EVM → NEAR

evm2near is a project for compiling EVM bytecode into wasm bytecode, with the particular goal of having that wasm artifact be executable on the NEAR blockchain. For ease of testing locally, evm2near also currently supports wasi as a target platform. The wasi output can be run locally using a wasm runtime, for example wasmtime. This can be useful for debugging contracts without deploying to NEAR.

Even though evm2near is a general EVM bytecode to wasm bytecode transpiler, the CLI interface accepts a Solidity source file as input for convenience. The source file is compiled to EVM bytecode using solc. Using Solidity and solc, means evm2near also has access to the contract ABI. This allows the output wasm artifact to contain functions that match the ones given in the contract. For example, test/calc.sol contains a contract with a function multiply(int a, int b), and the compiled wasm artifact will also contain a function called multiply which takes a JSON string as input. The JSON input is expected to be an object with fields matching the function argument names (a and b in the example). These functions generated based on the ABI are in addition to a general function called execute, which accepts binary input following the usual Solidity ABI (i.e. the first four bytes are the "selector" derived from the function signature, the remaining bytes are the input arguments encoded using Solidity's ABI format).

Usage

Compiling to wasi (for running locally)

./evm2near INPUT_SOLIDITY_CONTRACT -o OUTPUT_WASM_FILE -b wasi

Example:

./evm2near test/calc.sol -o calc.wasm -b wasi

Running the output in wasmtime:

wasmtime --allow-unknown-exports calc.wasm --invoke multiply -- '{"a":6, "b": 7}'

Compiling to NEAR

./evm2near INPUT_SOLIDITY_CONTRACT -o OUTPUT_WASM_FILE -b near

Example:

./evm2near test/calc.sol -o calc.wasm -b near

Running the output using near-cli:

near --networkId testnet dev-deploy calc.wasm
near --networkId testnet --accountId $NEAR_ACCOUNT_ID call $DEV_CONTACT_ID multiply '{"a": 7, "b": 6}'

Note: you will need to set the value of $DEV_CONTACT_ID from the output of the prior dev-deploy command (you will see something like Account id: dev-1663014663747-27418521013742 included in the output, then you would set DEV_CONTACT_ID=dev-1663014663747-27418521013742).

Note: you will need to use your own NEAR account for $NEAR_ACCOUNT_ID. If you do not have one, you can create it using the NEAR wallet, then access it via the CLI using the near login command.

Help

./evm2near --help

Development

Prerequisites

• Rust toolchain (nightly 2022-09-07)
• Solidity compiler solc (0.8.16+)
• wasm-strip from WABT

Prerequisites on macOS

brew install rustup solidity wabt

Prerequisites on Ubuntu

curl -sSf https://sh.rustup.rs | sh

sudo apt-add-repository ppa:ethereum/ethereum
sudo apt update
sudo apt install solc

sudo apt install wabt

Development Builds

rustup target add wasm32-wasi
rustup target add wasm32-unknown-unknown
make
./evm2near --help

Release

Prerequisites

• Rust toolchain (nightly 2022-09-07)
• MinGW-w64 (10.0.0+)
• wasm-strip from WABT

Prerequisites on macOS

brew install rustup mingw-w64 wabt

Prerequisites on Ubuntu

curl -sSf https://sh.rustup.rs | sh

apt install mingw-w64 wabt

Release Builds

rustup target add wasm32-wasi
rustup target add wasm32-unknown-unknown
rustup target add aarch64-apple-darwin
rustup target add x86_64-apple-darwin
rustup target add aarch64-pc-windows-msvc
rustup target add x86_64-pc-windows-gnu
rustup target add aarch64-unknown-linux-musl
rustup target add x86_64-unknown-linux-musl
make clean release

Benchmarks

You can see results of gas-spent measurements here