dart_web3_price

License: MIT

A real-time asset pricing engine for the Web3 stack. Integrate market data from leading centralized and decentralized sources to provide accurate valuation of crypto assets.

🚀 Features

  • Decentralized Oracles: Direct support for Chainlink and Uniswap V3 TWAP oracles.
  • Centralized APIs: Native adapters for CoinGecko, CoinMarketCap, and Binance.
  • Precision Mapping: Maps asset symbols to native Coingecko IDs automatically.
  • Historical Data: Fetch OHLCV data for charts and portfolio analysis (planned).

Usage Flow

graph TD
    A[Token Symbol] --> B[PriceHub]
    B --> C{Strategy?}
    C -->|API| D[CoinGecko / Binance]
    C -->|On-Chain| E[Chainlink Oracle]
    D --> F[Result Conversion]
    E --> F
    F --> G[Cached TokenPrice]

🏗️ Architecture

graph TD
    App[Price Display] --> Hub[Price Hub]
    
    subgraph Oracles [On-Chain]
        Chainlink[Chainlink Client]
    end
    
    subgraph APIs [Off-Chain]
        Gecko[CoinGecko Adapter]
    end
    
    Hub --> Oracles
    Hub --> APIs

📚 Technical Reference

Core Classes

Class Responsibility
PriceHub The main interface for fetching and caching asset prices.
PriceSource Abstract interface for implementing new data providers.
TokenPrice Container for price, timestamp, and source metadata.
CurrencyCode (Enum) Supported fiat and crypto base denominations.

🛡️ Security Considerations

  • Oracle Manipulation: On-chain prices can be manipulated via flash loans. Always use TWAP or decentralized aggregators for critical DeFi logic.
  • Fallback Logic: API-based pricing can go down. The SDK allows setting primary and fallback sources to ensure UI continuity.
  • Staleness Threshold: Check the timestamp of the returned price. In production, reject prices older than 5-10 minutes for active trading components.

💻 Usage

Multi-Source Price Fetching

import 'package:dart_web3_price/dart_web3_price.dart';

void main() async {
  final hub = PriceHub(primary: CoinGeckoSource());

  // Fetch ETH price in USD
  final price = await hub.getPrice(asset: 'ethereum', currency: 'usd');
  
  print('Current Price: $${price.value}');
  print('Source: ${price.sourceName}');
}

📦 Installation

dependencies:
  dart_web3_price: ^0.1.0

Libraries

web3_universal_price