SwapDex App

Overview

SwapDex is a decentralized mobile application built using React Native and web3 libraries. The app enables users to swap cryptocurrencies across different networks with a seamless and efficient onboarding process. It also allows users to:

• View transaction history
• Check balances
• See the top 100 tokens
• Read the latest crypto news

The swap functionality is powered by 1inch API and Chainlink price feeds, while Alchemy is used as the RPC provider.

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Features

1. Onboarding Process

• Wallet connection via Reown.

2. Swap Interface

• Users can select tokens to swap.
• Price feeds fetched via Chainlink.
• Allowance checking before initiating swaps.
• Users can edit slippage settings.
• Handles slippage errors and transaction failures.

3. Transaction Handling

• Uses ethers.js for transaction formatting.
• Converts token amounts based on decimals (e.g., 18 for ETH, varies for ERC20 tokens).
• Handles errors like exceeding API rate limits and incorrect amount conversions.

4. UI Components

• Top UI: Displays ETH/Polygon balance and USD equivalent.
• Network switcher: Toggle between ETH and Polygon.
• Tokens Screen: View top 100 tokens.
• Latest Transactions Screen: View transaction history.
• News Screen: Displays latest crypto news.
• Transaction Hash Screen:
  • Displays transaction confirmation.
  • Allows users to click and view transactions on Etherscan/Polygonscan.

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Technologies Used

• Expo React Native
• WAGMI, Viem & ethers.js for onchain interactions
• Alchemy RPC Provider & Alchemy SDK
• 1inch API for swapping
• React Query (for caching and data fetching)
• Chainlink API for price feeds
• Cryptocompare API for news
• Coinranking API for the top token list
• Reown for wallet integration
• Custom Hooks for modular and reusable code

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Key Issues Addressed

1. Handling API Rate Limits

• Implemented refetch and increased request interval to prevent exceeding 1inch API limits.
• Added custom slippage settings for better user control.

2. Error Handling & Debugging

• Displaying error messages in the UI instead of console logs.
• Handling high slippage errors, invalid swaps, and failed API requests.
• Improved UI/UX feedback for failed swaps.

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🚀 SwapDex is designed to offer a seamless, decentralized swapping experience with reliable price feeds, secure wallet connections, and a smooth UI.
Happy swapping! 🦄💰