SoleBook

Overview

I built SoleBook as an AI-assisted cash-discipline product for Sri Lankan sole proprietors and SMEs — not another generic ledger. The idea is simple: incoming money should be allocated before it is spent. The public surface is a multilingual Next.js site (English, Sinhala, Tamil) with a validated waitlist. Behind that sits a written handshake with Srijaya ERP so later product work can talk to a real shop system, not a fake bank.

We shipped the first working version in 24 hours at Cursor Buildathon Colombo 2026 (FinTech track, hosted with Seylan Bank). I was on team Reid Injection. We placed 4th in the track. The repo is the product artefact that continued after the arena.

Problem

Healthy revenue does not save a shop that treats the business account as a personal wallet. Owners pay bills when they notice them, skip tax set-asides, delay suppliers, and never grow a reserve. Generic accounting software reports what already happened. What these operators needed was a discipline system: named buckets, a reason to leave money untouched, and explanations a non-accountant can follow.

What I built

I designed the product around four allocation buckets — operations, obligations, reserves, and owner salary — so personal drawings are a planned line, not leftover cash. AI sits on top of those rules: pattern notes, allocation suggestions, which bills to pay first, and plain-language explanations instead of a spreadsheet dump.

The buildathon slice includes the marketing/waitlist app (duplicate-safe sign-ups, Supabase with a local fallback) and a documented SoleBook ↔ Srijaya contract: authenticated, idempotent payment routes and privacy-aware financial snapshots. A Financial Discipline Score was part of the demo: it scores behaviour (reserves, on-time obligations, sticking to the plan) rather than a closing balance.

Impact

The competition result was a placement, not a launch metric — 4th in FinTech among a large Colombo field. More useful for the portfolio: a Sri Lanka-first finance narrative grounded in a live ERP I already operate, plus localisation from day one. The 24-hour constraint forced a product brief I could keep shipping after the event.

Key features

• Allocation into operations, obligations, reserves, and owner salary
• AI insights, payment priority, and natural-language explanations
• Financial Discipline Score focused on habits, not vanity balances
• English / Sinhala / Tamil waitlist experience
• Duplicate-safe waitlist API with Supabase persistence
• Written ERP payment and snapshot contract for Srijaya

Technologies

Next.js, React, TypeScript, and Tailwind CSS for the product surface. Supabase for persistence. The buildathon demo also used Gemini for recommendations, with a custom rules engine so allocations stay deterministic even when the model is wrong. Cursor was the primary build environment.

My role

Product design, localisation, waitlist API, and the ERP integration spec. Reid Injection built and demoed together; I continued the product and repo after the first commits.