bill/.kiro/specs/personal-billing-app/requirements.md

Requirements Document

Introduction

This document outlines the requirements for a personal billing application that automatically captures transaction data from Android notifications and provides comprehensive expense tracking with cloud synchronization. The app will be built using Vue.js frontend, Node.js backend, and Capacitor.js for Android integration, featuring a warm modern design with neumorphic elements.

Requirements

Requirement 1

User Story: As a user, I want the app to automatically read payment notifications from apps like Alipay and WeChat, so that I can capture transactions without manual entry.

Acceptance Criteria

1. WHEN a payment notification is received from supported apps THEN the system SHALL extract transaction details (amount, merchant, payment type)
2. WHEN transaction data is extracted THEN the system SHALL present a pre-filled confirmation dialog to the user
3. WHEN the user confirms the transaction THEN the system SHALL save it to the local database
4. IF the notification format is unrecognized THEN the system SHALL log the notification for future pattern analysis
5. WHEN the app starts THEN the system SHALL request notification access permissions from Android

Requirement 2

User Story: As a user, I want to manually add, edit, and delete billing records, so that I can maintain complete control over my financial data.

Acceptance Criteria

1. WHEN the user taps the floating action button THEN the system SHALL display an add transaction form
2. WHEN creating a transaction THEN the system SHALL require amount, category, and date fields
3. WHEN editing a transaction THEN the system SHALL pre-populate the form with existing data
4. WHEN deleting a transaction THEN the system SHALL request confirmation before removal
5. WHEN saving a transaction THEN the system SHALL validate all required fields are completed
6. WHEN the amount field is focused THEN the system SHALL display a numeric keypad
7. WHEN selecting a category THEN the system SHALL display icon-based category selection

Requirement 3

User Story: As a user, I want to search and filter my transactions, so that I can quickly find specific records.

Acceptance Criteria

1. WHEN the user enters text in the search bar THEN the system SHALL filter transactions by merchant name and notes
2. WHEN the user applies date filters THEN the system SHALL show only transactions within the selected date range
3. WHEN the user selects category filters THEN the system SHALL display only transactions from selected categories
4. WHEN the user selects account filters THEN the system SHALL show only transactions from selected payment methods
5. WHEN multiple filters are applied THEN the system SHALL combine them using AND logic

Requirement 4

User Story: As a user, I want my data synchronized across devices, so that I can access my billing information anywhere.

Acceptance Criteria

1. WHEN the user registers THEN the system SHALL create a secure user account with JWT authentication
2. WHEN the user logs in THEN the system SHALL authenticate credentials and provide access token
3. WHEN network is available THEN the system SHALL automatically sync local changes to the server
4. WHEN network is unavailable THEN the system SHALL queue changes for later synchronization
5. WHEN conflicts occur during sync THEN the system SHALL prioritize server data and notify the user
6. WHEN the app starts THEN the system SHALL check for server updates and sync if needed

Requirement 5

User Story: As a user, I want to view spending trends and analysis, so that I can understand my financial patterns.

Acceptance Criteria

1. WHEN viewing the analysis page THEN the system SHALL display spending by category in a pie chart
2. WHEN selecting a time period THEN the system SHALL show spending trends in a line chart
3. WHEN viewing monthly summary THEN the system SHALL display total income, expenses, and balance
4. WHEN viewing category breakdown THEN the system SHALL show percentage and amount for each category
5. WHEN no data exists for selected period THEN the system SHALL display an appropriate empty state message

Requirement 6

User Story: As a user, I want an intuitive and visually appealing interface, so that managing my finances is enjoyable.

Acceptance Criteria

1. WHEN the app loads THEN the system SHALL display transactions in card format with category icons
2. WHEN interacting with buttons THEN the system SHALL provide smooth animations and visual feedback
3. WHEN viewing the interface THEN the system SHALL use the warm modern color scheme (orange primary, gray background)
4. WHEN using forms THEN the system SHALL apply neumorphic design elements to inputs and buttons
5. WHEN displaying amounts THEN the system SHALL use appropriate colors (red for expenses, green for income)
6. WHEN the interface loads THEN the system SHALL use proper typography hierarchy with Inter or Poppins font

Requirement 7

User Story: As a user, I want the app to work offline, so that I can manage my finances without internet connectivity.

Acceptance Criteria

1. WHEN network is unavailable THEN the system SHALL continue to function with local data
2. WHEN adding transactions offline THEN the system SHALL save them to local SQLite database
3. WHEN network becomes available THEN the system SHALL automatically sync pending changes
4. WHEN viewing data offline THEN the system SHALL display the most recent synchronized data
5. WHEN sync fails THEN the system SHALL retry automatically with exponential backoff

Requirement 8

User Story: As a user, I want to manage transaction categories and payment accounts, so that I can organize my finances according to my preferences.

Acceptance Criteria

1. WHEN setting up the app THEN the system SHALL provide default categories (food, transport, shopping, entertainment)
2. WHEN the user creates a custom category THEN the system SHALL allow icon and color selection
3. WHEN managing payment accounts THEN the system SHALL support cash, Alipay, WeChat, and bank cards
4. WHEN adding a new account THEN the system SHALL require a name and allow icon selection
5. WHEN deleting a category with existing transactions THEN the system SHALL require reassignment or confirmation