web3

Ethereum JSON-RPC multi-transport client. Rust implementation of Web3.js library.

Documentation: crates.io

Status

Note this package is barely maintained and I am looking for an active maintainer (see #664). If you are starting a new project, I'd recommend choosing https://github.com/gakonst/ethers-rs instead.

Usage

First, add this to your Cargo.toml:

[dependencies]
web3 = "0.18.0"

Example

#[tokio::main]
async fn main() -> web3::Result<()> {
    let transport = web3::transports::Http::new("http://localhost:8545")?;
    let web3 = web3::Web3::new(transport);

    println!("Calling accounts.");
    let mut accounts = web3.eth().accounts().await?;
    println!("Accounts: {:?}", accounts);
    accounts.push("00a329c0648769a73afac7f9381e08fb43dbea72".parse().unwrap());

    println!("Calling balance.");
    for account in accounts {
        let balance = web3.eth().balance(account, None).await?;
        println!("Balance of {:?}: {}", account, balance);
    }

    Ok(())
}

If you want to deploy smart contracts you have written you can do something like this (make sure you have the solidity compiler installed):

solc -o build --bin --abi contracts/*.sol

The solidity compiler is generating the binary and abi code for the smart contracts in a directory called contracts and is being output to a directory called build.

For more see examples folder.

Futures migration

Get rid of parking_lot (replace with async-aware locks if really needed).
Consider getting rid of Unpin requirements. (#361)
WebSockets: TLS support (#360)
WebSockets: Reconnecting & Pings
Consider using tokio instead of async-std for ws.rs transport (issue with test).
Restore IPC Transport

General

More flexible API (accept Into<X>)
Contract calls (ABI encoding; debris/ethabi)
Batch Requests

Transports

HTTP transport
IPC transport
WebSockets transport

Types

Types for U256,H256,Address(H160)
Index type (numeric, encoded to hex)
Transaction type (Transaction from Parity)
Transaction receipt type (TransactionReceipt from Parity)
Block type (RichBlock from Parity)
Work type (Work from Parity)
Syncing type (SyncStats from Parity)

APIs

Parity-specific APIs

let web3 = Web3::new(transport);
web3.api::<CustomNamespace>().custom_method().wait().unwrap()

Installation on Windows

Currently, Windows does not support IPC, which is enabled in the library by default. To compile, you need to disable the IPC feature:

web3 = { version = "0.18.0", default-features = false, features = ["http"] }

Avoiding OpenSSL dependency

On Linux, native-tls is implemented using OpenSSL. To avoid that dependency for HTTPS use the corresponding feature.

web3 = { version = "0.18.0", default-features = false, features = ["http-rustls-tls"] }

Cargo Features

The library supports following features:

http - Enables HTTP transport (requires tokio runtime, because of hyper).
http-tls - Enables TLS support via reqwest/default-tls for HTTP transport (implies http; default).
http-native-tls - Enables TLS support via reqwest/native-tls for HTTP transport (implies http).
http-rustls-tls - Enables TLS support via reqwest/rustls-tls for HTTP transport (implies http).
ws-tokio - Enables WS transport using tokio runtime.
ws-tls-tokio - Enables TLS support for WS transport (implies ws-tokio; default).
ws-async-std - Enables WS transport using async-std runtime.
ws-tls-async-std - Enables TLS support for WS transport (implies ws-async-std).
ipc-tokio - Enables IPC transport using tokio runtime (default).
signing - Enable account namespace and local-signing support (default).
eip-1193 - Enable EIP-1193 support.
wasm - Compile for WASM (make sure to disable default features).
arbitrary_precision - Enable arbitrary_precision in serde_json.
allow-missing-fields - Some response fields are mandatory in Ethereum but not present in EVM-compatible chains such as Celo and Fantom. This feature enables compatibility by setting a default value on those fields.

popzxc/rust-web3