Minting your first Asset¶

When you use Iroha in your application you will definitely face the need to mint an asset. Use this tutorial to master Iroha Special Instructions in general and MintAsset in particular.

Prerequisites¶

Rust
Text Editor or IDE
Existing Rust project //TODO: create some sandbox project

Steps¶

1. Add dependency on Iroha crate¶

Inside path_to_your_project/Cargo.toml add a new dependency:

iroha = "2.0.0"

2. Find a place where you need to mint an asset¶

Usually any business operation will have a need to mint an asset:

Uploading of digital documents
Withdrawl and initial supply of crypto currencies
Etc.

Look at your project and find a good place to put it, which will encapsulate Iroha related logic inside and may be easily modified if needed in future.

3. Use Iroha CLI Client to prepare Iroha Peer¶

Iroha Special Instructions executed on behalf of an authority - Account.

If you already has an account to store assets on - feel free to skip these step. If not - you will need to receive Account’s Key Pair with permissions to Register an Account.

TL;DR - after configuration of Iroha CLI run this command:

./iroha_client_cli account register --domain="my_domain" --name="my_account" --key="{account_public_key}"

4. Construct Iroha Special Instruction¶

Now we can write some real code, let’s imagine that you need to mint 200 amount of crypto currency “xor”:

let mint_asset = isi::Mint {
    object: 200,
    destination_id: AssetId {
        definition_id: "xor#soramitsu",
        account_id: "my_account@my_domain",
    },
};

And let’s see what it consist of:

isi module contains basic Iroha special instructions functionality
Mint structure is a declaration - “Iroha - Mint this object to the following destination”
object in our case is an amount of “xor” to mint. In other cases it can be bytes of digital document or other data.
destination_id in our case is an asset’s identification which consist of a asset’s definition identification and account’s identification cross product.

This functionality also available via Iroha CLI Client but we did it via Rust code on purpose.

5. Submit Iroha Special Instruction¶

iroha_client
  .submit(mint_asset.into())
  .await
  .expect("Failed to mint an asset.");

iroha_client provides functionality to submit iroha special instructions and it will be automatically “pack” them into transaction signed on behalf of the client. As a result of this operation you will receive transaction acceptance status - if transaction was accepted by the peer (signature was valid and payload is legal set of iroha special instructions) then it will be Result::Ok(()), if some problems arrive - it will be Result::Err(String) with textual error message.

Conclusion¶

It is necessary to be aware of Iroha domain model and set of out-of-the-box Iroha Special Instructions and Queries to develop custom projects based on it. But once you understand this model, it provides very simple and clean approach to declaratively define desired steps and send them for execution.