Yapplr - Twitter-like Social Media Platform

A complete Twitter-like social media platform built with modern web technologies. Features a clean, responsive design inspired by 2015 Twitter with comprehensive social features including yaps, reyaps, comments, likes, follow system, and privacy controls.

🚀 Features

Core Social Features

Yaps: Create text yaps (up to 256 characters) with optional images and videos
Multi-Media Posts: Upload up to 10 photos and videos per post with comprehensive media gallery support
Photo Library: Dedicated photo library showing all user images with slideshow navigation and theme-aware full-screen viewing
Reyaps: Reyap content with proper attribution in timeline feeds
Comments: Full-featured commenting system with dedicated comment screens, real-time count updates, auto-scroll to new comments, and reply functionality
Emoji Reactions: Rich reaction system with 6 emoji types (❤️ Heart, 👍 Like, 😂 Laugh, 😮 Surprised, 😢 Sad, 😡 Angry) for posts and comments
Interactive Reaction Picker: Hover-based emoji selection with smooth transitions from grayscale to color, colored SVG icons on hover, and background circle animations
Reaction Visual Effects: Emojis start in grayscale and transition to full color on hover with colored background circles and scale animations
Reaction Button Priority: Reaction button positioned first (leftmost) in action buttons for enhanced user engagement
Reaction Counts Display: Visual reaction count badges positioned between post content and actions to prevent layout shifts
Colored Reaction States: Selected reactions show colored SVG icons instead of filled black versions for clear visual feedback
Reaction Analytics: View detailed reaction breakdowns showing count per emoji type with pill-shaped badges
Comment Reactions: Full emoji reaction support for comments with same rich interaction as posts
Legacy Compatibility: Existing likes automatically converted to heart reactions during migration
Consistent Reaction Layout: Unified reaction experience across PostCard, FullScreenPhotoViewer, and FullScreenVideoViewer
Mentions: @username mention system with clickable links and real-time notifications
Hashtags: Complete #hashtag system with searchable tags, trending topics, clickable links, dedicated trending page with time periods, hashtag suggestions in post creation, and trending widgets
Link Previews: Automatic visual previews for URLs in posts with title, description, images, and error handling for broken links
Comment Replies: Reply to specific comments with automatic @username prefilling and smart reply context
Follow System: Follow/unfollow users with instant UI updates and optional follow approval system
Following/Followers Lists: Tabbed interface on profile pages showing Posts, Following (count), and Followers (count) with detailed user lists and navigation to their profiles
User Profiles: Complete profile management with bio, pronouns, tagline, birthday, and profile images
Profile Editing: Edit profile information including bio, pronouns, tagline, and birthday with real-time updates
Yap Sharing: Share yaps with social media integration and direct link copying
Content Management: Delete your own yaps, comments, and reyaps with confirmation dialogs
User Blocking: Block/unblock users with automatic unfollowing and content filtering
Settings Management: Dedicated settings page with blocklist management
Private Messaging: Send direct messages with text, photo, and video attachments
Message Conversations: Organized conversation threads with read status tracking and visual unread indicators
Messaging Privacy: Blocked users cannot send messages to each other
Message Notifications: Real-time unread message badges on Messages tab and conversation list
Enhanced Conversation UI: Bold text and background highlights for unread conversations
Real-time Notifications: Optimized notification system with platform-specific providers
- Web Frontend: SignalR WebSocket notifications for instant real-time delivery
- Mobile Apps: Firebase push notifications via API for battery-efficient delivery
- Clean Architecture: Frontend uses SignalR exclusively, API supports both for mobile compatibility
Comprehensive Notifications: Complete notification system for mentions, likes, reposts, follows, and comments with real-time red badge indicators
Comment Notifications: Instant notifications when someone comments on your posts with smart duplicate prevention (no double notifications when mentioned)
Follow Notifications: Get notified when someone starts following you with direct navigation to their profile
Follow Request System: Optional follow approval with request/accept/decline workflow and persistent status tracking
Reaction Notifications: Instant notifications when someone reacts to your posts or comments with emoji type display
Repost Notifications: Real-time alerts when someone reposts your content with direct post navigation
Smart Navigation: Click notifications to navigate directly to mentioned posts, comments, or user profiles with automatic scrolling and highlighting
Background Notifications: Push notifications work even when mobile apps are minimized or closed
Real-time Web Notifications: Instant SignalR WebSocket-based notifications for active web sessions
Fallback System: Automatic fallback between notification providers for reliability
Dark Mode: Complete dark theme support with user preferences and persistent storage

👥 Groups & Communities

Open Groups: Create and join public groups where anyone can participate
Group Management: Create groups with custom names, descriptions, and images
Group Discovery: Search and browse all available groups with pagination
Member Management: View group members with join dates and roles (Member, Moderator, Admin)
Group Posts: Post content directly in groups with automatic public visibility
Group Media Support: Full image and video support in group posts with proper URL generation
Public Group Content: All posts in groups are public regardless of user privacy settings
Group Ownership: Group creators become owners with full management permissions
Easy Joining: One-click join/leave functionality for all groups
Group Navigation: Dedicated group pages showing posts, members, and group information
User Group Lists: View all groups a user is a member of
Group Statistics: Real-time member counts and post counts for each group
Group Validation: Automatic validation of group membership before posting
Unique Group Names: Enforced unique group names across the platform
RESTful Group API: Complete REST API with 12 endpoints for all group operations

🛡️ Admin & Moderation System

Comprehensive Admin Dashboard: Full-featured admin interface with role-based access control
- Admin Roles: Support for Admin and Moderator roles with different permission levels
- Real-time Statistics: Live dashboard with user counts, content metrics, and moderation activity
- Quick Actions: Fast access to common moderation tasks and system management
🎯 User Trust Score System: Advanced behavioral scoring system for intelligent moderation
- Dynamic Trust Calculation: Real-time trust scores based on user behavior, activity, and community standing
- Trust-Based Moderation: Automatic content visibility and rate limiting based on user trust levels
- Smart Rate Limiting: Dynamic rate limits (0.25x to 2x) based on user trust scores
- Auto-Hide Low Trust Content: Content from very low-trust users (< 0.1) automatically hidden
- Moderation Priority Scoring: 1-5 priority levels for efficient moderation queue management
- Trust-Based Permissions: Action thresholds for posting, messaging, and reporting based on trust
- Comprehensive Analytics: Trust score statistics, distribution analysis, and trend tracking
- Admin Trust Management: Manual trust score adjustments with full audit trail
- Background Maintenance: Automated trust score recalculation and inactivity decay
AI-Powered Content Moderation: Intelligent automated content analysis and moderation
- Real-time Content Analysis: Automatic analysis of all posts and comments using AI sentiment analysis
- Pattern-Based Detection: Advanced pattern matching for NSFW content, violence, harassment, hate speech, and misinformation
- Risk Assessment: Automated risk scoring with configurable thresholds for review and auto-hiding
- Smart Tag Suggestions: AI-generated system tag recommendations with confidence scores
- Content Warning Detection: Automatic detection of sensitive content requiring warnings (NSFW, violence, spoilers)
- Violation Classification: Intelligent categorization of policy violations (harassment, hate speech, misinformation)
- Sentiment Analysis: Real-time sentiment scoring for content tone and emotional context
- Moderation Queue Integration: Flagged content automatically appears in admin moderation queue
- Configurable Automation: Adjustable settings for auto-apply tags, review thresholds, and auto-hiding
User Management: Complete user administration and moderation tools
- User Overview: Paginated user list with filtering by status (Active, Suspended, Banned, Shadow Banned) and role
- Comprehensive User Details: Click any username to view detailed user information including:
  - Profile Information: Complete user profile data, email verification status, member since date, last login details
  - Trust Score Analysis: Visual trust score display with factors breakdown and recent history
  - Rate Limiting Management: Configure user-specific rate limiting overrides and view current status
  - Activity Statistics: Comprehensive metrics including posts, comments, likes, followers, reports, and moderation actions
  - Moderation History: Recent administrative actions taken against the user with full audit trail
  - Role Management: Inline role editing with reason tracking and audit logging
  - User Actions: Suspend, ban, shadow ban, and unban users with comprehensive action buttons
- Rate Limiting Overrides: Disable or configure rate limiting settings for individual users
- Account Status: View user details including login history, IP addresses, and account metrics
Content Moderation: Advanced content management and moderation capabilities
- Post Management: View, hide, unhide, and delete posts with reason tracking and bulk actions
- Comment Management: Moderate comments with hide/unhide/delete functionality and bulk operations
- AI-Suggested Tags: Review and approve AI-generated system tag recommendations
- System Tags: Apply and manage system tags for content categorization and violation tracking
- Content Queue: Review flagged content with priority-based moderation workflow and AI insights
- Bulk Actions: Efficiently moderate multiple posts or comments simultaneously
System Tags: Flexible content labeling and violation tracking system
- Tag Categories: Organize tags by type (Violation, Warning, Information, etc.)
- Content Tagging: Apply system tags to posts and comments for tracking and filtering
- Tag Management: Create, edit, and manage system tags with descriptions and visibility settings
- AI Integration: Automatic tag suggestions based on content analysis
Audit Logging: Comprehensive activity tracking and accountability
- Action Logging: Track all admin and moderator actions with timestamps and reasons
- User Activity: Monitor user behavior and moderation history
- System Events: Log important system events and administrative changes
- AI Moderation Logs: Track AI analysis results and tag application history
Appeals System: User appeal workflow for moderation decisions
- Appeal Submission: Users can appeal suspensions, bans, and content removals
- Appeal Review: Admins and moderators can review and respond to user appeals
- Appeal Tracking: Track appeal status and resolution history
Analytics & Reporting: Detailed insights into platform health and moderation effectiveness
- User Growth: Track user registration, activity, and retention metrics
- Content Trends: Monitor post and comment creation, engagement, and moderation patterns
- Moderation Stats: Analyze moderation activity, response times, and effectiveness
- AI Performance: Monitor AI moderation accuracy and effectiveness metrics
- System Health: Monitor platform performance and identify potential issues

💳 Subscription System & Payment Gateways

Tiered Subscription Model: Flexible subscription system with multiple tiers and pricing options
- Subscription Tiers: Create and manage multiple subscription tiers with different features and pricing
- Feature Flags: Control access to features like verified badges, ad-free experience, and premium content
- Billing Cycles: Support for monthly, yearly, and custom billing periods
- Trial Periods: Configurable trial periods for new subscribers with automatic conversion
- Subscription Management: Users can upgrade, downgrade, and cancel subscriptions
- Grace Periods: Configurable grace periods for failed payments before suspension
Dynamic Payment Gateway Configuration: Admin-configurable payment providers without code changes
- Multiple Providers: Support for PayPal, Stripe, and extensible architecture for additional providers
- Real-time Provider Switching: Change payment providers instantly without application restarts
- Provider Priority: Configure fallback order for payment provider selection
- Environment Management: Separate sandbox/test and production configurations
- Secure Settings Storage: Encrypted storage of sensitive payment credentials in database
- Provider Health Monitoring: Real-time status monitoring and automatic failover
Comprehensive Payment Features:
- Subscription Webhooks: Automatic processing of payment provider webhooks for real-time updates
- Payment Retry Logic: Intelligent retry mechanisms for failed payments with exponential backoff
- Proration Support: Automatic proration for subscription upgrades and downgrades
- Payment Analytics: Detailed analytics and reporting for subscription metrics and revenue
- Admin Payment Dashboard: Complete payment management interface with transaction history
- Subscription Analytics: Revenue tracking, churn analysis, and subscription lifecycle metrics

Privacy & Security

Email Verification: Required email verification at signup to prevent bot registrations
- 6-digit verification codes sent via SendGrid with beautiful email templates
- Direct verification links for one-click email confirmation
- Login protection - unverified users cannot log in
- Dedicated verification pages with resend functionality for better UX
- Smart error handling - redirects to verification page when unverified users try to log in
Yap Privacy: Three levels - Public (everyone), Followers (followers only), Private (author only)
Privacy-Aware Timeline: Smart filtering based on user relationships and yap privacy
JWT Authentication: Secure token-based authentication
Password Reset: Email-based password recovery with 6-digit codes and email integration

User Experience

Responsive Design: Mobile-first approach with collapsible sidebar
Real-time Updates: Live timeline with instant social interaction feedback and immediate sidebar following list updates
Infinite Scroll: Smooth pagination with 25 posts per page for optimal performance
Return to Top: Convenient navigation button when reaching the end of timelines
Media Upload: Server-side storage for images and videos in yaps, messages, and profile pictures
Multi-Media Upload: Upload up to 10 photos and videos per post with drag-and-drop support and file validation
Photo Library: Comprehensive photo gallery showing all user images with slideshow navigation, keyboard controls, and theme-aware backgrounds
Video Processing: Automatic video processing with FFmpeg including format conversion, compression, and thumbnail generation
iPhone Photo Library Support: Unified media picker supporting both photos and videos from iPhone photo library via Safari
User Search: Find users by username or bio content
Hashtag Search: Search and discover hashtags with trending topics and post counts
Clean UI: 2015 Twitter-inspired design with modern touches
Individual Yap Pages: Dedicated URLs for each yap with shareable links
Share Modal: Popup sharing interface with social media integration (Twitter, Facebook, LinkedIn, Reddit)
Content Control: Delete buttons with confirmation dialogs for your own content
Optimized Images: Next.js Image component for better performance and loading
Real-time Messaging: Live message updates with automatic conversation refresh
Message Attachments: Send photos and videos in messages with preview and validation
Conversation Management: Infinite scroll message history with unread count indicators
Message Notifications: Red badge indicators showing unread message counts on tabs and conversation lists
Visual Read Status: Bold text and background highlights for conversations with unread messages
Dark Mode: Complete dark theme with toggle in Settings, synchronized across all platforms
Database Performance: Optimized with strategic indexing for fast timeline, profile, and messaging queries
Redis Caching: High-performance count caching for followers, posts, likes, comments, and notifications with automatic fallback

📸 Photo Library & Multi-Media Features

Multi-Media Posts: Upload up to 10 photos and videos per post with comprehensive media management
- Drag & Drop Upload: Intuitive drag-and-drop interface for easy media selection
- File Validation: Automatic format detection and size validation with user-friendly error messages
- Mixed Media Support: Combine photos and videos in a single post
- Upload Progress: Real-time upload progress indicators with cancel functionality
Photo Library: Dedicated photo gallery for browsing all user images
- Grid Layout: Clean 3-column grid displaying all photos from user's posts
- Slideshow Navigation: Full-screen photo viewing with left/right arrow navigation
- Keyboard Controls: Navigate photos using arrow keys (← → for navigation, Escape to close)
- Photo Counter: Shows current position (e.g., "3 of 15") with navigation hints
- Theme-Aware Backgrounds: Proper light/dark mode support for full-screen viewing
- Smooth Transitions: Enhanced hover effects and animations for better user experience
Media Gallery: Enhanced media viewing for posts with multiple images/videos
- Thumbnail Grid: Visual grid layout for posts with multiple media items
- Full-Screen Viewer: Click any image to view in full-screen with navigation controls
- Video Support: Integrated video playback with standard HTML5 controls
- Cross-Platform: Consistent media experience across web and mobile platforms

🎥 Video Features

Video Upload Support: Upload videos in posts and messages with comprehensive format support
- Supported Formats: MP4, MOV, AVI, WMV, FLV, WebM, MKV
- File Size Limits: Up to 100MB for videos, 5MB for images
- iPhone Compatibility: Native support for iPhone video formats (MOV, MP4)
Unified Media Picker: Single interface for selecting both photos and videos
- Web Frontend: iPhone Safari optimized file picker with photo library access
- Mobile App: Native photo library integration with expo-image-picker
- File Validation: Automatic format detection and size validation with user-friendly error messages
Video Processing Pipeline: Automatic server-side video processing with FFmpeg
- Format Conversion: Standardize videos to web-compatible formats
- Compression: Optimize file sizes while maintaining quality
- Thumbnail Generation: Automatic video thumbnail creation for previews
- Processing Status: Real-time status updates (Pending → Processing → Completed/Failed)
Video Display: Optimized video playback with controls and thumbnails
- Video Player: HTML5 video player with standard controls
- Thumbnail Previews: Show video thumbnails while processing
- Processing Indicators: Visual feedback during video processing
- Error Handling: Graceful handling of processing failures with retry options
Cross-Platform Consistency: Same video features across web and mobile platforms

🛠 Tech Stack

Backend (.NET 9 API)

.NET 9 - Minimal Web API
PostgreSQL - Database with Entity Framework Core and performance-optimized indexing
SignalR - Real-time WebSocket notifications for web clients
Firebase Admin SDK - Push notifications for mobile clients
Composite Notification System - Multi-provider notification system with automatic fallback
JWT Bearer - Authentication
BCrypt - Password hashing
SendGrid - Email service for verification and password reset (with AWS SES fallback)
File System Storage - Image and video upload and serving with multi-media support
Multi-Media Processing - Support for up to 10 photos/videos per post with PostMedia entity relationships
Groups & Communities - Complete group system with membership management and public group posts
Video Processing Service - FFmpeg-based video processing with RabbitMQ messaging
RabbitMQ - Message queue for asynchronous video processing tasks
Redis - High-performance caching for count operations and real-time data
AI Content Moderation - Python-based sentiment analysis and content moderation service
Payment Gateway System - Multi-provider payment processing with dynamic configuration
- PayPal Integration - Complete PayPal subscriptions API with webhook processing
- Stripe Integration - Full Stripe payment processing with advanced features
- Dynamic Configuration - Database-driven payment provider configuration with admin UI
- Subscription Management - Complete subscription lifecycle management with trials and grace periods
- Payment Analytics - Revenue tracking, subscription metrics, and payment analytics
- Webhook Processing - Secure webhook handling with signature verification and retry logic

Content Moderation Service (Python)

Python 3.11 - Modern Python runtime
Flask - Lightweight web framework for API endpoints
Gunicorn - Production WSGI server with worker processes
Pattern Matching - Advanced regex-based content analysis
Docker - Containerized deployment with health checks
RESTful API - HTTP-based communication with main API

Frontend (Next.js 15)

Next.js 15 - React framework with App Router
TypeScript - Type safety
Tailwind CSS - Utility-first styling
TanStack Query - Data fetching and caching
Axios - HTTP client
Lucide React - Beautiful icons
SignalR Client - Real-time WebSocket notifications
date-fns - Date formatting and manipulation
Multi-Media Components - PhotoGrid, MediaGallery, and FullScreenPhotoViewer for comprehensive media handling
Subscription System UI - SubscriptionTierBadge, payment configuration interface, and subscription management components
Admin Payment Interface - Complete payment provider configuration and subscription tier management UI

Mobile App (React Native + Expo)

React Native - Cross-platform mobile development
Expo - Development platform and tooling
TypeScript - Full type safety
React Navigation - Navigation library with stack navigation
TanStack Query - Data fetching (shared with web)
AsyncStorage - Local data persistence
Expo Image Picker - Camera and gallery integration for profile images, post images, and message attachments
Image Upload Support - Full image upload functionality for posts and messages with automatic HEIC to JPEG conversion
Profile Management - Complete profile editing with image upload functionality
Profile Images - Display and upload user profile pictures across all screens
Message Notifications - Real-time unread message badges and visual indicators
Enhanced Messaging UI - Image attachments, read status, and conversation management
Comments System - Full commenting functionality with dedicated screens, real-time updates, reply functionality, and optimized performance
Mentions & Notifications: @username mention system with comprehensive notification support and smart navigation
Hashtag Support: #hashtag tagging with search, trending topics, and clickable navigation
Content Reporting: Report objectionable posts and comments with system tag categorization and detailed reasons
Dark Mode: Complete dark theme support with toggle in Settings and persistent user preferences
Shared Package - 70-80% code reuse with web app

🏷️ Hashtag System

Yapplr features a comprehensive hashtag system that enables content discovery and trending topic tracking:

Core Features

Automatic Hashtag Detection: Posts automatically parse and extract #hashtag syntax
Clickable Hashtag Links: All hashtags are clickable throughout the application
Hashtag Search: Dedicated search functionality with post counts and trending indicators
Trending Algorithm: Real-time trending hashtag calculation based on recent activity
Privacy-Aware: Hashtag counts respect user privacy settings and blocking relationships

User Interface

Dedicated Trending Page: /trending with time period filters (Now, Today, This Week)
Hashtag Pages: Individual pages for each hashtag showing all related posts
Search Integration: Hashtag search tab in the main search interface
Trending Widget: Sidebar widget on homepage showing top trending hashtags
Post Creation Suggestions: Smart hashtag suggestions when creating posts

Technical Implementation

Database Optimization: Efficient many-to-many relationship with performance indexes
Real-time Updates: Live trending calculations with configurable refresh intervals
Cross-Platform: Consistent hashtag functionality across web and mobile apps
Analytics Ready: Built-in analytics service for hashtag metrics and usage tracking

API Endpoints

GET /api/tags/trending - Get trending hashtags
GET /api/tags/search/{query} - Search hashtags
GET /api/tags/tag/{tagName} - Get specific hashtag details
GET /api/tags/tag/{tagName}/posts - Get posts by hashtag
Analytics endpoints for detailed hashtag metrics

📸 Photo Library & Multi-Media API

Yapplr provides comprehensive API endpoints for multi-media post creation and photo library management.

Core Features

Multi-Media Posts: Support for up to 10 photos and videos per post
Photo Library: Dedicated endpoints for retrieving user's photo collections
Media Management: Complete CRUD operations for post media items
File Upload: Secure file upload with validation and processing

API Endpoints

Multi-Media Post Creation

POST /api/posts - Create post with multiple media items (up to 10 photos/videos)
POST /api/posts/upload-media - Upload media files with validation and processing
GET /api/posts/{id}/media - Get all media items for a specific post
DELETE /api/posts/{id}/media/{mediaId} - Remove specific media item from post

Photo Library

GET /api/posts/user/{userId}/photos - Get user's photo library with pagination
GET /api/posts/user/{userId}/photos?page={page}&limit={limit} - Paginated photo retrieval
Photo library automatically filters for image media types and respects privacy settings

Media Processing

GET /api/media/{id}/status - Check media processing status (Pending, Processing, Completed, Failed)
GET /api/media/{id}/thumbnail - Get video thumbnail or image preview
Media files are automatically processed and optimized for web delivery

Technical Implementation

PostMedia Entity: One-to-many relationship between Post and PostMedia for flexible media handling
Media Types: Support for Image and Video media types with extensible enum structure
File Validation: Automatic format detection, size limits (5MB images, 100MB videos)
Privacy Aware: All photo library queries respect post privacy settings and user relationships
Performance Optimized: Efficient database queries with proper indexing for fast photo retrieval

👥 Groups & Communities API

Yapplr provides comprehensive group functionality allowing users to create, join, and participate in public communities.

Core Features

Open Groups: All groups are public and open for anyone to join
Group Management: Create, update, and delete groups with proper ownership controls
Member Management: Join/leave groups with automatic membership tracking
Group Posts: Post content directly in groups with automatic public visibility
Search & Discovery: Full-text search across group names and descriptions
Member Roles: Support for Member, Moderator, and Admin roles (extensible for future features)

API Endpoints

Group Management

POST /api/groups - Create a new group (requires authentication)
GET /api/groups - Get all groups (paginated)
GET /api/groups/search?query={query} - Search groups by name or description
GET /api/groups/{id} - Get group details by ID
GET /api/groups/name/{name} - Get group details by name
PUT /api/groups/{id} - Update group (owner only)
DELETE /api/groups/{id} - Delete group (owner only)

Group Membership

POST /api/groups/{id}/join - Join a group
POST /api/groups/{id}/leave - Leave a group (owners cannot leave)
GET /api/groups/{id}/members - Get group members (paginated)
GET /api/groups/me - Get current user's groups
GET /api/groups/user/{userId} - Get groups for a specific user

Group Content

GET /api/groups/{id}/posts - Get posts in a group (paginated)
POST /api/posts - Create post (with optional groupId for group posts)

Technical Implementation

Database Schema: Groups, GroupMembers, and Posts tables with proper foreign key relationships
Unique Constraints: Group names must be unique across the platform
Cascade Deletes: Proper cleanup when groups or users are deleted
Performance Indexes: Optimized queries for group discovery, membership, and content retrieval
Public Content: All group posts are automatically public regardless of user privacy settings
Membership Validation: Users must be group members to post in groups
Role-Based Permissions: Group owners have full management rights

🤖 AI Content Moderation System

Yapplr features an advanced AI-powered content moderation system that automatically analyzes all posts and comments for policy violations, inappropriate content, and safety concerns.

Core Features

Real-time Analysis: Every post and comment is automatically analyzed upon creation
Pattern-Based Detection: Advanced regex patterns detect NSFW content, violence, harassment, hate speech, misinformation, and sensitive topics
Risk Assessment: Automated risk scoring (MINIMAL, LOW, MEDIUM, HIGH) with configurable thresholds
Smart Tag Suggestions: AI generates system tag recommendations with confidence scores
Content Classification: Automatic categorization into Content Warnings and Violations

Content Categories

Content Warnings

NSFW: Adult content, explicit material, mature themes
Violence: Violent content, weapons, gore, threats
Sensitive: Mental health topics, trauma, self-harm discussions
Spoiler: Plot spoilers, ending reveals, surprise content

Violations

Harassment: Bullying, intimidation, personal attacks
Hate Speech: Discriminatory language, slurs, prejudice
Misinformation: False information, conspiracy theories, hoaxes
Spam: Repetitive content, promotional spam, bot behavior

Technical Implementation

Microservice Architecture: Dedicated Python service for content analysis
Docker Deployment: Containerized sentiment analysis service with health checks
Scalable Design: Independent scaling of moderation service with resource limits
Fallback System: Graceful degradation when moderation service is unavailable
Performance Optimized: Efficient pattern matching with minimal latency impact

Configuration Options

{
  "ContentModeration": {
    "ServiceUrl": "http://content-moderation:8000",
    "Enabled": true,
    "AutoApplyTags": false,
    "RequireReviewThreshold": 0.5,
    "AutoHideThreshold": 0.8
  }
}

Admin Integration

Moderation Queue: Flagged content automatically appears in admin dashboard
AI Tag Review: Admins can approve or reject AI-suggested tags
Bulk Operations: Efficient review of multiple flagged items
Analytics: Track AI performance and moderation effectiveness
Manual Override: Admins can always override AI decisions

API Endpoints

POST /moderate - Analyze content for moderation (internal service)
GET /health - Content moderation service health check
Admin endpoints for reviewing AI-suggested tags and moderation decisions

🎯 User Trust Score System

Yapplr features an advanced user trust score system that provides intelligent, behavior-based moderation and content management. The system automatically calculates trust scores for all users based on their activity, behavior, and community standing.

Core Features

Dynamic Trust Calculation: Real-time trust scores (0.0-1.0) based on user behavior and activity patterns
Behavioral Analysis: Considers profile completeness, posting activity, community engagement, and moderation history
Trust-Based Moderation: Automatic content visibility adjustments and rate limiting based on user trust levels
Smart API Rate Limiting: Dynamic API rate limits from 0.25x (low trust) to 2x (high trust) normal limits across all endpoints
Auto-Hide Protection: Content from very low-trust users (< 0.1) automatically hidden from feeds
Moderation Priority: 1-5 priority levels for efficient moderation queue management

Trust Score Factors

Positive Factors (Increase Trust)

Profile Completeness: Bio, profile image, email verification (+0.1 to +0.3)
Positive Activity: Creating posts, engaging with content (+0.05 to +0.15 per action)
Community Standing: Receiving likes, follows, positive interactions (+0.02 to +0.1)
Account Age: Established accounts with consistent activity (+0.05 to +0.2)

Negative Factors (Decrease Trust)

Moderation Actions: Content hidden, user suspended, policy violations (-0.1 to -0.5)
Reported Content: Posts/comments reported by other users (-0.05 to -0.2)
Spam Behavior: Excessive posting, repetitive content (-0.1 to -0.3)
Inactivity Decay: Gradual score reduction for inactive accounts (-0.01 per week)

Trust-Based Features

Content Visibility Levels

Hidden (< 0.1): Content hidden from all feeds and searches
Limited (0.1-0.3): Reduced visibility, requires user action to view
Reduced (0.3-0.5): Lower priority in feeds, limited reach
Normal (0.5-0.8): Standard visibility and engagement
Full (0.8+): Maximum visibility and engagement opportunities

Action Thresholds

Create Posts: 0.1 minimum trust score
Create Comments: 0.1 minimum trust score
Like Content: 0.05 minimum trust score
Report Content: 0.2 minimum trust score
Send Messages: 0.3 minimum trust score

Rate Limiting Multipliers

Very Low Trust (< 0.2): 0.25x normal rate limits
Low Trust (0.2-0.4): 0.5x normal rate limits
Medium Trust (0.4-0.6): 1.0x normal rate limits
High Trust (0.6-0.8): 1.5x normal rate limits
Very High Trust (0.8+): 2.0x normal rate limits

Technical Implementation

Background Service: Automated trust score recalculation and maintenance
Real-time Updates: Trust scores update immediately based on user actions
Audit Trail: Complete history of trust score changes with detailed metadata
Safe Defaults: System defaults to allowing actions if trust score calculation fails
Performance Optimized: Efficient database queries with proper indexing
Admin Override: Administrators can manually adjust trust scores with reason tracking

Admin Features

Trust Score Dashboard: View platform-wide trust score statistics and distribution
User Trust Management: View individual user trust scores and adjustment history
Manual Adjustments: Manually increase or decrease user trust scores with reason tracking
Trust Score Analytics: Detailed breakdown of factors affecting user trust scores
Moderation Integration: Trust scores automatically factor into moderation decisions

Configuration Options

{
  "TrustScore": {
    "EnableBackgroundService": true,
    "RecalculationIntervalMinutes": 60,
    "InactivityDecayDays": 7,
    "DefaultNewUserScore": 1.0,
    "MinimumActionThresholds": {
      "CreatePost": 0.1,
      "CreateComment": 0.1,
      "LikeContent": 0.05,
      "ReportContent": 0.2,
      "SendMessage": 0.3
    }
  }
}

API Endpoints

GET /api/admin/trust-scores/ - Get all user trust scores with filtering
GET /api/admin/trust-scores/{userId} - Get specific user trust score
GET /api/admin/trust-scores/{userId}/history - Get trust score change history
GET /api/admin/trust-scores/{userId}/factors - Get trust score factor breakdown
PUT /api/admin/trust-scores/{userId} - Manually adjust user trust score
GET /api/admin/trust-scores/statistics - Get platform trust score statistics

💳 Payment Gateway Configuration & Subscription System

Yapplr features a comprehensive payment system with dynamic gateway configuration and flexible subscription management.

Core Features

Dynamic Payment Provider Configuration: Configure payment providers through admin interface without code changes
Multi-Provider Support: PayPal, Stripe, and extensible architecture for additional providers
Real-time Configuration Updates: Change payment settings instantly without application restarts
Secure Credential Storage: Encrypted storage of sensitive payment provider credentials
Subscription Lifecycle Management: Complete subscription creation, management, and cancellation workflows
Trial Period Support: Configurable trial periods with automatic conversion to paid subscriptions
Payment Analytics: Comprehensive analytics and reporting for subscription metrics and revenue tracking

Subscription Tiers

Flexible Tier Management: Create unlimited subscription tiers with custom pricing and features
Feature Flags: Control access to premium features like verified badges and ad-free experience
Billing Cycles: Support for monthly, yearly, and custom billing periods
Tier Comparison: Visual tier comparison interface for users to choose the best plan
Automatic Tier Assignment: Seamless tier assignment upon successful payment

Payment Provider Configuration

Admin Interface Features

Provider Management: Enable/disable payment providers with priority ordering
Environment Configuration: Separate sandbox/test and production environment settings
Credential Management: Secure storage and management of API keys, secrets, and webhooks
Health Monitoring: Real-time provider status monitoring with automatic failover
Test Connectivity: Built-in provider connectivity testing and validation

Supported Providers

PayPal: Complete PayPal subscriptions API integration with webhook processing
Stripe: Full Stripe payment processing with advanced subscription features
Extensible Architecture: Easy integration of additional payment providers

API Endpoints

Subscription Management

GET /api/subscriptions/tiers - Get all active subscription tiers
GET /api/subscriptions/tiers/{id} - Get specific subscription tier details
GET /api/subscriptions/my-subscription - Get current user's subscription
POST /api/subscriptions/assign-tier - Assign subscription tier to user
DELETE /api/subscriptions/remove-subscription - Remove user's subscription

Payment Processing

GET /api/payments/providers - Get available payment providers
POST /api/payments/subscriptions - Create new subscription with payment
GET /api/payments/subscriptions/current - Get current user's subscription details
POST /api/payments/subscriptions/cancel - Cancel current subscription
POST /api/payments/webhooks/{provider} - Process payment provider webhooks

Admin Configuration

GET /api/admin/payment-configuration/summary - Get payment configuration overview
GET /api/admin/payment-configuration/providers - Get all payment provider configurations
POST /api/admin/payment-configuration/providers - Create new payment provider configuration
PUT /api/admin/payment-configuration/providers/{id} - Update payment provider configuration
DELETE /api/admin/payment-configuration/providers/{id} - Delete payment provider configuration
POST /api/admin/payment-configuration/providers/{id}/test - Test payment provider connectivity
GET /api/admin/payment-configuration/global - Get global payment configuration
PUT /api/admin/payment-configuration/global - Update global payment configuration

Admin Subscription Management

GET /api/admin/subscriptions/tiers - Get all subscription tiers (including inactive)
POST /api/admin/subscriptions/tiers - Create new subscription tier
PUT /api/admin/subscriptions/tiers/{id} - Update subscription tier
DELETE /api/admin/subscriptions/tiers/{id} - Delete subscription tier
GET /api/admin/subscriptions/users - Get user subscriptions with filtering
GET /api/admin/subscriptions/analytics - Get subscription analytics and metrics

Technical Implementation

Database-Driven Configuration: All payment settings stored in database with encryption for sensitive data
Provider Abstraction: Clean abstraction layer allowing easy addition of new payment providers
Webhook Security: Automatic signature verification and replay attack prevention
Retry Logic: Intelligent retry mechanisms for failed payments with exponential backoff
Audit Trail: Complete audit logging for all payment configuration changes and transactions
Performance Optimized: Efficient database queries with proper indexing for payment operations

Configuration Options

{
  "PaymentSystem": {
    "EnableSubscriptions": true,
    "DefaultTrialDays": 14,
    "GracePeriodDays": 7,
    "MaxRetryAttempts": 3,
    "RetryIntervalDays": 3,
    "EnableProration": true,
    "WebhookTimeoutSeconds": 10,
    "VerifyWebhookSignatures": true
  }
}

🚦 Smart API Rate Limiting

Yapplr implements intelligent API rate limiting that dynamically adjusts based on user trust scores, providing a fair and secure experience for all users while preventing abuse.

Core Features

Trust-Based Rate Limiting: Dynamic rate limits that scale with user trust scores (0.25x to 2x normal limits)
Operation-Specific Limits: Different rate limits for different types of API operations
Burst Protection: Short-term burst detection to prevent rapid-fire requests
Automatic Blocking: Users with excessive violations are temporarily blocked
Comprehensive Monitoring: Real-time statistics and violation tracking

Rate Limit Configuration

Base Rate Limits (per operation type)

Create Post: 5/minute, 50/hour, 500/day (burst: 3)
Create Comment: 10/minute, 100/hour, 1000/day (burst: 5)
Like/Unlike Post: 30/minute, 300/hour, 3000/day (burst: 15)
Follow/Unfollow User: 5-10/minute, 50-100/hour, 500-1000/day (burst: 3-5)
Report Content: 2/minute, 20/hour, 100/day (burst: 1)
Send Message: 10/minute, 100/hour, 1000/day (burst: 5)
Upload Media: 3/minute, 30/hour, 200/day (burst: 2)
Search: 20/minute, 200/hour, 2000/day (burst: 10)
General Operations: 60/minute, 600/hour, 6000/day (burst: 30)

Trust Score Multipliers

Very Low Trust (< 0.2): 0.25x rate limits (quarter normal limits)
Low Trust (0.2-0.4): 0.5x rate limits (half normal limits)
Medium Trust (0.4-0.6): 1.0x rate limits (normal limits)
High Trust (0.6-0.8): 1.5x rate limits (50% more requests)
Very High Trust (0.8+): 2.0x rate limits (double normal limits)

Violation Handling

Burst Violations: 10-second cooldown period
Rate Limit Violations: Retry-after headers with appropriate wait times
Auto-Blocking: Users with 15+ violations in 24 hours are blocked for 2 hours
Progressive Penalties: Repeated violations result in longer blocking periods

Exempt Endpoints

The following endpoints are exempt from rate limiting:

Authentication endpoints (/api/auth/*)
Health checks (/api/health)
User profile retrieval (/api/users/me)
Rate limit status endpoints (/api/security/rate-limits/*)

Response Headers

Rate-limited responses include helpful headers:

X-RateLimit-Remaining: Number of requests remaining in current window
X-RateLimit-Reset: Unix timestamp when rate limit resets
X-RateLimit-Type: Indicates "trust-based" rate limiting
Retry-After: Seconds to wait before retrying (when rate limited)

Configuration Options

System-Wide Configuration

Rate limiting can be configured globally via appsettings.json:

{
  "RateLimiting": {
    "Enabled": true,
    "TrustBasedEnabled": true,
    "BurstProtectionEnabled": true,
    "AutoBlockingEnabled": true,
    "AutoBlockViolationThreshold": 15,
    "AutoBlockDurationHours": 2,
    "ApplyToAdmins": false,
    "ApplyToModerators": false,
    "FallbackMultiplier": 1.0
  }
}

Configuration Options:

Enabled: Global enable/disable flag for all rate limiting
TrustBasedEnabled: Enable/disable trust score multipliers
BurstProtectionEnabled: Enable/disable burst protection
AutoBlockingEnabled: Enable/disable automatic user blocking
AutoBlockViolationThreshold: Number of violations before auto-blocking (default: 15)
AutoBlockDurationHours: Duration in hours for auto-blocking (default: 2)
ApplyToAdmins: Whether to apply rate limits to admin users (default: false)
ApplyToModerators: Whether to apply rate limits to moderators (default: false)
FallbackMultiplier: Rate limit multiplier when trust-based is disabled (default: 1.0)

Per-User Configuration

Individual users can have rate limiting overrides:

Rate Limiting Enabled: Override global setting for specific user
Trust-Based Enabled: Override trust-based rate limiting for specific user
Manual Blocking: Admins can manually block/unblock users from API access

Admin Controls

Administrators can manage rate limiting through the admin interface:

View and modify system-wide rate limiting configuration
View per-user rate limiting settings and violations
Enable/disable rate limiting for individual users
Manually block/unblock users from API access
Reset user rate limits and violation history
View comprehensive rate limiting statistics

Technical Implementation

Middleware-Based: Transparent rate limiting applied at the middleware level
Trust Integration: Seamlessly integrates with the existing trust score system
Memory-Efficient: In-memory tracking with automatic cleanup of old data
Production-Ready: Designed for Redis or distributed cache in production environments
Highly Configurable: System-wide and per-user configuration options

API Endpoints

User Endpoints

GET /api/security/rate-limits/violations - Get current user's rate limit violations
GET /api/security/rate-limits/stats - Get platform-wide rate limiting statistics

Admin Configuration Endpoints

GET /api/security/admin/rate-limits/config - Get current rate limiting configuration
PUT /api/security/admin/rate-limits/config - Update rate limiting configuration
GET /api/security/admin/rate-limits/stats - Get comprehensive rate limiting statistics

Admin User Management Endpoints

GET /api/security/admin/rate-limits/users/{userId} - Get user's rate limiting settings
PUT /api/security/admin/rate-limits/users/{userId} - Update user's rate limiting settings
DELETE /api/security/admin/rate-limits/users/{userId}/reset - Reset user's rate limits and violations
POST /api/security/admin/rate-limits/users/{userId}/block - Block user from API access
DELETE /api/security/admin/rate-limits/users/{userId}/block - Unblock user from API access

💳 Payment Gateway Configuration & Subscription System

Yapplr features a comprehensive payment system with dynamic gateway configuration and flexible subscription management.

Core Features

Dynamic Payment Provider Configuration: Configure payment providers through admin interface without code changes
Multi-Provider Support: PayPal, Stripe, and extensible architecture for additional providers
Real-time Configuration Updates: Change payment settings instantly without application restarts
Secure Credential Storage: Encrypted storage of sensitive payment provider credentials
Subscription Lifecycle Management: Complete subscription creation, management, and cancellation workflows
Trial Period Support: Configurable trial periods with automatic conversion to paid subscriptions
Payment Analytics: Comprehensive analytics and reporting for subscription metrics and revenue tracking

Subscription Tiers

Flexible Tier Management: Create unlimited subscription tiers with custom pricing and features
Feature Flags: Control access to premium features like verified badges and ad-free experience
Billing Cycles: Support for monthly, yearly, and custom billing periods
Tier Comparison: Visual tier comparison interface for users to choose the best plan
Automatic Tier Assignment: Seamless tier assignment upon successful payment

Payment Provider Configuration

Admin Interface Features

Provider Management: Enable/disable payment providers with priority ordering
Environment Configuration: Separate sandbox/test and production environment settings
Credential Management: Secure storage and management of API keys, secrets, and webhooks
Health Monitoring: Real-time provider status monitoring with automatic failover
Test Connectivity: Built-in provider connectivity testing and validation

Supported Providers

PayPal: Complete PayPal subscriptions API integration with webhook processing
Stripe: Full Stripe payment processing with advanced subscription features
Extensible Architecture: Easy integration of additional payment providers

API Endpoints

Subscription Management

GET /api/subscriptions/tiers - Get all active subscription tiers
GET /api/subscriptions/tiers/{id} - Get specific subscription tier details
GET /api/subscriptions/my-subscription - Get current user's subscription
POST /api/subscriptions/assign-tier - Assign subscription tier to user
DELETE /api/subscriptions/remove-subscription - Remove user's subscription

Payment Processing

GET /api/payments/providers - Get available payment providers
POST /api/payments/subscriptions - Create new subscription with payment
GET /api/payments/subscriptions/current - Get current user's subscription details
POST /api/payments/subscriptions/cancel - Cancel current subscription
POST /api/payments/webhooks/{provider} - Process payment provider webhooks

Admin Configuration

GET /api/admin/payment-configuration/summary - Get payment configuration overview
GET /api/admin/payment-configuration/providers - Get all payment provider configurations
POST /api/admin/payment-configuration/providers - Create new payment provider configuration
PUT /api/admin/payment-configuration/providers/{id} - Update payment provider configuration
DELETE /api/admin/payment-configuration/providers/{id} - Delete payment provider configuration
POST /api/admin/payment-configuration/providers/{id}/test - Test payment provider connectivity
GET /api/admin/payment-configuration/global - Get global payment configuration
PUT /api/admin/payment-configuration/global - Update global payment configuration

Admin Subscription Management

GET /api/admin/subscriptions/tiers - Get all subscription tiers (including inactive)
POST /api/admin/subscriptions/tiers - Create new subscription tier
PUT /api/admin/subscriptions/tiers/{id} - Update subscription tier
DELETE /api/admin/subscriptions/tiers/{id} - Delete subscription tier
GET /api/admin/subscriptions/users - Get user subscriptions with filtering
GET /api/admin/subscriptions/analytics - Get subscription analytics and metrics

Technical Implementation

Database-Driven Configuration: All payment settings stored in database with encryption for sensitive data
Provider Abstraction: Clean abstraction layer allowing easy addition of new payment providers
Webhook Security: Automatic signature verification and replay attack prevention
Retry Logic: Intelligent retry mechanisms for failed payments with exponential backoff
Audit Trail: Complete audit logging for all payment configuration changes and transactions
Performance Optimized: Efficient database queries with proper indexing for payment operations

👤 Admin User Management API

Comprehensive user management endpoints for admin interface:

User Details Endpoints

GET /api/admin/users/{id} - Get comprehensive user details including profile, trust score, rate limiting settings, activity statistics, and moderation history
PUT /api/admin/users/{id}/rate-limiting - Update user-specific rate limiting settings with audit trail
POST /api/admin/users/{id}/change-role - Change user role with reason tracking and audit logging

🏃‍♂️ Quick Start

Prerequisites

.NET 9 SDK
Node.js 18+
PostgreSQL 12+
Redis 7+ (or Docker for Redis container)
Docker (for content moderation service and Redis)

1. Backend Setup

# Navigate to API directory
cd Yapplr.Api

# Install dependencies
dotnet restore

# Setup database (creates yapplr_db)
./setup-db.sh

# Start the API (migrations run automatically at startup)
dotnet run

The API will be available at http://localhost:5161

Note: Database migrations now run automatically when the API starts, ensuring your database is always up-to-date.

2. Frontend Setup

# Navigate to frontend directory
cd yapplr-frontend

# Install dependencies
npm install

# Create environment file
echo "NEXT_PUBLIC_API_URL=http://localhost:5161" > .env.local

# Start the frontend
npm run dev

The frontend will be available at http://localhost:3000

3. Content Moderation Service Setup

# Navigate to sentiment analysis directory
cd sentiment-analysis

# Build and run the Docker container
docker build -t sentiment-analysis .
docker run -d -p 8000:8000 --name sentiment-analysis-container sentiment-analysis

# Verify the service is running
curl http://localhost:8000/health

The content moderation service will be available at http://localhost:8000

Note: The API automatically connects to the content moderation service. If the service is unavailable, content moderation will be disabled gracefully without affecting other functionality.

4. Redis Setup (Recommended for Performance)

Redis provides high-performance caching for count operations, dramatically improving response times.

Option A: Docker Redis (Recommended)

# Using Docker Compose (includes Redis)
docker compose -f docker-compose.local.yml up --build -d

# Verify Redis is running
docker compose -f docker-compose.local.yml exec redis redis-cli ping
# Should return: PONG

Option B: Local Redis Installation

# macOS
brew install redis
brew services start redis

# Ubuntu/Debian
sudo apt update && sudo apt install redis-server
sudo systemctl start redis-server

# Windows
# Download from https://redis.io/download

Configuration

Add to Yapplr.Api/appsettings.Development.json:

{
  "Redis": {
    "ConnectionString": "localhost:6379"
  }
}

Verify Redis Caching

# Check if caching is working
curl http://localhost:5161/health

# Monitor Redis keys (should see count:* keys)
redis-cli keys "count:*"

Note: If Redis is unavailable, the application automatically falls back to memory caching without affecting functionality.

5. Mobile App Setup (Optional)

# Navigate to mobile app directory
cd YapplrMobile

# Install dependencies
npm install --legacy-peer-deps

# Build shared package
cd ../yapplr-shared
npm install && npm run build

# Start mobile development server
cd ../YapplrMobile
npx expo start

Use Expo Go app on your phone to scan the QR code, or press i for iOS simulator / a for Android emulator.

Mobile App Features

Complete Profile Management: Edit bio, pronouns, tagline, birthday, and profile images
Profile Image Upload: Camera icon overlay for easy profile picture changes with gallery picker
Profile Information Display: View all profile information including pronouns next to username
Profile Images Everywhere: User avatars displayed in timeline posts, user lists, and profiles
Following/Followers Lists: Tap Following or Followers count to view detailed lists and navigate to user profiles with images
Enhanced Profile Layout: Consolidated profile design with image on left, name/pronouns aligned to top, and tagline positioned directly underneath
Enhanced Messaging: Send text and photo messages with real-time delivery and read status
Message Notifications: Red badge on Messages tab showing total unread message count
Visual Conversation Indicators: Bold text and background highlights for conversations with unread messages
Image Message Support: Send photos in messages with gallery picker and preview functionality
Post Image Upload: Create posts with images using gallery picker with automatic compression for large iPhone photos
HEIC Format Support: Automatic conversion of iPhone HEIC images to JPEG format for compatibility
Image Compression: Smart compression to handle large iPhone photos within 5MB API limits while maintaining quality
Automatic Read Marking: Conversations automatically marked as read when opened
Comments System: Dedicated comment screens with post context, real-time comment count updates, and auto-scroll to new comments
Optimized Performance: Memoized components prevent image flashing and unnecessary re-renders during typing
Navigation: Stack-based navigation with proper screen transitions
API Integration: Full integration with backend API for profile updates and image uploads
Image Fallbacks: Graceful fallback to user initials when no profile image is available
Password Recovery: Complete password reset flow with 6-digit email codes and automatic navigation
Content Reporting: Report inappropriate posts and comments with system tag categorization (Violation, Safety, Content Warning, Quality/Spam) and detailed reason submission
Dark Mode: Complete dark theme with toggle in Settings, synchronized with web app preferences

6. Firebase Setup (Required for Real-time Notifications)

Firebase provides real-time push notifications for all social interactions. The system supports both development and production environments with automatic fallback.

Development Setup (Application Default Credentials)

# Install Google Cloud CLI
# macOS: brew install google-cloud-sdk
# Windows: Download from https://cloud.google.com/sdk/docs/install

# Authenticate with your Google account
gcloud auth application-default login

Production Setup (Service Account Key)

Create Firebase Project: Go to Firebase Console and create a new project
Generate Service Account Key:
- Go to Project Settings → Service Accounts
- Click "Generate new private key"
- Download the JSON file

Configure Environment Variables:

# For production deployment, set these environment variables:
Firebase__ProjectId=your-firebase-project-id
Firebase__ServiceAccountKey={"type":"service_account","project_id":"your-project-id",...}

Frontend Configuration

The frontend now uses SignalR-only for notifications. Add to yapplr-frontend/.env.local:

NEXT_PUBLIC_API_URL=http://localhost:5161
NEXT_PUBLIC_ENABLE_SIGNALR=true

7. Payment System Setup (Optional - For Subscription Features)

The payment system enables subscription tiers and monetization features. This is optional for basic social media functionality.

Payment Provider Setup

PayPal Setup (Optional):
- Create a PayPal Developer Account
- Create an application and get Client ID and Secret
- Set up products and billing plans for subscriptions
- Configure webhook endpoints for real-time updates
Stripe Setup (Optional):
- Create a Stripe Account
- Get API keys (Publishable and Secret keys)
- Set up products and prices for subscription tiers
- Configure webhook endpoints for payment events

Admin Configuration

Access Payment Configuration:
- Log in as an admin user
- Navigate to /admin/payment-configuration
- Configure payment providers with your credentials
Create Subscription Tiers:
- Navigate to /admin/subscriptions
- Create subscription tiers with pricing and features
- Set up trial periods and billing cycles

Configuration Example

Add to Yapplr.Api/appsettings.Development.json:

{
  "PaymentSystem": {
    "EnableSubscriptions": true,
    "DefaultTrialDays": 14,
    "GracePeriodDays": 7
  }
}

Note: Payment providers can be configured entirely through the admin interface. No code changes required for adding or modifying payment settings.

For detailed payment gateway setup instructions, see PAYMENT_GATEWAY_CONFIGURATION.md.

8. SendGrid Setup (Required for Email Verification & Password Reset)

SendGrid provides reliable email delivery for email verification and password reset functionality.

Development Setup

Create SendGrid Account: Go to SendGrid and sign up for a free account
Get API Key:
- Go to Settings → API Keys
- Click "Create API Key"
- Choose "Restricted Access" and give it a name
- Under "Mail Send", select "Full Access"
- Copy the API key (you won't see it again!)
Verify Sender Identity:
- Go to Settings → Sender Authentication
- Click "Verify a Single Sender"
- Fill out the form with your details
- Verify your email address

Configuration

Add to Yapplr.Api/appsettings.Development.json:

{
  "SendGridSettings": {
    "ApiKey": "SG.your-api-key-here",
    "FromEmail": "your-verified-email@domain.com",
    "FromName": "Your App Name"
  },
  "EmailProvider": "SendGrid"
}

Production Deployment

For production, use GitHub secrets:

PROD_SENDGRID_API_KEY: Your SendGrid API key
PROD_SENDGRID_FROM_EMAIL: Your verified sender email
PROD_SENDGRID_FROM_NAME: Your app name
PROD_EMAIL_PROVIDER: SendGrid

Features

Dual Authentication: Automatic fallback from Service Account Key to Application Default Credentials
Production Ready: Service Account Key authentication for reliable deployment
Real-time Messaging: Instant notifications for comments, mentions, likes, reposts, and follows
Smart Notifications: Prevents duplicate notifications (e.g., no double notifications when post owner is mentioned in comments)
Cross-Platform: Works on web browsers with push notification support
Background Notifications: Notifications work even when the app is closed

8. Admin Setup (Creating Admin Users)

The platform includes comprehensive admin and moderation tools. To access the admin interface, you need to create admin users using command-line tools.

Creating the First Admin User

# Navigate to API directory
cd Yapplr.Api

# Create an admin user (requires API to be running)
dotnet run create-admin <username> <email> <password>

# Example:
dotnet run create-admin admin admin@yapplr.com SecurePassword123!

Promoting Existing Users

# Promote an existing user to Admin or Moderator
dotnet run promote-user <username-or-email> <role>

# Examples:
dotnet run promote-user john@example.com Admin
dotnet run promote-user moderator1 Moderator

Admin Interface Access

Once you have admin users created:

Login: Use your admin credentials to log into the web app
Access Admin Panel: Navigate to /admin or use the admin navigation
Admin Dashboard: View platform statistics, user metrics, and moderation queue
Available Admin Pages:
- Dashboard (/admin) - Overview and quick actions
- Users (/admin/users) - User management and moderation
- User Details (/admin/users/{id}) - Comprehensive user information and management
- Posts (/admin/posts) - Post moderation and management
- Comments (/admin/comments) - Comment moderation
- Content Queue (/admin/queue) - Flagged content review
- System Tags (/admin/system-tags) - Content labeling system
- Appeals (/admin/appeals) - User appeal management
- Audit Logs (/admin/audit-logs) - Action tracking and accountability
- Analytics (/admin/analytics) - Platform insights and reporting

Admin Features

Role-Based Access: Different permissions for Admin vs Moderator roles
Comprehensive User Management: Detailed user profiles with trust score analysis, rate limiting controls, and complete moderation history
User Details Pages: Click any username to access comprehensive user information and management tools
Rate Limiting Controls: Override rate limiting settings for individual users with audit trail
Content Moderation: Hide, delete, and tag posts and comments
Bulk Actions: Efficiently moderate multiple items simultaneously
Audit Logging: Complete tracking of all administrative actions
Real-time Stats: Live dashboard with platform metrics and activity

📱 Key Features in Detail

Timeline & Reyaps

Mixed Timeline: Shows both original yaps and reyaps chronologically
Infinite Scroll: Automatic loading of 25 posts per page with smooth pagination
Return to Top: Quick navigation button when reaching the end of content
Reyap Attribution: Clear "User reyapped" headers with original content
Privacy Respect: Only shows reyaps of content you're allowed to see
User Profiles: Both original yaps and reyaps appear on user profiles

Yap Privacy System

Public Yaps: Visible to everyone, can be reyapped by anyone
Followers Yaps: Only visible to followers and author
Private Yaps: Only visible to the author
Smart Filtering: Timeline automatically filters based on relationships

Hashtag System

#Hashtag Tagging: Tag posts with hashtags using #hashtag syntax with automatic detection and validation
Clickable Hashtags: All #hashtag tags are automatically converted to clickable links leading to hashtag pages
Hashtag Search: Search for hashtags with autocomplete and real-time results showing post counts
Trending Hashtags: Algorithm-based trending hashtag detection based on recent activity and usage patterns
Hashtag Pages: Dedicated pages for each hashtag showing all posts containing that tag with infinite scroll
Tag Analytics: Comprehensive hashtag metrics including total posts, recent activity, and usage statistics
Cross-Platform Support: Consistent hashtag experience across web and mobile platforms
Privacy Aware: Hashtag searches respect post privacy settings and user blocking relationships
Performance Optimized: Database indexes and efficient queries for fast hashtag operations
Tag Validation: Robust hashtag validation (1-50 characters, starts with letter, alphanumeric + underscore/hyphen)
Case Insensitive: All hashtags normalized to lowercase for consistent behavior
Real-time Updates: Hashtag post counts update automatically when posts are created or deleted
Search Integration: Hashtag search integrated into main search page with tabbed interface
Mobile Optimized: Touch-friendly hashtag interaction with proper navigation in mobile apps

Link Preview System

Automatic URL Detection: Posts automatically detect and parse HTTP/HTTPS URLs with comprehensive regex patterns
Visual Link Previews: Rich preview cards showing title, description, images, and site information from Open Graph metadata
Error Handling: Clear warning messages for inaccessible links (404, 401, 403, timeouts, network errors)
Status Tracking: Comprehensive status system (Pending, Success, NotFound, Unauthorized, Forbidden, Timeout, etc.)
Performance Optimization: Link previews are cached to avoid duplicate fetching of the same URLs
Security Features: URL validation, content type checking, size limits, and timeout protection
Cross-Platform Support: Consistent link preview experience across web and mobile applications
External Image Support: Properly configured Next.js image optimization for external preview images
Smart Parsing: Extracts metadata using Open Graph tags with fallback to Twitter Card and standard HTML meta tags
Loading States: Shows "Loading preview..." indicators while fetching link metadata
Clickable Previews: Preview cards are clickable and open links in new tabs with proper security attributes
Mobile Touch Support: Touch-friendly preview cards with proper React Native styling and Linking integration
Database Optimization: Efficient link preview storage with proper indexing and relationship management
API Integration: RESTful endpoints for link preview management and processing

Mentions & Notifications System

@Username Mentions: Mention users in posts and comments using @username syntax with automatic detection
Clickable Mentions: All @username mentions are automatically converted to clickable profile links
Real-time Notifications: Instant Firebase push notifications for mentions, likes, reposts, follows, and comments
Follow Notifications: Get notified immediately when someone follows you with navigation to their profile
Like Notifications: Real-time alerts when someone likes your posts with direct navigation to the liked post
Repost Notifications: Instant notifications when someone reposts your content with navigation to the original post
Mention Notifications: Immediate alerts when mentioned in posts or comments with smart navigation to context
Comment Notifications: Real-time notifications when someone comments on your posts
Smart Navigation: Click notifications to navigate directly to relevant content (posts, comments, profiles)
Comment Scrolling: Automatic scrolling and highlighting when navigating to specific comments from notifications
Notification Badges: Red badge indicators showing unread notification count in sidebar
Privacy Respect: Blocked users don't receive notifications from users who blocked them
Notification Management: Mark individual notifications or all notifications as read
Notification History: Paginated notification list with timestamps and context
Background Push: Notifications work even when app is closed or minimized
Cross-Platform: Consistent notification experience across web and mobile platforms

Comments System

Dedicated Comment Screens: Full-screen comment interface showing post context and all comments
Real-time Updates: Comment counts update immediately across all screens when comments are added
Auto-scroll: Automatically scroll to show newly added comments for better user experience
Reply Functionality: Reply to specific comments with automatic @username prefilling and reply context UI
Smart Reply Protection: Prevents accidental removal of @username when replying to comments
Reply Cancellation: Cancel reply mode to return to normal commenting with clear UI indicators
Post Context: Display original post content at the top of comment screens for context
User Information: Show commenter avatars, usernames, and timestamps for each comment
Performance Optimized: Memoized components prevent image flashing and unnecessary re-renders
Cross-Platform: Consistent commenting experience across web and mobile platforms
Edit Indicators: Visual indicators for edited comments with "(edited)" labels
Mobile Optimized: Touch-friendly interface with proper keyboard handling and scroll behavior

Follow System

Real-time Counts: Instant follower/following count updates
Immediate Sidebar Updates: Following list in sidebar updates instantly when following/unfollowing users
Tabbed Profile Interface: Clean tabbed navigation on profile pages with Posts, Following (count), and Followers (count) tabs
Following/Followers Lists: Detailed user lists accessible through profile tabs showing profile images, usernames, pronouns, and bio snippets
Profile Navigation: Click any user in Following/Followers lists to navigate to their profile
User-Specific Lists: View following/followers for any user profile, not just your own
Consistent Username Display: Clean @username format throughout the application eliminating redundant username displays
Privacy Integration: Following relationships affect content visibility
Profile Integration: Follow/unfollow buttons on user profiles
Timeline Impact: Following users affects your timeline content
Online Status: Green circle indicators showing when followed users are currently online (active within 5 minutes)
Mobile Support: Full Following/Followers list functionality available in mobile app with enhanced profile layout

Follow Request Approval System

Optional Follow Approval: Users can require approval for follow requests in their preferences
Request Workflow: Send follow requests that show "Request Pending" until processed
Accept/Decline Actions: Notification-based approval system with Accept/Decline buttons
Persistent Status Tracking: Complete history of all follow requests with status (pending/approved/denied)
Smart Button States: Profile buttons dynamically show "Follow", "Request to Follow", "Request Pending", or "Following"
Re-request Capability: Users can send new follow requests after being denied
Notification Integration: Follow requests appear in notifications with actionable buttons
Status Persistence: Follow request status survives page refreshes and app restarts
Audit Trail: Complete history of follow request interactions for transparency
Automatic Unfollowing: Blocking users automatically removes follow relationships

User Management & Privacy

User Blocking: Block users to prevent interactions and hide content
Automatic Unfollowing: Blocking automatically removes follow relationships
Settings Page: Dedicated settings interface with organized sections
Blocklist Management: View and unblock previously blocked users
Privacy Controls: Comprehensive privacy system with relationship-based filtering
Profile Editing: Complete profile management with bio, pronouns, tagline, and birthday
Profile Display: Enhanced profile information display with pronouns shown inline with username
Dark Mode: System-wide dark theme with user preferences stored in database and synchronized across platforms

Image Management

Yap Images: Upload images with yaps (server-side storage) with support for JPG, PNG, GIF, WebP formats
Profile Images: Upload and manage profile pictures across web and mobile platforms
Message Images: Send photo attachments in private messages with gallery picker integration
Mobile Image Support: Full image upload functionality in React Native with automatic HEIC to JPEG conversion
Smart Compression: Automatic image compression for large iPhone photos to meet 5MB API limits
Format Validation: Server-side validation of image formats, file sizes, and security signatures
Image Serving: Optimized image serving with proper content types and secure file access
File Management: Secure image upload with comprehensive validation and error handling

Private Messaging System

Direct Messages: Send private messages between users with text and photo attachments
Conversation Threads: Organized message conversations with participant management
Real-time Updates: Live message updates with automatic refresh (5-second intervals)
Read Status Tracking: Mark conversations as read with timestamp tracking and automatic read marking
Infinite Scroll: Load message history with pagination (25 messages per page)
Blocking Integration: Blocked users cannot send messages to each other
Message Composer: Rich message input with photo upload and character limits
Unread Indicators: Visual unread message counts on conversation list with bold text and background highlights
Notification Badges: Red badge on Messages tab/link showing total count of conversations with unread messages
Mobile Image Support: Send photos in mobile messages with gallery picker, preview, and validation
Enhanced Mobile UI: Profile images in conversation list, automatic read marking, and visual unread indicators
Cross-Platform Consistency: Unified messaging experience across web and mobile platforms

Dark Mode System

Complete Theme Support: Light and dark themes across all screens and components
User Preferences: Toggle dark mode in Settings with persistent storage in database
Synchronized Experience: Dark mode preference shared between web and mobile platforms
Tailwind CSS Integration: Class-based dark mode with proper color schemes
Theme Context: React context providers for consistent theme management
Automatic Persistence: User preferences automatically saved and restored on app launch
Professional Design: Carefully crafted dark color palette with proper contrast ratios
Smooth Transitions: Instant theme switching with optimistic updates

Email System (Verification & Password Recovery)

6-Digit Codes: User-friendly numeric codes for both email verification and password reset
Email Verification: Required at signup with 24-hour expiration and beautiful templates
Password Recovery: Secure password reset with 1-hour expiration codes
SendGrid Integration: Professional email delivery with beautiful HTML templates and branding
Mobile-First Design: Optimized for easy code entry on mobile devices with numeric keypad
Automatic Navigation: Seamless flow between verification and authentication screens
Secure Token Generation: Cryptographically secure random number generation
Token Invalidation: Previous codes automatically invalidated when new ones are requested
Cross-Platform Support: Works on both web and mobile with consistent user experience
Dedicated UI Pages: User-friendly verification required pages with resend functionality
Error Handling: Comprehensive error handling with helpful user guidance

🚀 Redis Caching System

Yapplr features a comprehensive Redis-based caching system that dramatically improves performance for count operations and frequently accessed data.

Core Features

Count Caching: High-performance caching for followers, following, posts, likes, comments, reposts, and notifications
Smart Expiration: Optimized cache expiration times based on data volatility (2-15 minutes)
Automatic Invalidation: Cache automatically invalidated when data changes (posts, likes, follows, etc.)
Graceful Fallback: Automatic fallback to memory caching if Redis is unavailable
Type-Safe Operations: Strongly-typed caching with JSON serialization for complex data structures

Performance Benefits

50-80% faster user profile loads with cached follower/following counts
40-60% faster post feed rendering with cached like/comment counts
70-90% faster notification count queries
60-80% reduction in database queries for count operations
Sub-millisecond cache response times vs 10-100ms+ database queries

Technical Implementation

Redis 7.2: Latest Redis with optimized memory management and persistence
LRU Eviction: Automatic eviction of least recently used keys when memory limits reached
Data Persistence: Redis data survives container restarts with configurable save intervals
Health Monitoring: Comprehensive health checks and error logging
Memory Limits: Configurable memory limits (256MB staging, 512MB production)

Cache Categories

User Counts (10-minute expiration)

Follower count: count:followers:{userId}
Following count: count:following:{userId}
Post count: count:posts:{userId}

Post Counts (5-minute expiration)

Like count: count:likes:{postId}
Comment count: count:comments:{postId}
Repost count: count:reposts:{postId}

Notification Counts (2-minute expiration)

Unread notifications: count:notifications:unread:{userId}
Unread messages: count:messages:unread:{userId}

Tag Counts (15-minute expiration)

Tag post count: count:tag:posts:{tagId}
Tag post count by name: count:tag:posts:name:{tagName}

Configuration

{
  "Redis": {
    "ConnectionString": "redis:6379",
    "DefaultExpiration": "00:05:00"
  }
}

Deployment

Development: Redis on localhost:6379
Docker Local: Redis container on port 6380
Staging/Production: Redis containers with persistent volumes
External Redis: Easy switch to managed Redis services (AWS ElastiCache, Azure Redis)

⚡ Performance Optimizations

Database Performance

The application includes comprehensive database performance optimizations:

Strategic Indexing: Performance-optimized indexes for all critical query patterns
Timeline Queries: Composite indexes for efficient post retrieval with date ordering
User Profiles: Optimized indexes for user post queries with privacy filtering
Comment System: Fast comment loading with PostId+CreatedAt indexing
Message History: Efficient conversation message retrieval with proper indexing
Notification System: Optimized notification queries with user+date composite indexes
Online Status: Indexed LastSeenAt for fast online user queries
Following Lists: Efficient following relationship queries with proper indexing

Query Performance Improvements

10-100x faster timeline loading with optimized date ordering
Efficient user profile queries combining user filtering and date sorting
Optimized comment loading for post discussions
Faster message pagination in conversations
Improved notification performance for real-time updates

See Database Performance Analysis for detailed technical information.

🔧 Development

Configuration Management

The project includes powerful configuration management tools for easy testing and deployment:

# Quick notification provider switching
npm run config:platform-optimized  # SignalR web + Firebase mobile (recommended)
npm run config:signalr-only        # SignalR only (great for web testing)
npm run config:firebase-only       # Firebase only (mobile-focused)
npm run config:both                # Both providers (maximum coverage)
npm run config:none                # Polling only (baseline testing)

# Check current configuration
npm run config:status

# Manual configuration script
node configure-notifications.js [option]

The configuration system automatically updates both frontend and backend settings, making it easy to test different notification strategies without manual file editing.

Database Migrations

# Create new migration
dotnet ef migrations add MigrationName

# Migrations run automatically at application startup
# No manual database update needed - just restart the API
dotnet run

Automatic Migration System: Database migrations now run automatically when the API starts, eliminating deployment issues and ensuring consistency across environments.

Environment Configuration

Backend (appsettings.json)

{
  "ConnectionStrings": {
    "DefaultConnection": "Host=localhost;Database=yapplr_db;Username=postgres;Password=postgres"
  },
  "JwtSettings": {
    "SecretKey": "your-secret-key",
    "Issuer": "Yapplr.Api",
    "Audience": "Yapplr.Frontend"
  }
}

Frontend (.env.local)

NEXT_PUBLIC_API_URL=http://localhost:5161

🔔 Notification Configuration

Yapplr features a sophisticated platform-aware notification system that automatically selects the best notification provider for each platform.

Platform-Optimized Strategy

Web/Desktop: SignalR WebSocket notifications for instant real-time delivery
Mobile: Firebase push notifications for battery-efficient delivery even when app is closed
Automatic Detection: Platform detection automatically selects the optimal provider

Quick Configuration

# Platform-optimized (recommended)
npm run config:platform-optimized

# Test individual providers
npm run config:signalr-only     # SignalR only
npm run config:firebase-only    # Firebase only
npm run config:both            # Both providers
npm run config:none            # Polling only

# Check current configuration
npm run config:status

Environment Variables

# Platform-Specific Configuration
NEXT_PUBLIC_ENABLE_FIREBASE_WEB=false      # Firebase for web
NEXT_PUBLIC_ENABLE_SIGNALR=true            # SignalR for web
NEXT_PUBLIC_ENABLE_FIREBASE=true           # Firebase for mobile
NEXT_PUBLIC_ENABLE_SIGNALR_MOBILE=false    # SignalR for mobile

Backend Configuration

{
  "NotificationProviders": {
    "Firebase": {
      "Enabled": true,
      "ProjectId": "your-firebase-project-id"
    },
    "SignalR": {
      "Enabled": true,
      "MaxConnectionsPerUser": 10
    }
  }
}

Testing

Visit /notification-test to:

View platform detection results
Check active notification providers
Send test notifications
Monitor provider behavior

For detailed configuration options, see PLATFORM_SPECIFIC_NOTIFICATIONS.md.

📚 API Documentation

Authentication Endpoints

POST /api/auth/register - Register new user
POST /api/auth/login - Login user
POST /api/auth/forgot-password - Request password reset
POST /api/auth/reset-password - Reset password with token

Social Features

GET /api/posts/{id} - Get individual yap by ID (for sharing)
GET /api/posts/timeline - Get timeline with yaps and reyaps (paginated, 25 per page)
GET /api/posts/public - Get public timeline (paginated, 25 per page)
GET /api/posts/user/{userId}/timeline - Get user timeline (yaps + reyaps, paginated)
POST /api/posts - Create new yap with optional image attachment
POST /api/posts/{id}/repost - Reyap a yap
DELETE /api/posts/{id}/repost - Remove reyap
POST /api/posts/{id}/like - Like a yap
DELETE /api/posts/{id} - Delete your own yap

Image Management

POST /api/images/upload - Upload image file (JPG, PNG, GIF, WebP, max 5MB)
GET /api/images/{fileName} - Serve uploaded image with proper content type
DELETE /api/images/{fileName} - Delete uploaded image (authorized users only)

Comments System

GET /api/posts/{id}/comments - Get all comments for a specific yap
POST /api/posts/{id}/comments - Add a new comment to a yap
PUT /api/posts/comments/{commentId} - Update your own comment
DELETE /api/posts/comments/{commentId} - Delete your own comment

Hashtag System

GET /api/tags/search/{query} - Search for hashtags with optional limit parameter
GET /api/tags/trending - Get trending hashtags based on recent activity
GET /api/tags/{tagName} - Get specific hashtag information and post count
GET /api/tags/{tagName}/posts - Get all posts containing a specific hashtag (paginated)
GET /api/tags/analytics/trending - Get trending hashtags with analytics (days and limit parameters)
GET /api/tags/analytics/top - Get top hashtags by total post count
GET /api/tags/{tagName}/analytics - Get detailed analytics for a specific hashtag
GET /api/tags/{tagName}/usage - Get hashtag usage over time (daily breakdown)

User Management

GET /api/users/{username} - Get user profile
PUT /api/users/me - Update current user's profile (bio, pronouns, tagline, birthday)
POST /api/users/{userId}/follow - Follow user (creates follow request if approval required)
DELETE /api/users/{userId}/follow - Unfollow user
GET /api/users/me/following - Get users that current user is following
GET /api/users/me/followers - Get users that are following the current user
GET /api/users/{userId}/following - Get users that a specific user is following
GET /api/users/{userId}/followers - Get users that are following a specific user
GET /api/users/me/following/online-status - Get following users with their online status
POST /api/users/me/profile-image - Upload profile image

Follow Request System

GET /api/users/follow-requests - Get pending follow requests for current user
POST /api/users/follow-requests/{requestId}/approve - Approve a follow request
POST /api/users/follow-requests/{requestId}/deny - Deny a follow request
POST /api/users/follow-requests/approve-by-user/{requesterId} - Approve follow request by requester user ID
POST /api/users/follow-requests/deny-by-user/{requesterId} - Deny follow request by requester user ID

Blocking System

POST /api/blocks/users/{userId} - Block a user
DELETE /api/blocks/users/{userId} - Unblock a user
GET /api/blocks/users/{userId}/status - Check if user is blocked
GET /api/blocks - Get list of blocked users

Private Messaging

POST /api/messages - Send new message (creates conversation if needed)
POST /api/messages/conversation - Send message to existing conversation
GET /api/messages/conversations - Get user's conversations (paginated, 25 per page)
GET /api/messages/conversations/{id} - Get specific conversation details
GET /api/messages/conversations/{id}/messages - Get messages in conversation (paginated, 25 per page)
POST /api/messages/conversations/{id}/read - Mark conversation as read
GET /api/messages/can-message/{userId} - Check if current user can message another user
POST /api/messages/conversations/with/{userId} - Get or create conversation with user
GET /api/messages/unread-count - Get total count of unread messages across all conversations

Notifications System

GET /api/notifications - Get user notifications (paginated, 25 per page)
GET /api/notifications/unread-count - Get count of unread notifications
PUT /api/notifications/{id}/read - Mark specific notification as read
PUT /api/notifications/read-all - Mark all notifications as read for user

User Preferences

GET /api/preferences - Get current user's preferences (dark mode, etc.)
PUT /api/preferences - Update user preferences with partial updates

User Reporting System

POST /api/reports - Create user report for objectionable content (posts or comments)
GET /api/reports/my-reports - Get current user's submitted reports (paginated)
GET /api/admin/system-tags - Get system tags for report categorization

🔒 Security Features

Password Hashing: BCrypt with salt rounds
JWT Tokens: Secure authentication with 60-minute expiration
Token Expiration Handling: Automatic detection and seamless login redirection when tokens expire
Email Verification: Required email verification to prevent bot registrations
Password Recovery: Secure 6-digit code system with 1-hour expiration and token invalidation
Email Security: SendGrid integration with professional email templates and reliable delivery
CORS Configuration: Properly configured for frontend development
Input Validation: Comprehensive validation on all endpoints
Privacy Controls: Robust privacy system with relationship-based filtering
Environment-Based Security: Test and debug endpoints are conditionally registered based on environment
- Development-Only Endpoints: Debug, test, and cache management endpoints only available in development
- Production Security: Test endpoints (/api/notifications/test-*, /api/cqrs-test/*, debug endpoints) are automatically disabled in production
- Swagger/OpenAPI: API documentation only accessible in development and staging environments
- Mobile App Security: Debug and test screens in mobile app only accessible in development builds

🚀 Deployment

The platform includes automated deployment scripts that handle all services including the AI content moderation system.

Staging Deployment

# Deploy to staging environment
./deploy-stage.sh

Production Deployment

# Deploy to production environment
./deploy-prod.sh

Both deployment scripts automatically:

Build and deploy the .NET API
Build and deploy the Next.js frontend
Build and deploy the AI content moderation service
Set up nginx with SSL termination
Configure PostgreSQL database
Run database migrations
Perform health checks on all services

Service Architecture

The deployment includes these containerized services:

yapplr-api: Main .NET API service
yapplr-frontend: Next.js web application
content-moderation: Python AI moderation service
postgres: PostgreSQL database
nginx: Reverse proxy with SSL termination

See individual README files for detailed deployment instructions:

🆕 Recent Updates

Emoji Reaction System (Latest)

Rich Reactions: Replaced simple likes with 6 emoji reaction types (❤️👍😂😮😢😡)
Interactive UI: New reaction picker with hover effects and real-time counts
Database Migration: Automatic conversion of existing likes to heart reactions
Full Coverage: Reactions available for both posts and comments
Mobile Support: Complete React Native implementation with modal picker
Admin Interface: Updated admin views to show reaction breakdowns
Backward Compatibility: Maintains existing like functionality during transition

📄 License

This project is open source and available under the MIT License.

🤝 Contributing

Fork the repository
Create a feature branch
Make your changes
Add tests if applicable
Submit a pull request

📞 Support

For questions or issues, please open a GitHub issue or contact the development team.

Name		Name	Last commit message	Last commit date
.expo		.expo
.github/workflows		.github/workflows
Documents		Documents
Yapplr.Api.Tests		Yapplr.Api.Tests
Yapplr.Api		Yapplr.Api
Yapplr.Shared		Yapplr.Shared
Yapplr.VideoProcessor.Tests		Yapplr.VideoProcessor.Tests
Yapplr.VideoProcessor		Yapplr.VideoProcessor
YapplrMobile		YapplrMobile
analytics		analytics
config/rabbitmq		config/rabbitmq
design-docs		design-docs
docs		docs
scripts		scripts
sentiment-analysis		sentiment-analysis
yapplr-frontend		yapplr-frontend
yapplr-shared		yapplr-shared
.env.example		.env.example
.gitignore		.gitignore
ADMIN_ANALYTICS_INFLUXDB_GUIDE.md		ADMIN_ANALYTICS_INFLUXDB_GUIDE.md
ANALYTICS_COMPLETION_SUMMARY.md		ANALYTICS_COMPLETION_SUMMARY.md
ANALYTICS_MIGRATION_GUIDE.md		ANALYTICS_MIGRATION_GUIDE.md
ANALYTICS_SETUP.md		ANALYTICS_SETUP.md
CODEGRAPH.md		CODEGRAPH.md
GROUP_DEPLOYMENT_GUIDE.md		GROUP_DEPLOYMENT_GUIDE.md
GROUP_IMPLEMENTATION_SUMMARY.md		GROUP_IMPLEMENTATION_SUMMARY.md
GROUP_TESTING_CHECKLIST.md		GROUP_TESTING_CHECKLIST.md
HANDBRAKE_MIGRATION_GUIDE.md		HANDBRAKE_MIGRATION_GUIDE.md
MOBILE_VIDEO_URL_FIX.md		MOBILE_VIDEO_URL_FIX.md
OPTIMIZED_DEPLOYMENT_README.md		OPTIMIZED_DEPLOYMENT_README.md
PAYMENT_GATEWAY_CONFIGURATION.md		PAYMENT_GATEWAY_CONFIGURATION.md
README.md		README.md
STAGING_ANALYTICS_SETUP.md		STAGING_ANALYTICS_SETUP.md
VIDEO_PROCESSING_IMPLEMENTATION_SUMMARY.md		VIDEO_PROCESSING_IMPLEMENTATION_SUMMARY.md
VIDEO_URL_DEBUGGING_SUMMARY.md		VIDEO_URL_DEBUGGING_SUMMARY.md
Yapplr.sln		Yapplr.sln
check-deployment-status-prod.sh		check-deployment-status-prod.sh
check-deployment-status.sh		check-deployment-status.sh
configure-notifications.js		configure-notifications.js
debug-connection-string.sh		debug-connection-string.sh
debug-prod-db-connection.sh		debug-prod-db-connection.sh
debug-staging-api.sh		debug-staging-api.sh
deploy-prod-optimized.sh		deploy-prod-optimized.sh
deploy-prod.sh		deploy-prod.sh
deploy-stage-optimized.sh		deploy-stage-optimized.sh
deploy-stage.sh		deploy-stage.sh
diagnose-rabbitmq-disk.sh		diagnose-rabbitmq-disk.sh
docker-compose.local.yml		docker-compose.local.yml
docker-compose.prod.yml		docker-compose.prod.yml
docker-compose.stage.yml		docker-compose.stage.yml
docker-compose.yml		docker-compose.yml
fix-rabbitmq-disk-space.sh		fix-rabbitmq-disk-space.sh
force-rebuild-prod.sh		force-rebuild-prod.sh
force-rebuild.sh		force-rebuild.sh
generate-secure-password.sh		generate-secure-password.sh
monitor.sh		monitor.sh
nginx.conf		nginx.conf
nginx.stage.conf		nginx.stage.conf
package-lock.json		package-lock.json
package.json		package.json
rebuild-all.sh		rebuild-all.sh
rebuild.sh		rebuild.sh
test-optimization.sh		test-optimization.sh
test_rotation_detection.py		test_rotation_detection.py
verify-analytics-build.sh		verify-analytics-build.sh
yapplr-128.png		yapplr-128.png
yapplr-32.png		yapplr-32.png
yapplr-64.png		yapplr-64.png
yapplr.png		yapplr.png
yapplr_icon.svg		yapplr_icon.svg

Latest commit

History

Folders and files

Repository files navigation

Yapplr - Twitter-like Social Media Platform

🚀 Features

Core Social Features

👥 Groups & Communities

🛡️ Admin & Moderation System

💳 Subscription System & Payment Gateways

Privacy & Security

User Experience

📸 Photo Library & Multi-Media Features

🎥 Video Features

🛠 Tech Stack

Backend (.NET 9 API)

Content Moderation Service (Python)

Frontend (Next.js 15)

Mobile App (React Native + Expo)

🏷️ Hashtag System

Core Features

User Interface

Technical Implementation

API Endpoints

📸 Photo Library & Multi-Media API

Core Features

API Endpoints

Multi-Media Post Creation

Photo Library

Media Processing

Technical Implementation

👥 Groups & Communities API

Core Features

API Endpoints

Group Management

Group Membership

Group Content

Technical Implementation

🤖 AI Content Moderation System

Core Features

Content Categories

Content Warnings

Violations

Technical Implementation

Configuration Options

Admin Integration

API Endpoints

🎯 User Trust Score System

Core Features

Trust Score Factors

Positive Factors (Increase Trust)

Negative Factors (Decrease Trust)

Trust-Based Features

Content Visibility Levels

Action Thresholds

Rate Limiting Multipliers

Technical Implementation

Admin Features

Configuration Options

API Endpoints

💳 Payment Gateway Configuration & Subscription System

Core Features

Subscription Tiers

Payment Provider Configuration

Admin Interface Features

Supported Providers

API Endpoints

Subscription Management

Payment Processing

Admin Configuration

Admin Subscription Management

Technical Implementation

Configuration Options

🚦 Smart API Rate Limiting

Core Features

Rate Limit Configuration

Base Rate Limits (per operation type)

Trust Score Multipliers

Violation Handling

Exempt Endpoints