Self-custody wallet and token swap app
A self-custody mobile wallet for EVM networks with token swaps, transaction simulation, and plain-language warnings before users sign.
- Client
- Web3 startup
- Location
- Singapore
- Platforms
- iOS, Android
- Duration
- 16 weeks
- Team
- 4 engineers
The challenge
The client wanted a wallet that newcomers could use safely. Most of the risk sat at the moment of signing: users approved transactions they did not understand, and many skipped backing up their recovery phrase.
What we built
We built a React Native wallet with keys held in the device’s secure storage, a guided backup flow, and support for Ethereum and major layer-2 networks. Every transaction is simulated before signing and explained in plain language, swaps route through a DEX aggregator, and a small set of Solidity contracts handles fees, prepared for an independent audit.
Highlights
- Keys generated and stored on the device, never on a server
- Transaction simulation with human-readable previews
- Token swaps through an aggregator with slippage protection
- Ethereum, Arbitrum, Base and Polygon support
- Indexer for balances and history across networks
Technical stack
- Mobile
- React NativeTypeScriptethers.js
- Blockchain
- SolidityFoundryOpenZeppelin
- Backend
- Node.jsPostgreSQLRedis
- Infrastructure
- AWSDocker
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