canpack

canpack  

Package multiple libraries into one ICP canister.

canpack is a code generation tool which makes it easier to use Rust crates in different languages (such as Motoko) on the Internet Computer.

Note

This project is early in development; unannounced breaking changes may occur at any point.

Quick Start

TODO: Gitpod URL

Manual Setup

Ensure that the following software is installed on your system:

• dfx (latest version)
• Rust (stable or nightly)
• Node.js >= 16.x

To create a new Motoko project, run dfx new my_project, selecting "Motoko" for the backend and "No frontend canister" for the frontend. Once complete, run cd my_project and open in your editor of choice.

Add a new file named canpack.json (in the same directory as dfx.json).

Define a Rust canister named my_project_backend_rust in your canpack.json file:

{
    "canisters": {
        "my_project_backend_rust": {
            "type": "rust",
            "parts": [{
                "package": "canpack-example-hello",
                "version": "^0.0.1"
            }]
        }
    }
}

Next, run the following command in this directory to generate all necessary files:

npx canpack

In your dfx.json file, configure the "dependencies" for the Motoko canister:

{
    "canisters": {
        "my_project_backend": {
            "dependencies": ["my_project_backend_rust"],
            "main": "src/my_project_backend/main.mo",
            "type": "motoko"
        }
    },
}

Now you can call Rust functions from Motoko using a canister import:

import Rust "canister:my_project_backend_rust";

actor {
    public func hello(name: Text) : async Text {
        await Rust.canpack_example_hello(name)
    } 
}

Run the following commands to build and deploy the dfx project on your local machine:

dfx start --background
dfx deploy

Rust Crates

Add Canpack support to any IC Wasm-compatible Rust crate by exporting a top-level canpack! macro.

For example (in your lib.rs file):

pub fn hello(name: String) -> String {
    format!("Hello, {name}!")
}

#[macro_export]
macro_rules! canpack {
    () => {
        #[ic_cdk::query]
        #[candid::candid_method(query)]
        fn canpack_example_hello(name: String) -> String {
            $crate::hello(name)
        }
    };
}