Smart Contracts

Overview

The InkDAO platform smart contracts enable a decentralized content publishing and monetization platform. Creators publish content to IPFS with access controlled through blockchain-verified ownership. The platform uses ERC-6909 multi-token standard to manage all posts within a single contract, eliminating the need for deploying individual token contracts per post.

Architecture

The platform consists of two core contracts working together to create a seamless content monetization system:

Core Contracts

  1. MarketPlace - Central hub using ERC-6909 for post creation, subscriptions, and platform logic

  2. DXconfig - Configuration management and access control

ERC-6909 Multi-Token Standard

Why ERC-6909?

  • Gas Efficiency: No contract deployment per post (massive gas savings)

  • Simplified Architecture: Single contract manages all posts

  • Scalability: Unlimited posts without deploying new contracts

  • Token IDs: Each post is identified by a unique token ID

  • Non-Transferable: Tokens are soul-bound to subscribers (access rights cannot be traded)

How They Work Together

Creator → MarketPlace.createPost() → Token ID assigned + Metadata stored
                                              ↓
Reader → MarketPlace.subscribePost() → Payment to Creator + Token minted to Reader
                                              ↓
                                        DXconfig (stores configuration)

Publishing Flow:

  1. Creator uploads content to IPFS (private)

  2. Creator calls createPost() with metadata and price

  3. MarketPlace assigns unique token ID and stores metadata on-chain

  4. PostCreated event emitted with token ID and CID

  5. Post visible on platform

Subscription Flow:

  1. Reader finds post on platform

  2. Reader calls subscribePost(tokenId) with payment

  3. Payment goes directly to creator's wallet

  4. ERC-6909 token minted to reader (1 unit of tokenId)

  5. Backend verifies token balance via balanceOf(reader, tokenId)

  6. Full content served from IPFS

Deployed Contracts

The following contracts are currently deployed:

Contract
Network
Address

DXconfig

Sepolia

TBD

MarketPlace

Sepolia

TBD

Note: With ERC-6909, all posts are managed within the single MarketPlace contract. Each post is identified by a unique token ID rather than having its own contract address.

Key Features

Content Monetization

  • Creator-Set Pricing: Each post has individual pricing in native currency (ETH/MATIC)

  • Direct Payments: 100% to creator's wallet, no intermediaries

  • Lifetime Access: One-time subscription for permanent access rights

  • Tokenized Ownership: Access proven through ERC-6909 token balance

  • Non-Transferable: Soul-bound tokens prevent resale of access rights

Technical Features

  • ERC-6909 Multi-Token: All posts managed in one contract with unique token IDs

  • Gas Efficient: Eliminates costly contract deployment per post

  • Upgradeable: Uses proxy pattern for future improvements

  • Pausable: Emergency stop mechanism for security

  • Access Control: Role-based permissions (Admin)

  • Event Logging: Comprehensive event emission for indexing

  • Token Supply Tracking: Built-in supply management per token ID

Security Features

  • Reentrancy protection on all state-changing functions

  • Input validation and sanity checks (title length, description, price limits)

  • Pausable functionality for emergencies

  • Zero address checks

  • Native transfer validation with revert on failure

  • Direct payments to creators - no intermediaries

  • Non-transferable tokens prevent unauthorized access trading

  • Duplicate subscription prevention

Technology Stack

  • Solidity: ^0.8.21

  • OpenZeppelin: Upgradeable contracts, ERC-6909, Access Control

  • Foundry: Development and testing framework

  • ERC-6909: Multi-token standard for efficient token management

Configuration Parameters

  • Max Post Title Length: Character limit for post titles

  • Max Description Length: Character limit for descriptions

  • Max Price In Native: Maximum allowed price per post

  • Payment Model: Direct payments to creators, no platform fees

Token ID System

Each post is assigned a unique token ID starting from 1:

  • Token IDs are sequential and auto-incrementing

  • Token ID 0 is reserved/invalid

  • Mapping from CID to Token ID for lookups

  • Each subscriber receives 1 unit of the token ID

See individual contract documentation:

PreviousWebhooksNextMarketPlace

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