# Build brief — a focused alternative to Splitwise

> **Verdict:** Partly, if you narrow it · **Buildability:** 49/100 · **Category:** Personal Finance
> **Source:** https://www.canitbevibecoded.com/splitwise
> Independent editorial assessment from Can It Be Vibe Coded? Not affiliated with, endorsed by, or derived from Splitwise. Verify current pricing and capabilities before acting.

## Context

**Splitwise** — Group expense tracker that splits bills and nags everyone until debts are settled. It currently costs $5/mo.

The ledger and the debt math are a solved problem; a link-shared DIY version covers a household or one trip in a focused implementation, no accounts needed. The gap is not code, it is adoption: Splitwise works because the whole group already has it installed, and nobody downloads your homebrew app for one weekend away. Build it for the people who share your fridge; for everyone else, the moat is other people's phones.

This brief describes a focused, single-operator replacement for the part of Splitwise that is genuinely reproducible. It is deliberately narrower than the product it replaces, and it says so in writing. Build the useful core; do not pretend to have rebuilt the rest.

## What you are building

Create link-shared groups, log expenses with flexible splits, and settle up via minimum cash flow debt simplification.

- Import transactions, categorize spending, and forecast cash flow privately.
- A responsive interface with real empty, loading, success, and error states.

## Requirements

### Non-functional

- Accessibility: semantic markup, labelled controls, visible focus, and reduced-motion support.
- Security: server-side secrets, validated input, and no credentials in the client bundle.
- Reliability: retries with backoff on external calls, and a clear failure state when a provider is down.
- Portability: the operator can export their data and leave without losing it.

## Implementation brief

Build a self-hosted group expense splitter: a single web app, no user accounts.

Stack: Node 22, Express, better-sqlite3, server-rendered EJS, htmx for interactivity. No build step, no SPA framework.

Features:
- Groups are created with one click and live at an unguessable URL (nanoid, 21 chars). The link is the auth model; say so plainly in the README.
- Members are names typed into the group, nothing more.
- Expenses: payer, amount, currency, date, note, category, and a split that can be equal, exact amounts, percentages, or shares.
- A balances view per group: each member's net position, plus a settle-up plan computed with minimum cash flow debt simplification.
- Reimbursements logged as a special expense type.
- Multi-currency: amounts stored in their own currency; a per-group manual rate table converts to the group's base currency. No external rate API.
- Edit and delete with a simple activity log.
- Export any group as CSV and JSON.

Storage: one SQLite file at ./data/app.db; path via .env. Ship a Dockerfile, a docker-compose.yml, and a README covering backups and reverse-proxy setup.

Out of scope, deliberately: accounts and OAuth, push notifications, receipt scanning, live exchange rates, payment integrations, native mobile apps. A PWA manifest so it installs to a home screen is the only concession.

## Delivery standard

- Inspect the repository first, then write a short implementation plan before writing code.
- Deliver the smallest complete end-to-end workflow first; every primary control must work against persisted data.
- Use real validation and storage; never substitute fake dashboards, decorative controls, hard-coded success states, or mock integrations.
- Include responsive layouts plus genuine empty, loading, success, validation, and failure states.
- Keep secrets server-side in environment variables, provide .env.example, and never commit credentials or user data.
- Add structured logs around every external call and return actionable errors without leaking sensitive details.
- Write unit tests for the core logic and one automated test of the main user journey.
- Finish with a README covering setup, architecture, data location, backups, tests, deployment, and known limitations.

## Acceptance criteria

- [ ] A clean install starts the app using only the README and .env.example.
- [ ] The primary journey works from first visit through saved result, reload, edit, export, and deletion where applicable.
- [ ] Invalid input, missing configuration, provider failure, and an empty database each have a usable state.
- [ ] The interface works at 390px and 1440px, is keyboard navigable, and shows visible focus on every control.
- [ ] Tests, type checking, linting, and a production build all pass with no ignored failures.
- [ ] No part of the interface implies a live integration, security guarantee, or scale capability that was not actually built and verified.

## Non-goals

Do not build these, and do not claim to have replaced them:

- Native iOS and Android apps, push reminders included.
- Your friends' existing accounts and muscle memory.
- Receipt scanning and itemized splits.
- Automatic currency conversion at live rates.
- Settle-up integrations with payment apps.

## What you still own after launch

- Run migrations, backups, restores, and dependency updates.
- Test the critical journey after every model, API, or hosting change.
- Monitor failures and fix the edge cases a first prompt will miss.
- Maintain every third-party integration as APIs and OAuth rules change.

## Risk

**High consequence.** Use this as a prototype or personal aid. Keep a qualified human and an established provider in the loop for consequential decisions.

Editorial confidence in this assessment: high. No reviewed project implementation is linked yet.

## Existing alternatives

Before building, compare these checked options:

- [Spliit](https://spliit.app) — Share a link, split, settle. No accounts, no ads. Use their instance or run your own
- [Tricount](https://tricount.com) — Free and huge in Europe; closed source and bunq-owned, new signups get a bunq account, and CSV export left with the old Premium
- [IHateMoney](https://ihatemoney.org) — Around since 2011, proudly boring, in declared maintenance mode; use their free instance or one docker run

## Prior art

Working open-source software you can read, fork, or borrow from before starting:

- [spliit](https://github.com/spliit-app/spliit) — open-source reference implementation worth stealing ideas from
- [minimum cash flow algorithm](https://www.geeksforgeeks.org/minimize-cash-flow-among-given-set-friends-borrowed-money/) — the debt simplification trick, explained

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Generated by [Can It Be Vibe Coded?](https://www.canitbevibecoded.com) · Full report: https://www.canitbevibecoded.com/splitwise