Dialed — Espresso Journal

A mobile-first PWA for tracking and perfecting espresso extractions. Built with Next.js, Supabase, and Gemini AI.

Live at https://opti-brew.vercel.app

Features

• Shot logging — dose, yield, extraction time, grind setting, temperature, brew method
• Extraction timer — requestAnimationFrame-based, never throttled on iOS
• BaristaBrain — AI-powered per-shot coaching via Gemini; strict Head Barista persona with espresso troubleshooting hierarchy
• Bag scan — photograph a coffee bag, Gemini Vision extracts roaster/origin/roast details and generates first-shot startup params
• Bean inventory — track bags, roasters, origins, price, weight; duplicate detection with fuzzy matching
• Community Prep Method — aggregates shot stats across all users to surface the best brew method per bean
• VFM Index — ranks beans by score-per-shekel (value for money)
• VFM Leaderboard — medal-ranked leaderboard across your whole bag history
• Analytics — scatter chart of extraction time vs. score to visualise dial-in progress
• Auth — Google OAuth (PKCE) via Supabase; RLS enforces owner-only writes, community-wide reads
• PWA — installable on iOS and Android

Stack

Layer	Choice
Framework	Next.js 16 (App Router)
Language	TypeScript 5
Styling	Tailwind CSS v4
Database	Supabase (PostgreSQL + RLS)
Auth	Supabase Auth — Google OAuth (PKCE)
AI	Google Gemini (gemini-2.5-flash, fallback gemini-1.5-flash)
Charts	Recharts
PWA	@ducanh2912/next-pwa

Multi-Agent Architecture

All AI logic lives in lib/agents/. Each agent owns exactly one domain:

Agent	Domain
DiagnosticsAgent	Per-shot barista coaching
VisionAgent	Photo OCR — bag image → structured JSON
BrewRecommendationAgent	First-shot startup params from bean details
CommunityAnalyticsAgent	Best brew method per bean from shot statistics
Orchestrator	Routes and chains agent calls

Getting Started

1. Install dependencies

npm install

2. Set environment variables

Create .env.local in the project root:

NEXT_PUBLIC_SUPABASE_URL=your_supabase_url
NEXT_PUBLIC_SUPABASE_ANON_KEY=your_supabase_anon_key
GEMINI_API_KEY=your_gemini_api_key

3. Run the dev server

npm run dev

Open http://localhost:3000.

Deployment

Deployed on Vercel. Env vars are managed via the Vercel CLI:

npx vercel env add GEMINI_API_KEY production
npx vercel --prod --yes

PWA Icons

Drop icon-192.png and icon-512.png into /public to complete the PWA install experience.