Idea: Substrate & EVM Hybrid DApp Toolkit

[sacha-l]

Substrate & EVM Hybrid DApp Toolkit

• 🛠 Track: Smart Contract Development Tools

📝 Summary

Background

Polkadot dApps can combine runtime (Substrate) features with EVM-based contracts on PolkaVM. However, developers typically need to stitch together Polkadot API or Polkadot.js and ethers.js/viem manually. This project aims to simplify hybrid dApp development.

Project Summary

Develop a toolkit or library that exposes common utilities for interacting with both Substrate pallets (via the Polkadot API) and EVM contracts (via ethers or viem) in a single frontend. Include wallet connection logic, unified account handling, and examples.

💡 Value to Polkadot

Bridges the tooling gap between Polkadot-native features (like governance, staking, or identity) and EVM-compatible smart contracts. Makes hybrid applications easier to build and maintain.

✅ Feasibility (MVP in 3 Days)

• Focus on a handful of utility functions (e.g. read native balance, call contract)
• Use known libraries (ethers + papi or polkadot.js)
• Provide demo frontend for test interaction

⚙️ Proposed Approach

1. Create a JS/TS utility library that exports functions:
   • getPolkadotBalance()
   • getEvmTokenBalance()
   • sendContractTx()
   • fetchSubstrateEvents()
2. Set up unified wallet connection using Talisman or MetaMask
3. Build a demo React UI to showcase both types of interactions
4. Document integration examples

📦 Deliverables

• NPM package or GitHub repo with utility lib
• Demo frontend or Storybook-style demo
• README with:
  • Setup steps
  • Example hybrid calls
  • Known caveats