Quick Start Guide: Developing Nucleus on Verisense

Welcome to Verisense! This guide will help you quickly get started with developing your first Nucleus using Rust. By the end, you’ll have a simple deployed Nucleus and be able to interact with it.

1. Set Up Your Rust Environment

First, install Rust and configure it for WebAssembly (Wasm) compilation:

Install Rust:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Add the WebAssembly target:

rustup target add wasm32-unknown-unknown

2. Create and Compile a Rust Project

Create a new Rust library:

cargo new --lib hello-avs
cd hello-avs

Update Cargo.toml

[package]
name = "hello-avs"
version = "0.1.0"
edition = "2021"

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

[dependencies]
vrs-core-sdk = { version = "0.0.2" }
parity-scale-codec = { version = "3.6", features = ["derive"] }

Write your first Nucleus code:

#![allow(unused)]
fn main() {
use parity_scale_codec::{Decode, Encode};
use vrs_core_sdk::{get, post, storage};

#[derive(Debug, Decode, Encode)]
pub struct User {
    pub id: u64,
    pub name: String,
}

#[post]
pub fn add_user(user: User) -> Result<u64, String> {
    let max_id_key = [&b"user:"[..], &u64::MAX.to_be_bytes()[..]].concat();
    let max_id = match storage::search(&max_id_key, storage::Direction::Reverse)
        .map_err(|e| e.to_string())?
    {
        Some((id, _)) => u64::from_be_bytes(id[5..].try_into().unwrap()) + 1,
        None => 1u64,
    };
    let key = [&b"user:"[..], &max_id.to_be_bytes()[..]].concat();
    storage::put(&key, user.encode()).map_err(|e| e.to_string())?;
    Ok(max_id)
}

#[get]
pub fn get_user(id: u64) -> Result<Option<User>, String> {
    let key = [&b"user:"[..], &id.to_be_bytes()[..]].concat();
    let r = storage::get(&key).map_err(|e| e.to_string())?;
    let user = r.map(|d| User::decode(&mut &d[..]).unwrap());
    Ok(user)
}
}

Build the project for WebAssembly:

cargo build --release --target wasm32-unknown-unknown

3. Install Command-Line Tools and Get Free Gas

Install the Verisense CLI:

cargo install --git https://github.com/verisense-network/vrs-cli.git

Generate an account:

vrx account generate --save

This command will generate an account and save the private key to ~/.vrx/default-key. Example output:

Phrase: exercise pipe nerve daring census inflict cousin exhaust valve legend ancient gather
Seed: 0x35929b4e23d26c5ba94d22d32222128e56f5a7dce35f9b36b467ac2be2b4d29b
Public key: 0x9cdaa67b771a2ae3b5e93b3a5463fc00e6811ed4f2bd31a745aa32f29541150d
Account Id: kGj5epfCkuae7DJpezu5Qx6mp96gHmLv2kDPHHTdJaEVNptRt

Request free gas:

Chat with the Verisense Faucet Bot and provide your account ID to request free $VRS.

4. Create and Deploy a Nucleus

Create a Nucleus:

vrx nucleus --devnet create --name hello_avs --capacity 1

Example output:

Nucleus created.
  id: kGieDqL1fX8J7n1vRbXri7DVphwnZJpkDcoMoQZWo9XkTt1Sv
  name: hello_avs
  capacity: 1

Deploy the compiled Wasm:

vrx install --wasm target/wasm32-unknown-unknown/release/hello_avs.wasm --id kGieDqL1fX8J7n1vRbXri7DVphwnZJpkDcoMoQZWo9XkTt1Sv

If successful, you will see output like this:

Digest: 0xff878e546806da8b13f02765ea84f616963abcfdcac196ba3ea9f3f5d94b661e
Peer ID: 12D3KooWCz46orfkSfaahJqkph1bQqXU9t7ct98YQKTaDepNE6du
Transaction submitted: "0x0bc7d23b900a880e5274582755fc1a6c17df9453b0aa43f4cc382efc0bf1ec39"

5. Test Your Nucleus

Call add_user:

curl https://alpha-devnet.verisense.network -H 'Content-Type: application/json' -XPOST -d '{"jsonrpc":"2.0", "id":"whatever", "method":"nucleus_post", "params": ["kGieDqL1fX8J7n1vRbXri7DVphwnZJpkDcoMoQZWo9XkTt1Sv", "add_user", "000000000000000014416c696365"]}'

The networking component follows the standard JSON-RPC specification, and all post and get methods share a same endpoint separately. In the add_user case, the method is nucleus_post and so all other post methods.

The first parameter is the nucleus_id we just deployed, the second indicates the function name in the source code which is add_user. While the third is an parity-scale-encoded bytes whose value is: User {0, "Alice"}. You can find different implementations for various programming languages.

Call get_user:

Calling get_user is similar, we just need to change the method and parameter:

curl https://alpha-devnet.verisense.network -H 'Content-Type: application/json' -XPOST -d '{"jsonrpc":"2.0", "id":"whatever", "method":"nucleus_get", "params": ["kGieDqL1fX8J7n1vRbXri7DVphwnZJpkDcoMoQZWo9XkTt1Sv", "get_user", "0100000000000000"]}'

Conclusion

Congratulations! You’ve created, deployed, and interacted with your first Nucleus on Verisense. You can now expand your AVS functionality and explore advanced features of the platform.

For more information, check the Verisense documentation.

What's next

For more advanced topics, see:

Verisense Docs