Creating Zink Project

For creating a zink project, we need to install the zink toolchain zinkup from crates.io first, the package manager elko will be installed along with other tools:

cargo install zinkup
elko -h

Now, let’s create a zink project:

elko new my-awesome-contract
Created zink project `my-awesome-contract`

the Zink projects are based on the cargo projects, you can install dependencies you need with cargo, the basic Cargo.toml will be like:

# ...

[lib]
crate-type = [ "cdylib" ]

[dependencies]
zink = "0.1.0"

# ...

open my-awesome-contract/src/lib.rs

//! my-awesome-project
#![no_std]

// For the panic handler.
#[cfg(not(test))]
extern crate zink;

/// Adds two numbers together.
#[no_mangle]
pub extern "C" fn addition(x: u64, y: u64) -> u64 {
    x + y
}

you’ll see a standard WASM library in rust:

  1. #![no_std] means we don’t need the std library in this project.
  2. extern crate zink is for importing the panic handler from library zink for this project.
  3. #[no_mangle] is for exporting function addition to WASM, and this will be one the methods of your contracts.