Requirements: Basic Todo App

Feature Overview

A simple, intuitive todo application that allows users to manage their daily tasks with basic CRUD operations and task status tracking.

User Stories

Epic: Task Management

**As a user, I want to manage my tasks so that I can stay organized and productive.**

US-001: Add Tasks

• **As a user, I want to add new tasks so that I can track things I need to do**
• **Acceptance Criteria:**
• I can enter a task description
• Tasks are saved and displayed in my list
• Empty tasks cannot be added
• Tasks have a default "pending" status

US-002: View Tasks

• **As a user, I want to view my task list so that I can see what needs to be done**
• **Acceptance Criteria:**
• All tasks are displayed in a clear list format
• Tasks show description and current status
• The list updates in real-time when tasks are added/modified

US-003: Mark Tasks Complete

• **As a user, I want to mark tasks as complete so that I can track my progress**
• **Acceptance Criteria:**
• I can toggle task status between pending and completed
• Completed tasks are visually distinguished (strikethrough, different color)
• Status changes persist across sessions

US-004: Edit Tasks

• **As a user, I want to edit task descriptions so that I can correct mistakes or update details**
• **Acceptance Criteria:**
• I can modify existing task descriptions
• Changes are saved automatically or with confirmation
• Original task cannot be lost during editing

US-005: Delete Tasks

• **As a user, I want to delete tasks so that I can remove items I no longer need**
• **Acceptance Criteria:**
• I can remove individual tasks from my list
• Deletion is confirmed to prevent accidents
• Deleted tasks are permanently removed

Functional Requirements

P0 (Must Have)

• **REQ-001:** Add new tasks with text descriptions
• **REQ-002:** Display all tasks in a list view
• **REQ-003:** Mark tasks as complete/incomplete
• **REQ-004:** Delete individual tasks
• **REQ-005:** Data persistence across browser sessions

P1 (Should Have)

• **REQ-006:** Edit existing task descriptions
• **REQ-007:** Visual differentiation between completed and pending tasks
• **REQ-008:** Basic input validation (no empty tasks)

P2 (Nice to Have)

• **REQ-009:** Task counter (total/completed)
• **REQ-010:** Clear all completed tasks
• **REQ-011:** Basic keyboard shortcuts (Enter to add, Escape to cancel)

Non-Functional Requirements

Performance

• App should load within 2 seconds
• Task operations should be instant (<100ms response time)

Usability

• Simple, clean interface requiring no training
• Mobile-responsive design
• Accessible keyboard navigation

Reliability

• Data should persist in browser local storage
• Graceful handling of storage quota exceeded
• No data loss during normal operations

Technical Constraints

• Must work in modern browsers (Chrome 90+, Firefox 88+, Safari 14+)
• Client-side only application (no backend required)
• Use browser local storage for persistence
• Responsive design for mobile devices

Assumptions

• Users will primarily use the app on a single device
• Tasks are personal and don't need to be shared
• Internet connectivity not required after initial load
• Users understand basic web application interactions

Out of Scope

The following features are explicitly **not** included in this basic version:

• User authentication/accounts
• Task categories or tags
• Due dates or reminders
• Task priorities
• Multi-user collaboration
• Cloud synchronization
• Mobile app (native)
• Bulk operations
• Task search/filtering
• Data export/import

Success Metrics

• **Functional:** All P0 requirements implemented and working
• **Usability:** User can add, complete, and delete a task within 30 seconds
• **Technical:** App loads and functions offline after first visit
• **Quality:** Zero critical bugs, graceful error handling for edge cases

Dependencies

• Modern web browser with local storage support
• HTML5, CSS3, JavaScript (ES6+)
• No external libraries or frameworks required for basic version

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**Review Status:** Ready for review **Next Phase:** Design (pending approval)