AI Invoice Scanner for Freelancers

FinTechIntermediateJan 5, 2024

AI Invoice Scanner for Freelancers

Turn messy receipts into organized expense reports in seconds

The Problem

Freelancers spend 5+ hours monthly manually entering receipts and invoices into spreadsheets. They lose track of deductible expenses, miss tax deadlines, and waste time on tedious data entry instead of doing billable work.

The Solution

An AI-powered app that scans receipts/invoices via phone camera, automatically extracts key data (vendor, amount, date, category), and syncs to a dashboard for instant expense tracking and tax-ready reports.

Tech Stack

Frontend

Next.js 14ReactTailwind CSSFramer Motion

Backend

Next.js API RoutesOpenAI Vision APIPrisma ORM

Database

PostgreSQL (Supabase)Redis (caching)

APIs

OpenAI GPT-4 VisionStripe (payments)Resend (emails)

System Architecture

┌─────────────────────────────────────────────────────────────┐
│                        CLIENT                                │
│  ┌─────────────┐  ┌─────────────┐  ┌─────────────────────┐  │
│  │  Camera UI  │  │  Dashboard  │  │  Expense Reports    │  │
│  └──────┬──────┘  └──────┬──────┘  └──────────┬──────────┘  │
└─────────┼────────────────┼────────────────────┼─────────────┘
          │                │                    │
          ▼                ▼                    ▼
┌─────────────────────────────────────────────────────────────┐
│                      API LAYER                               │
│  ┌─────────────┐  ┌─────────────┐  ┌─────────────────────┐  │
│  │ /api/scan   │  │ /api/data   │  │ /api/export         │  │
│  │ (Vision AI) │  │ (CRUD ops)  │  │ (PDF/CSV gen)       │  │
│  └──────┬──────┘  └──────┬──────┘  └──────────┬──────────┘  │
└─────────┼────────────────┼────────────────────┼─────────────┘
          │                │                    │
          ▼                ▼                    ▼
┌─────────────────────────────────────────────────────────────┐
│                     DATA LAYER                               │
│  ┌─────────────────────────────────────────────────────────┐│
│  │               Supabase (PostgreSQL)                      ││
│  │  users │ invoices │ expenses │ categories │ reports     ││
│  └─────────────────────────────────────────────────────────┘│
└─────────────────────────────────────────────────────────────┘

Database Schema

-- Users table
CREATE TABLE users (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  email TEXT UNIQUE NOT NULL,
  name TEXT,
  plan TEXT DEFAULT 'free', -- free, pro, business
  created_at TIMESTAMPTZ DEFAULT now()
);

-- Invoices/Receipts table
CREATE TABLE invoices (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id UUID REFERENCES users(id),
  vendor_name TEXT NOT NULL,
  amount DECIMAL(10,2) NOT NULL,
  currency TEXT DEFAULT 'USD',
  date DATE NOT NULL,
  category TEXT,
  tax_deductible BOOLEAN DEFAULT false,
  image_url TEXT,
  raw_text TEXT, -- OCR extracted text
  created_at TIMESTAMPTZ DEFAULT now()
);

-- Categories table
CREATE TABLE categories (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id UUID REFERENCES users(id),
  name TEXT NOT NULL,
  icon TEXT,
  color TEXT
);

-- Monthly summaries (materialized view for dashboards)
CREATE MATERIALIZED VIEW monthly_summary AS
SELECT
  user_id,
  DATE_TRUNC('month', date) as month,
  category,
  SUM(amount) as total,
  COUNT(*) as count
FROM invoices
GROUP BY user_id, DATE_TRUNC('month', date), category;