ethcontract-rs

Crate used for generating code for Ethereum smart contracts. It provides a function procedural macro that generates safe bindings for contract interaction based on the contract ABI.

Getting Started

Add a dependency to the ethcontract crate in your Cargo.toml:

[dependencies]
ethcontract = "..."

Then generate a struct for interacting with the smart contract with a type-safe API:

ethcontract::contract!("path/to/truffle/build/contract/Contract.json");

This will generate a new struct ContractName with contract generated methods for interacting with contract functions in a type-safe way.

Minimum Supported Rust Version

The minimum supported Rust version is 1.42.

Generator API

As an alternative to the procedural macro, a generator API is provided for generating contract bindings from build.rs scripts. More information can be found in the ethcontract-generate README.

Running the Examples

In order to run local examples you will additionally need:

• NodeJS
• Yarn

For all examples, the smart contracts must first be built:

cd examples/truffle
yarn && yarn build

Truffle Examples

Truffle examples rely on the local truffle development server. In a separate terminal run:

cd examples/truffle
yarn start

• The abi example deploys a simple contract and performs various eth_calls to illustrate how Solidity types are mapped to Rust types by ethcontract.

  cargo run --example abi
  

• The async example deploys an ERC20 token and interacts with the contract with various accounts.

  cargo run --example async
  

• The deployments example illustrates how the deployments parameter can be specified when generating a contract with the ethcontract::contract! macro. This can be useful for specifying addresses in testing environments that are deterministic but either not included, or inacurate in the artifact's networks property (when for example the contract is developed upstream, but a separte testnet deployment wants to be used).

  cargo run --example deployments
  

• The events example illustrates how to listen to logs emitted by smart contract events.

  cargo run --example events
  

• The generator example (actually a separate crate to be able to have a build script) demonstrates how the generator API can be used for creating type-safe bindings to a smart contract with a build.rs build script.

  cargo run --package examples-generate
  

• The linked example deploys a library and a contract that links to it and makes a method call.

  cargo run --example linked
  

Rinkeby Example

There is a provided example that runs with Rinkeby and Infura. Running this example is a little more involved to run because it requires a private key with funds on Rinkeby (for gas) as well as an Infura project ID in order to connect to a node. Parameters are provided to the Rinkeby example by environment variables:

export PK="private key"
export INFURA_PROJECT_ID="Infura project ID"
cargo run --example rinkeby

Sources Example

This example generates contract bindings from online sources:

• A verfied contract on Etherscan
• An npmjs contract

It also queries some contract state with Infura. Running this example requires an Infura project ID in order to connect to a node. Parameters are provided to the example by environment variables:

export INFURA_PROJECT_ID="Infura project ID"
cargo run --example sources

Sample Contracts Documentation

We added some samples of generated contracts from our sample contract collection gated behind a feature. This feature is only intended to be used for document generation. In order to view the documentation for these contracts you need to first build the contracts and then generate documentation for the crate with the samples feature enabled:

(cd examples/truffle; yarn && yarn build)
cargo doc --features samples --open

This will open a browser at the documentation root. Look under the samples module for the sample contracts to get a feel for how the generated types look.