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Pallet-Assets Chain Extension

API​

This chain extension allows contracts to call pallet-assets functions.
It includes extrinsics:

fn mint()
fn burn()
fn transfer()
fn approve_transfer()
fn transfer_approved()

And these queries:

fn balance_of()
fn total_supply()
fn allowance()
fn metadata_name()
fn metadata_symbol()
fn metadata_decimals()
fn minimum_balance()

Some extrinsics are NOT part of the chain extension because they have no or limited usage for smart contracts.

fn create()
fn cancel_approval()
fn set_metadata()
fn transfer_ownership()
fn clear_metadata()
fn start_destroy()
fn destroy_accounts()
fn destroy_approvals()
fn finish_destroy()
fn freeze()
fn freeze_asset()
fn refund()
fn set_team()
fn thaw()
fn touch()
fn transfer_keep_alive()

Only call on behalf of the contract is implemented​

The Origin of the call is the contract address calling the chain-extension. The caller is this case is the address that calls the contract.

Usage in your contract​

Please check the Chain Extension library repo and use assets-extension crate: LINK

note

Your contract should be in ink! 4.3 or above

  1. add assets_extension in your Cargo.toml and to the std features
assets_extension = {  git = "https://github.com/AstarNetwork/chain-extension-contracts", default-features = false }

[features]
default = ["std"]
std = [
    "ink/std",
    "scale/std",
    "scale-info/std",
    "assets_extension/std",
]
  1. Add use statement in your contract module
use assets_extension::{AssetsError, AssetsExtension as _AssetsExtension};

type AssetsExtension = _AssetsExtension<DefaultEnvironment>;
  1. Use struct functions directly in your contract
AssetsExtension::mint(asset_id, beneficiary, amount)?;