Account Creation and Login: Allow users to create accounts, log in securely, and manage their profiles. Support various authentication methods (e.g., email/password, social login).
Profile Management: Enable users to update their profiles, including display names, profile pictures, and status messages.
User Presence: Show online/offline status and activity indicators for users.
Real-Time Messaging
One-on-One Messaging: Support real-time text messaging between two users, including sending, receiving, and displaying messages instantly.
Group Messaging: Allow users to create and participate in group chats with multiple users. Support features like adding/removing members and group naming.
Message Notifications: Provide notifications for new messages, including visual and audio alerts.
Message Features
Text Formatting: Support basic text formatting options like bold, italics, and underline.
Multimedia Sharing: Allow users to send and receive multimedia files such as images, videos, and audio clips.
Emojis and Stickers: Integrate emoji and sticker support for richer communication.
Message History
Chat History: Enable users to view and search through their past conversations and messages.
Message Synchronization: Ensure messages are synchronized across different devices and platforms used by the same user.
Privacy and Security
End-to-End Encryption: Implement end-to-end encryption to secure messages and ensure only intended recipients can read them.
Message Deletion: Allow users to delete messages from their chat history and optionally, from the recipient’s history as well.
User Interaction
Typing Indicators: Show when a user is typing a message in real-time.
Read Receipts: Provide information on whether a message has been read by the recipient.
Contact Management
Contacts List: Enable users to manage their contact list, including adding, removing, and searching for contacts.
Contact Requests: Support sending and receiving friend or contact requests.
Search and Filtering
Chat Search: Allow users to search for specific messages or conversations.
User Search: Provide functionality to search for other users or contacts.
Integration and APIs
Third-Party Integrations: Allow integration with third-party services like cloud storage or calendar applications.
APIs: Provide APIs for integration with other systems and platforms, including support for embedding chat functionalities.
Administrative Features
User Management: Provide admin tools for managing users, including moderation and banning features.
Analytics and Reporting: Include tools for monitoring chat activity, user engagement, and system performance.
Non-Functional Requirements
Performance
Response Time: Ensure low latency for message delivery and real-time interactions (e.g., under 1 second for message transmission).
Scalability: The system should handle a growing number of users and messages without performance degradation.
Reliability
Uptime: Ensure high system availability with minimal downtime (e.g., 99.9% uptime).
Error Handling: Implement robust error handling and recovery mechanisms to manage system failures and ensure continuity of service.
Security
Data Encryption: Encrypt all data transmissions and stored data to protect user privacy and data integrity.
Authentication and Authorization: Use secure methods for user authentication and authorization to protect user accounts and data.
Usability
User Interface: Design an intuitive and user-friendly interface that facilitates easy navigation and interaction for all user roles.
Accessibility: Ensure the application is accessible to users with disabilities, including support for screen readers and keyboard navigation.
Maintainability
Code Quality: Write high-quality, well-documented code to facilitate system maintenance, updates, and troubleshooting.
Documentation: Provide comprehensive documentation for users, administrators, and developers, including operational procedures and technical specifications.
Availability
Backup and Recovery: Implement regular data backups and establish procedures for data recovery in case of system failures or data loss.
Failover: Ensure the system has failover capabilities to switch to backup servers or systems if necessary.
Portability
Cross-Platform Compatibility: Ensure the application is compatible with various devices and operating systems, including desktop and mobile platforms.
Supportability
Technical Support: Provide mechanisms for obtaining technical support and resolving issues, including help desks, online resources, and customer service.
Error Reporting: Include functionality for reporting and tracking issues or bugs within the system.
