TZIP-12 Token Standard
Implemented by Stove Labs, proposed by the TQTezos.
TZIP-12 is a next generation token standard aiming to standardize integration & token data exchange between smart contracts and clients. It supports multiple token types, such as Fungible, Non-Fungible, Non-Transferrable or others.
Data Structure
(* token_id is a nat, following the TZIP-12 spec *)
type token_id is nat;
type token_owner is address;
(* token_balance is either 0 or positive, therefore it's a nat *)
type token_balance is nat;
(*
token_lookup_id is always a unique combination of a token_id and a token_owner,
representing a key in the big_map of token_balances
*)
type token_lookup_id is record
token_id : token_id;
token_owner : token_owner;
end;
type token_balances is big_map(token_lookup_id, token_balance);
(*
Total supply is persisted separately rather than computed at each request
in order to optimise gas costs.
*)
type total_token_supply_count is nat;
type total_token_supply is big_map(token_id, total_token_supply_count);
type storage is record
token_balances : token_balances;
(* See https://www.wordhippo.com/what-is/the-plural-of/supply.html *)
total_token_supply : total_token_supply;
end;
Available Entrypoints
type transfer is record
token_id : token_id;
amount : token_balance;
from_ : token_owner;
to_ : token_owner;
end;
type transfer_param is list(transfer);
type action is
| Transfer of transfer_param
| Balance_of of balance_of_param
| Total_supply of total_token_supply_param
(* Default function that represents our contract, it's sole purpose here is the entrypoint routing *)
function main (const action : action; var storage : storage) : (list(operation) * storage)
is (case action of
(*
Unwrap the `Transfer(...)` parameters and invoke the transfer function.
The return value of `transfer(...)` is then returned as a result of `main(...)` as well.
*)
| Transfer(transfer_param) -> transfer(transfer_param, storage)
| Balance_of(balance_of_param) -> balance_of(balance_of_param, storage)
| Total_supply(total_token_supply_param) -> total_token_supply(total_token_supply_param, storage)
end)
Token deployment
⚠️ Please see the full README for comprehensive usage instructions.
Set up the development environment
git clone https://github.com/stove-labs/tzip-12
cd tzip-12
npm i
Configure the initial token storage state
// migrations/tzip_12.js
const tokenBalance = 10;
const tokenId = 0;
/**
* Generate lookup IDs for both alice & bob with tokenId = 0
*/
const tokenLookupIdAlice = getTokenLookupId(tokenId, alice.pkh);
/**
* Initialize the storage with Alice owning a certain token balance.
*/
const initialStorage = {
token_balances: new MichelsonMap(),
total_token_supply: new MichelsonMap()
};
initialStorage.token_balances.set(tokenLookupIdAlice, tokenBalance);
initialStorage.total_token_supply.set(
tokenId,
calculateTotalTokenSupply(initialStorage)
);
Migrate the contract
// Start a private sandbox network in Docker 🐳
npm run start-sandbox -- carthage
// Migrate the token contract
npm run migrate
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