stack

• Mobile: React Native + Expo (managed workflow), TypeScript, Expo Router
• Backend: Supabase (auth + Postgres + RLS) and a small FastAPI service for rPPG video analysis
• AI: Google Gemini 2.0 Flash

Quick start

# 1. Install dependencies
npm install

# 2. Copy env template and fill in keys
cp .env.example .env.local
# then edit .env.local with your Supabase + Gemini values

# 3. Start the dev server
npx expo start

# 4. Open on a device
#   - iOS:     scan the QR code with the Expo Go app
#   - Android: scan with Expo Go or press 'a' for the emulator

Required environment variables (see .env.example):

Variable	Purpose
EXPO_PUBLIC_SUPABASE_URL	Supabase project URL
EXPO_PUBLIC_SUPABASE_ANON_KEY	Supabase publishable key
EXPO_PUBLIC_GEMINI_API_KEY	Google AI Studio key for Gemini
EXPO_PUBLIC_RPPG_API_URL	URL of the deployed FastAPI rPPG service

Project layout

app/             Expo Router screens
  (auth)/        Login + intake flow
  (app)/         Authenticated app
    alert/       KPIN red-flag + emergency screens
src/
  components/    Reusable UI primitives
  contexts/      Auth + UserData providers
  hooks/         useKpin, useMockHealthKit, useMoodStreak
  lib/           Pure logic (KPIN, mock data, prompts, formatters)
  services/      Supabase, Gemini, rPPG, PDF clients
  theme/         Design tokens
  types/         Shared TypeScript types
backend-rppg/    Python FastAPI service for rPPG video analysis
docs/            Planning docs (gitignored)

rPPG backend

The Python service lives in backend-rppg/ and is deployed independently to Render (free tier). Locally:

cd backend-rppg
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
uvicorn main:app --reload --port 8000

Team workflow

• All code, comments, and commit messages are in English.
• One small feature per commit. Format: type: short summary.
• Do not add Co-Authored-By lines to commits.
• Planning notes belong in docs/ (local only, gitignored).