Documentation Overview

CrewSplit Documentation

Project: CrewSplit (formerly CrewLedger) Purpose: A deterministic, family-focused trip expense-splitting app built with Expo (iOS + Android).

Overview

CrewSplit is a subscription-free, glitch-proof trip expense splitter built on deterministic math, zero friction, and transparent UX.

Documentation Structure

• Settlements Summary - Settlement algorithm summary and decisions (MODELER)
• Settlements Architecture - Data model and design rationale (SYSTEM ARCHITECT)
• FX Schema Quick Reference - FX schema and queries (LOCAL DATA ENGINEER)
• Developer Guidelines - Coding standards and workflows

Quick Start

See AGENTS.md in the repo root for agent-specific responsibilities.

Tech Stack

• Framework: Expo (React Native)
• Routing: Expo Router
• Language: TypeScript
• Database: SQLite (expo-sqlite)
• ORM: Drizzle ORM
• State: Zustand
• Testing: Jest

Core Principles

1. Deterministic: Same inputs always produce same outputs
2. Local-first: Fully functional offline
3. Auditable: All computations traceable to source data
4. Zero friction: Minimal input, maximum clarity