Idea: Meta-Transaction Relayer Contract

[sacha-l]

Meta-Transaction Relayer Contract

• 🚀 Track: Original Smart Contract Development

📝 Summary

Background

Meta-transactions allow users to sign messages off-chain that a relayer submits on their behalf, making transactions gasless from the user’s perspective. This improves onboarding by eliminating the need for users to hold native tokens.

Project Summary

Deploy a PolkaVM smart contract that validates EIP-712-style signed payloads and executes transactions on behalf of users. A trusted relayer pays gas and may be compensated separately.

💡 Value to Polkadot

Greatly improves UX for dApps on Polkadot by abstracting away gas fees. Encourages adoption by less technical users and unlocks new app experiences.

✅ Feasibility (MVP in 3 Days)

• Use OpenZeppelin’s MinimalForwarder pattern.
• Only support one method (e.g., setGreeting()) to demo flow.
• Deploy relayer script separately.

⚙️ Proposed Approach

1. Fork OpenZeppelin MinimalForwarder and target contract.
2. Add support for verifying and executing meta-tx.
3. Write a relayer script that signs and submits transactions.
4. Deploy to Westend and simulate one round.

📦 Deliverables

• Meta-tx enabled contract on Westend
• Relayer script repo
• README with:
  • Signature walkthrough
  • Demo transaction
  • Future extensions (fee market, whitelisting)