Contract Guide Skill

This skill provides expert guidance for writing smart contracts on Initia. It helps identify the correct libraries, naming conventions, and deployment patterns for Move, Wasm, and EVM.

MoveVM

Project Structure

A typical MoveVM project on Initia has the following structure:

.
├── Move.toml
└── sources
    └── *.move

• Move.toml: The manifest file that defines the project’s metadata, dependencies, and addresses.
• sources/: The directory containing the Move source code files.

Key Libraries and Dependencies

• InitiaStdlib: The standard library for Initia Move modules. It is typically included as a dependency in Move.toml:

  [dependencies]
  InitiaStdlib = { git = "https://github.com/initia-labs/movevm.git", subdir = "precompile/modules/initia_stdlib", rev = "main" }
  

Naming Conventions

• Modules and Functions: snake_case (e.g., module my_module, fun my_function).

Example: Oracle Integration

Here is an example of a Move module that interacts with an oracle:

module example::oracle_example {
    use std::string::String;
    use initia_std::oracle::get_price;

    #[view]
    public fun get_price_example(pair_id: String): (u256, u64, u64) {
        let (price, timestamp, decimals) = get_price(pair_id);
        (price, timestamp, decimals)
    }

    #[test]
    public fun test_get_price_example(): (u256, u64, u64) {
        let btc_usd_pair_id = string::utf8(b"BITCOIN/USD");
        let (price, timestamp, decimals) = get_price_example(btc_usd_pair_id);
        (price, timestamp, decimals)
    }
}

WasmVM (CosmWasm)

Project Structure

A typical WasmVM project on Initia follows the standard CosmWasm project structure:

.
├── Cargo.toml
└── src
    ├── lib.rs
    ├── contract.rs
    ├── msg.rs
    ├── state.rs
    └── error.rs

Key Libraries and Dependencies

• cosmwasm-std: The standard library for CosmWasm contracts.
• cw-storage-plus: A library for managing contract storage.
• slinky_wasm: A specific library for interacting with Initia’s oracle.

Example Cargo.toml dependencies:

[dependencies]
cosmwasm-schema = "2.0.1"
cosmwasm-std = { version = "2.0.1", features = ["cosmwasm_1_3"] }
cw-storage-plus = "2.0.0"
cw2 = "2.0.0"
schemars = "0.8.16"
serde = { version = "1.0.197", default-features = false, features = ["derive"] }
thiserror = { version = "1.0.58" }
slinky_wasm = { path = "packages/slinky_wasm" }

Coding Patterns

• Entry Points: Use the standard #[entry_point] macro for instantiate, execute, and query functions.
• Oracle Integration: Use the slinky_wasm library to query the oracle. Queries are made using QueryRequest::Wasm(WasmQuery::Smart { ... }).

Example: Oracle Query

pub mod query {
    use cosmwasm_std::{QueryRequest, WasmQuery};
    use slinky_wasm::oracle::GetAllCurrencyPairsResponse;

    // ...

    pub fn example_get_price(deps: Deps) -> StdResult<GetPriceResponse> {
        let state = STATE.load(deps.storage)?;
        let slinky_addr = state.slinky;

        let base_asset = "BTC";
        let quote_asset = "USD";

        deps.querier.query(&QueryRequest::Wasm(WasmQuery::Smart {
            contract_addr: slinky_addr.to_string(),
            msg: to_json_binary(&slinky_wasm::oracle::QueryMsg::GetPrice {
                base: base_asset.to_string(),
                quote: quote_asset.to_string(),
            })?,
        }))
    }
}

EVM (Solidity)

Project Structure

A typical EVM project on Initia uses the Foundry toolchain:

.
├── foundry.toml
├── src
│   └── *.sol
├── lib
└── script

Key Libraries and Dependencies

• initia-evm-contracts: The key library for Initia EVM development. It is usually included as a git submodule in the lib directory.

Coding Patterns

• Oracle Integration: Use the ISlinky interface from initia-evm-contracts to interact with the oracle.

Naming Conventions

• Functions: snake_case
• Variables: camelCase

Example: Oracle Integration

pragma solidity ^0.8.24;

import "initia-evm-contracts/src/interfaces/ISlinky.sol";

contract Oracle {

    ISlinky immutable public slinky;

    constructor (address _slinky) {
        slinky = ISlinky(_slinky);
    }

    function oracle_get_price() external {
        string memory base = "BTC";
        string memory quote = "USD";
        price = slinky.get_price(base, quote);
    }
}