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Build contracts in Rust

Prerequisites​

  • Rust stable + wasm32-unknown-unknown target
  • cargo-generate or clone cosmwasm-template
  • Docker (for cosmwasm/optimizer)
rustup target add wasm32-unknown-unknown
cargo install cargo-generate
cargo generate --git https://github.com/CosmWasm/cosmwasm-template.git --name my_contract

Project layout​

my_contract/
  src/
    contract.rs   # instantiate, execute, query
    msg.rs        # JSON message types
    state.rs      # storage
  Cargo.toml      # cosmwasm-std dependency

Minimal handlers​

use cosmwasm_std::{Deps, DepsMut, Env, MessageInfo, Response, StdResult};

pub fn instantiate(_deps: DepsMut, _env: Env, _info: MessageInfo, _msg: InstantiateMsg) -> StdResult<Response> {
    Ok(Response::new().add_attribute("action", "instantiate"))
}

pub fn execute(_deps: DepsMut, _env: Env, _info: MessageInfo, _msg: ExecuteMsg) -> StdResult<Response> {
    Ok(Response::new().add_attribute("action", "execute"))
}

pub fn query(_deps: Deps, _env: Env, _msg: QueryMsg) -> StdResult<Binary> {
    todo!()
}

Test and build​

cargo test
docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="$(basename "$(pwd)")_cache",target=/target \
  cosmwasm/optimizer:0.16.0
# artifacts/my_contract.wasm

Next​

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