Comment Service - Disqus-like Comment System

A serverless comment-as-a-service built with SST, supporting rich text comments, threaded replies, and API key authentication.

Architecture Overview

Technology Stack

• Backend: SST (Serverless Stack) with AWS Lambda
• Database: DynamoDB for comments and metadata
• Authentication: API Key-based authentication
• Frontend: React with TypeScript
• Rich Text: Support for markdown and HTML content
• Deployment: AWS (Lambda, DynamoDB, S3, CloudFront)

Core Features

• ✅ API key authentication
• ✅ Rich text comments (markdown/HTML)
• ✅ Threaded replies

Database Design

Tables

Comments Table

interface Comment {
  id: string;                    // UUID
  threadId: string;              // Thread identifier (e.g., article URL)
  parentId?: string;             // For replies (null for top-level)
  content: string;               // Rich text content
  author: {
    name: string;
    email: string;
  };
  createdAt: string;             // ISO timestamp
}

Threads Table

interface Thread {
  id: string;                    // Thread identifier
  title: string;                 // Page/article title
  url: string;                   // Page URL
  lastCommentAt?: string;
  settings: {
    allowReplies: boolean;
    maxDepth: number;            // Max reply depth
  };
}

API Design

Authentication

All API requests require an X-API-Key header with a valid API key.

Endpoints

Comments

• GET /api/comments/{threadId} - Get comments for a thread
• POST /api/comments - Create a new comment
• PUT /api/comments/{commentId} - Update a comment
• DELETE /api/comments/{commentId} - Delete a comment

Threads

• GET /api/threads/{threadId} - Get thread information
• POST /api/threads - Create a new thread
• PUT /api/threads/{threadId} - Update thread settings

Response Format

interface ApiResponse<T> {
  data?: T;
  error?: {
    code: string;
    message: string;
  };
  pagination?: {
    nextPageToken?: string;
  };
}

Deployment

The application will be deployed using SST to AWS with:

• Lambda functions for API endpoints
• DynamoDB for data storage
• S3 + CloudFront for static assets
• API Gateway for HTTP routing