Prophit

A personal spending prediction app for 20-somethings. Prophit connects to your bank data, pulls in external signals like weather and local events, and uses a council of LLMs to generate probabilistic daily spending forecasts — so you can actually see where your money's going before it's gone.

Built at HackEurope — Monzo track.

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Features

Daily Predictions (Home)

• Weather-aware spending predictions for Dublin, IE
• Probability bars for predicted spend categories (lunch, coffee, drinks, transport)
• Live week-ahead calendar generated by multi-LLM consensus (Claude + Gemini + GPT-4o Mini)
• Morning Briefing widget with daily voice playback

Long Horizon Insights

• Job quit runway — circular progress ring showing how long you can survive without income (powered by /get_runway API)
• Seasonal spending comparison (winter vs summer)
• Monthly spend trajectory with projection line graph
• Weekly recap with AI accuracy score

Spending History & Patterns

• Week / Month / Year toggle
• This week vs last week comparison bars
• Category breakdown donut chart
• Unusual spike alerts with merchant details

Scenario Simulator

• "What if I quit my job?" — runway slider
• "Cut eating out by 50%" — savings calculator
• "Move to a cheaper area" — rent comparison
• AI-generated budget tips from real spending patterns (via /get_tips)

Arena — Blockchain-Staked Social Savings

Create or join competitive savings arenas with friends, backed by real SOL stakes on the Solana devnet.

Arena Modes:

• Budget Guardian — Stay under your spending target. Lowest spender under budget wins.
• Vice Streak — Avoid vice categories (coffee, fast food, alcohol, takeaway, shopping, gambling). Last one standing wins.
• Savings Sprint — First to hit their savings target wins the prize pool. Auto-settles when a member crosses the line.

Arena Flow:

1. Create an arena: set a name, pick a mode, set a target amount, choose SOL stake, set end date
2. Share a 6-digit join code with friends
3. Members' spending is synced in real-time via Supabase
4. Winner is determined automatically at the end date (or early for Savings Sprint)
5. SOL prize pool is paid out via on-chain Solana transaction

Blockchain Details:

• Per-user Solana wallets generated and stored locally (AsyncStorage keypair)
• New users receive an automatic 0.15 SOL airdrop to get started
• Arena escrow accounts using Program Derived Addresses (PDAs)
• Transactions verifiable on Solana Explorer
• Smart contract handles stake collection, escrow, and winner payout

Morning Briefing

• Daily voice briefing generated by ElevenLabs TTS (Rachel voice, eleven_turbo_v2_5 model)
• Compact widget card with weather, top prediction, and a nudge
• Play/pause controls with animated sound wave
• Time-of-day greeting, dynamic spending context

AI Chat — "The Prophit"

• Conversational financial assistant powered by Groq (Llama 3.3-70B)
• Voice input via Groq Whisper API (speech-to-text)
• Text-to-speech output toggle (ElevenLabs)
• Aware of your current spending patterns and predictions
• Context-aware nudges and budget advice
• Maintains 20-message conversation history

Pro Tier (Stripe)

• Free tier with core predictions
• Pro tier at €1.99/month with 7-day free trial
• Stripe card payment flow (Apple Pay / Google Pay ready)
• Pro unlocks: full spending history, weekly recap, scenario simulator, voice briefings, AI chat

Onboarding

• Bank selection (Monzo, Revolut, AIB, Bank of Ireland, Bank of Scotland)
• Upload bank statement (JSON, CSV, PDF) or use demo data
• Guided connect flow with progress steps
• Auto-parses transactions and seeds the app

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Tech Stack

Frontend

Layer	Technology
Framework	React Native + Expo (SDK 54)
Language	TypeScript
Navigation	Expo Router (file-based)
Charts	react-native-chart-kit + react-native-svg
Audio	expo-av (ElevenLabs TTS playback)
Auth & DB	Supabase (auth, realtime, CRUD)
Blockchain	@solana/web3.js (Solana devnet)
Payments	@stripe/stripe-react-native
File handling	expo-document-picker + expo-file-system
Local storage	@react-native-async-storage/async-storage

Backend

Layer	Technology
Runtime	Python (FastAPI + Gradio)
LLMs	Claude Haiku 4.5, Gemini 2.5 Flash Lite, GPT-4o Mini
Deployment	Vercel
Voice	ElevenLabs TTS API

AI / Voice

Service	Model	Used for
Anthropic	Claude Haiku 4.5	Transaction analysis, consensus synthesis
Google	Gemini 2.5 Flash Lite	Parallel transaction analysis
OpenAI	GPT-4o Mini	Spending pattern detection
Groq	Llama 3.3-70B	Chat assistant responses
Groq	Whisper Large v3	Voice-to-text input
ElevenLabs	eleven_turbo_v2_5 (Rachel)	Morning briefing TTS

Supabase

Resource	Purpose
users table	User profiles, username, avatar
arenas table	Arena config, mode, targets, stakes, status
arena_members table	Member spend tracking, last synced
arena_bets table	Bet records and outcomes
Auth	Email/password sign up and sign in
Realtime	Live arena updates via Postgres subscriptions

Solana

Component	Detail
Network	Devnet
Wallet	Per-user keypair, generated on onboarding
Airdrop	0.15 SOL auto-airdrop to new wallets
Escrow	PDAs per arena for trustless stake holding
Settlement	On-chain payout to winner's wallet
Explorer	Solana Explorer links for every transaction

Design System (Monzo-inspired)

Token	Value
Primary / CTA	Hot Coral #FF4F40
Headers / Text	Deep Navy #112231
Background	Soft White #F2F8F3
Accent	Deep Teal #004E60
Accent	Neon Yellow #C3FF34
Accent	Mid Orange #FE8B18
Corner radius	24pt+
Font	Inter / system sans-serif

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Project Structure

prophit/
├── frontend/                      # React Native / Expo app
│   ├── app/
│   │   ├── (tabs)/                # Bottom-tab screens
│   │   │   ├── index.tsx          # Home — daily predictions
│   │   │   ├── insights.tsx       # Long horizon insights
│   │   │   ├── history.tsx        # Spending history & patterns
│   │   │   ├── simulator.tsx      # Scenario simulator
│   │   │   ├── arena.tsx          # Social savings arenas
│   │   │   └── profile.tsx        # User profile & stats
│   │   ├── briefing.tsx           # Morning briefing card
│   │   ├── chat.tsx               # AI chat assistant
│   │   ├── onboarding.tsx         # Bank connect flow
│   │   ├── login.tsx              # Auth (sign in / sign up)
│   │   ├── upgrade.tsx            # Stripe Pro upgrade
│   │   ├── add-transaction.tsx    # Manual transaction entry
│   │   ├── arena-create.tsx       # Create arena
│   │   ├── arena-join.tsx         # Join arena by code
│   │   ├── arena-detail.tsx       # Arena detail & member spending
│   │   └── arena-results.tsx      # Arena results & Solana payout
│   ├── services/
│   │   ├── backendApi.ts          # Gradio API client
│   │   ├── chatService.ts         # Groq LLM chat service
│   │   ├── ttsService.ts          # ElevenLabs TTS service
│   │   ├── voiceService.ts        # Groq Whisper STT service
│   │   ├── transactionService.ts  # Transaction CRUD
│   │   ├── transactionSyncService.ts  # Arena spend syncing
│   │   ├── arenaSettlementService.ts  # Arena winner logic
│   │   ├── arenaSyncService.ts    # Real-time arena sync
│   │   └── solana/
│   │       └── solanaService.ts   # Solana wallet & escrow
│   ├── contexts/
│   │   ├── ArenaContext.tsx       # Supabase arena state & auth
│   │   ├── SolanaContext.tsx      # Solana wallet state
│   │   └── UserDataContext.tsx    # User transactions & predictions
│   ├── components/                # Reusable UI components
│   └── package.json
├── test-backend/                  # FastAPI + Gradio backend (local dev)
│   ├── main.py
│   ├── ui.py
│   └── requirements.txt
└── README.md

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Getting Started

Prerequisites

• Node.js 18+
• Expo CLI (npm install -g expo-cli)
• iOS Simulator / Android Emulator or Expo Go on device

Frontend Setup

cd frontend
npm install

Create a .env file in frontend/:

EXPO_PUBLIC_SUPABASE_URL=your_supabase_url
EXPO_PUBLIC_SUPABASE_ANON_KEY=your_supabase_anon_key
EXPO_PUBLIC_ELEVENLABS_API_KEY=your_elevenlabs_key
EXPO_PUBLIC_GROQ_API_KEY=your_groq_key

Start the app:

npm start        # Expo dev server
npm run ios      # iOS simulator
npm run android  # Android emulator

Backend Setup (local dev only)

cd test-backend
python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt

Create a .env file in test-backend/:

ANTHROPIC_API_KEY=your_anthropic_key
GEMINI_API_KEY=your_gemini_key
OPENAI_API_KEY=your_openai_key

Run the Gradio UI:

python ui.py

Or run the FastAPI server:

uvicorn main:app --reload --port 8001

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Backend API

Production base URL: https://prophit-ashy.vercel.app

All endpoints follow the Gradio async pattern:

// Step 1: Submit
const { event_id } = await fetch('/gradio_api/call/{endpoint}', {
  method: 'POST',
  body: JSON.stringify({ data: [...args] }),
}).then(r => r.json());

// Step 2: Poll for result (SSE stream)
const text = await fetch(`/gradio_api/call/{endpoint}/${event_id}`).then(r => r.text());
const result = JSON.parse(text.split('\n').find(l => l.startsWith('data: ')).slice(6));

Endpoints

Endpoint	Input	Output	Used for
/analyse_uploaded	Transaction file (JSON/CSV/PDF/TXT)	3× markdown analyses (Claude, Gemini, OpenAI)	Insights, History screens
/calendar_uploaded	Transaction file	Week-ahead calendar markdown + JSON predictions	Home screen predictions
/get_tips	Spending pattern text	AI budget tips (markdown)	Simulator, Chat
/get_runway	Financial summary text	Income runway analysis (markdown)	Insights runway ring
/_runway_summary_from_file	Transaction file	Financial summary text	Feed into /get_runway

Calendar JSON shape

{
  "week_start": "2026-03-01",
  "daily_predictions": [
    {
      "date": "2026-03-02",
      "day": "Monday",
      "predictions": [
        {
          "behavior": "Coffee",
          "likelihood": 83,
          "avg_spend": 5.50,
          "agreed_by": ["claude", "openai"]
        }
      ]
    }
  ]
}

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How the Multi-LLM Engine Works

1. File parsing — transactions enriched with day_of_week
2. Parallel analysis — Claude, Gemini, and GPT-4o Mini each analyse the full history simultaneously
3. Pattern detection — each model identifies recurring spending behaviours by day and category
4. Consensus calendar — Claude synthesises all three outputs into a single week-ahead calendar
5. Deduplication — duplicate merchants merged, most accurate predictions surfaced

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How the Arena Settlement Works

1. Creator sets arena mode, target, stake amount (SOL), and end date
2. All members' Solana wallets fund the escrow PDA on creation/join
3. During the arena, member transactions are synced to Supabase in real-time
4. At end date (or early trigger for Savings Sprint), the settlement service runs:
   • Budget Guardian: member with lowest spend under target wins
   • Vice Streak: member who avoided vice categories longest wins
   • Savings Sprint: first member to reach savings target wins (auto-settles immediately)
5. Winner's wallet receives the full SOL prize pool via on-chain transaction
6. Solana Explorer link displayed in arena results screen

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Environment Variables

Variable	Where	Purpose
EXPO_PUBLIC_SUPABASE_URL	frontend/.env	Supabase project URL
EXPO_PUBLIC_SUPABASE_ANON_KEY	frontend/.env	Supabase anon key
EXPO_PUBLIC_ELEVENLABS_API_KEY	frontend/.env	ElevenLabs TTS voice briefings
EXPO_PUBLIC_GROQ_API_KEY	frontend/.env	Groq (chat LLM + Whisper STT)
ANTHROPIC_API_KEY	test-backend/.env	Claude API
GEMINI_API_KEY	test-backend/.env	Gemini API
OPENAI_API_KEY	test-backend/.env	OpenAI API

Never commit .env files — they are in .gitignore.