meta-tx

Overview

ink! Meta transaction contract implementations. Contracts are implemented based on the ERC2771 specifications. Corresponding solidity implementations can be found here.

Forwarder contract - Forwarder contracts verify signers' signature and forward transaction requests to actual callee contracts. MetaTxContext crate - Callee contracts which want to make use of signers' information need to implements MetaTxContext trait. Registry contract - An example contract implementing MetaTxContext.

How to test

1. Run local node e.g. swanky-node
2. Install dependencies. yarn.
3. Test. yarn test.

Original forwarder contract implementation with no MetaTxContract can be found here. The Forwarder contract in this reposiroty is referencing to original implementation, and small modifications were added to it.

How to use MetaTxContext

1. Import meta-tx-context crate.
2. Use crate and implement MetaTxContext trait.

use meta_tx_context::*;

impl MetaTxContext for Contract {}

3. Take Uint8 Vec Vec<u8> as the last argment of messages. For example,

pub fn register(&mut self, name: String, data: Vec<u8>) -> Result<(), Error> {}

This is needed to decode call inputs which cotains Signer's AccountId as the extra 32bytes attached by Forwarder contract.

4. Use self._caller(data) instead of self.env().caller().