KIP-7 is an FT (Fungible Token) contract standard defined by Klaytn. KAS provides the KIP-7 API for conveniently creating and managing KIP-7 tokens. The main features of KIP-7 API are KIP-7 contract deployment and minting/burning/sending tokens.

In this tutorial, we will walk you through how to deploy KIP-7 contracts, as well as how to mint and transfer KIP-7 tokens, using the KIP-7 API. For more details, please refer to KAS KIP-7 API Reference.

Deploying KIP-7 Contract

The KIP-7 API deploys and manages FT contracts that follow the KIP-7 standard.

API Request

You can deploy a KIP-7 contract by executing the following curl command.

curl --location --request POST "https://kip7-api.klaytnapi.com/v2/contract" \
  --header "x-chain-id: {chain-id}" \
  -u {access-key-id}:{secret-access-key} \
  --data-raw '{
  "alias": "my-first-kip7",
  "name": "My First KIP-7",
  "symbol": "MFK",
  "decimals": 8,
  "initialSupply": "0x100000000"
  }'

const result = await caver.kas.kip7.deploy(
  "My First KIP-7",
  "MFK",
  8,
  "0x100000000",
  "my-first-kip7"
);

String alias = "my-first-kip7";
String name = "My First KIP-7";
String symbol = "MFK";
int decimals = 8;
String initialSupply = "0x100000000";

Kip7TransactionStatusResponse response = caver.kas.kip7.deploy(name, symbol, decimals, initialSupply, alias);

We will break down curl command in parts. You can call Deploy Contract API with the endpoint POST /v2/contract. Since KIP-7 API is being serviced by https://kip7-api.klaytnapi.com, set the URL for curl as https://kip7-api.klaytnapi.com/v2/contract, with the request type as POST (—-request POST).

Contract Deploy API accepts the POST request and requires the following JSON data.

{
  "alias": "my-first-kip7",
  "name": "My First KIP-7",
  "symbol": "MFK",
  "decimals": 8,
  "initialSupply": "0x100000000"
}

Here is a brief description of each field:

• Alias ( alias ): Nickname of the contract. It can be used in place of the contract address in different APIs. Allowed characters are lowercase letters, numbers, and hyphens; and the first letter must be a lowercase alphabet.
• Name ( name ): Name given to the contract. Used as name in accordance with the KIP-7 standard.
• Symbol ( symbol ): Symbol of the contract. Used as symbol in accordance with the KIP-7 standard. It usually consists of 3-4 uppercase letters, but there is no restriction.
• Decimals ( decimals ): Token decimals. Used as decimals in accordance with the KIP-7 standard. 18 decimals is the standard practice.
• InitialSupply( initialSupply ): The inital token supply of the contract. Used as totalSupply in accordance with the KIP-7 standard.
• Required Headers

  All KIP-7 APIs require x-chain-id header. Accepted values are 1001 (Baobab) and 8217 (Cypress).

• Authentication

  For all APIs provided by KAS, credentials must be provided: the access-key-id and secret-access-key. More on generating and obtaining credentials, please refer to Link.

API Response

Executing the curl command for token deployment will return the following result:

{
  "status": "Submitted",
  "transactionHash": "0xde30017fa4474274bd8e0f8bf4eea799d6873d1f2e24f5d7afe97400b24acf4c"
}

 {
  status: 'Submitted',
  transactionHash: '0xe5bf5cbd8d9f13e31af8e1cac1ff7749f649779a1e0eb62579012b38ff7737c3'
}

 class Kip7TransactionStatusResponse {
    status: Submitted
    transactionHash: 0x55bcaa84037ce8c25c1f3560868d0d13af01fa13faeabc4547e712f6be3cc350
}

You can use transactionHash returned in the response to execute RPC functions such as klay_getTransactionReceipt.

Getting KIP-7 Contract List

API Request

KIP-7 API's Get Contract List API(GET /v2/contract) can be used for retrieving a list of deployed contracts. You can do this by running the curl command:

curl --location --request GET 'https://kip7-api.klaytnapi.com/v2/contract' \
  --header "x-chain-id: {chain-id}" \
  -u {access-key-id}:{secret-access-key}

const queryOptions = {
  size: 1,
  status: caver.kas.kip7.queryOptions.status.DEPLOYED,
};
const result = await caver.kas.kip7.getContractList(queryOptions);

KIP7QueryOptions options = new KIP7QueryOptions();
options.setSize(1);
options.setStatus(KIP7QueryOptions.STATUS_TYPE.DEPLOYED);

Kip7ContractListResponse response = caver.kas.kip7.getContractList(options);

API Response

If your contract has been successfully deployed, you will get the following response.

{
  "items": [
    {
      "address": "0x33779fc606de8b1c1095dc3760be4c4f8b2a1ad3",
      "alias": "my-first-kip7",
      "decimals": 8,
      "name": "My First KIP-7",
      "status": "deployed",
      "symbol": "MFK",
      "totalSupply": "0x100000000"
    }
  ],
  "cursor": ""
}

{
  items: [
    {
      address: '0x05a86c8e60aefb9ce975fe26511f72da86ab2a7a',
      alias: 'my-first-kip7',
      decimals: 8,
      name: 'My First KIP-7',
      status: 'deployed',
      symbol: 'MFK',
      totalSupply: '0x100000000'
    }
  ],
  cursor:  'eyJjcmVhdGVkX2F0IjoxNjIxODE4NTQwLCJpZCI6ImNvbnRyYWN0IzEwMDEjMTczZGI2OWMtZjFiOC00ZGQ1LTlhYzItZWQ4YTBiYWRhYjI5Iiwic19pZCI6Imphc21pbmUtcWNvYnNiNnM2d2oifQ=='
}

class Kip7ContractListResponse {
    items: [class Kip7ContractListResponseItem {
        address: 0x7b635e298b345022fbe8c53d2646ed690e0f1cb2
        alias: my-first-kip7
        decimals: 8
        name: My First KIP-7
        status: deployed
        symbol: MFK
        totalSupply: 0x100000000
    }]
    cursor: eyJjcmVhdGVkX2F0IjoxNjI0OTQ2Njc5LCJpZCI6ImNvbnRyYWN0IzEwMDEjZDVjMzQ2ZjUtYmI4MC00ZjQ1LTkwOTMtNTdlMjUyMDVjZGM4Iiwic19pZCI6ImtrLTE2MjQ5NDY2NzkzMzEifQ==
}

Minting KIP-7 Tokens

If you successfully deployed your contract, you can start minting tokens now. The API for minting tokens is POST /v2/contract/{contract-address-or-alias}/mint. The path parameter {contract-address-or-alias} is the alias or the address of the contract that will be minting the tokens. You can use the alias submitted for minting tokens, or the address that you found on the Get Contract List API after deploying the contract.

API Request

Below is the curl command for calling Mint Token API using the alias my-first-kip7 from the previous example.

curl --location --request POST 'https://kip7-api.klaytnapi.com/v2/contract/my-first-kip7/mint' \
  --header "x-chain-id: {chain-id}" \
  -u {access-key-id}:{secret-access-key} \
 --data-raw '{
   "to": "0x72b03ca464609c82be1d490ecfce004e2d3c4cfc",
   "amount": "0x100"
}'

const result = await caver.kas.kip7.mint(
  "my-first-kip7",
  "0x72b03ca464609c82be1d490ecfce004e2d3c4cfc",
  "0x100"
);

String alias = "my-first-kip7";
String to = "0x72b03ca464609c82be1d490ecfce004e2d3c4cfc";
String amount = "0x100";

Kip7TransactionStatusResponse response = caver.kas.kip7.mint(alias, to, amount);

The required header and authentication data are the same as those for contract deployment. You can enter data such as location, or send request in the same way as for Mint Token API (POST /v2/contract/{contract-address-or-alias}/mint).

Token Mint API requires the following JSON data:

{
  "to": "0x72b03ca464609c82be1d490ecfce004e2d3c4cfc",
  "amount": "0x100"
}

• Recipient ( to ): Klaytn account address of the token recipient. Mint Token API will mint a new token in a designated address.
• Amount ( amount ): The amount of tokens to be created. It is hexadecimal and uses values that include decimals . The above tutorial creates 0.00000256(0x100 / 10 ^ 8) MFK tokens.

API Response

Executing the curl command for creating tokens, you will get the following response.

{
  "transactionHash": "0x8fa73465785c5aedc7df3123ed2670f37f3cd42f63d32c53aba37c8fe1afc078",
  "status": "Submitted"
}

{
  status: 'Submitted',
  transactionHash: '0xe4db23b626f98e592156b4e69761cfecff414839fbcec0b6b73080d8a6b0a3e9'
}

class Kip7TransactionStatusResponse {
    status: Submitted
    transactionHash: 0x3198aa4826852e8897b2af78fe0b1974071c5110ec32c379d559bb8108d044c1
}

You will see a response that looks like the example above, which is the same as the one for contract deployment.

Getting Token Balance

API Request

To check if your token has been minted correctly, use Get Token Balance API (GET /v2/contract/{contract-address-or-alias}/account/{owner}/balance) and check the balance for the owner's address. You can use the following curl command to check the balance of the account 0x72b03ca464609c82be1d490ecfce004e2d3c4cfc of the my-first-kip7 contract.

curl --location --request GET 'https://kip7-api.klaytnapi.com/v2/contract/my-first-kip7/account/0x72b03ca464609c82be1d490ecfce004e2d3c4cfc/balance' \
  --header "x-chain-id: {chain-id}" \
  -u {access-key-id}:{secret-access-key}

const result = await caver.kas.kip7.balance(
  "my-first-kip7",
  "0x72b03ca464609c82be1d490ecfce004e2d3c4cfc"
);

String alias = "my-first-kip7";
String account = "0x72b03ca464609c82be1d490ecfce004e2d3c4cfc";
Kip7TokenBalanceResponse response = caver.kas.kip7.balance(alias, account);

API Response

If the token has been minted successfully, you will receive the following response.

{
  "balance": "0x100",
  "decimals": 8
}

{ balance: '0x100', decimals: 8 }

class Kip7TokenBalanceResponse {
    balance: 0x100
    decimals: 8
}

Transferring KIP-7 Tokens

KIP-7 Token Transfer API is POST /v2/contract/{contract-address-or-alias}/transfer. {contract-address-or-alias} refers to the contract that you wish to use.

Create an account on KAS Wallet Account Pool(https://console.klaytnapi.com/en/service/wallet/accounts/list) before using KAS KIP-7 Token Transfer API. The account address used in this tutorial (0x72b03ca464609c82be1d490ecfce004e2d3c4cfc) is an account registered in advance.

API Request

Below is the curl command for sending one token of the my-first-kip7 contract owned by 0x72b03ca464609c82be1d490ecfce004e2d3c4cfc to 0x4d3224314b704be8887551e8c9b9bbb9aa5c48b3:

curl --location --request POST 'https://kip7-api.klaytnapi.com/v2/contract/my-first-kip7/transfer' \
  --header "x-chain-id: {chain-id}" \
  -u {access-key-id}:{secret-access-key} \
 --data-raw '{
   "from": "0x72b03ca464609c82be1d490ecfce004e2d3c4cfc",
   "to": "0x4d3224314b704be8887551e8c9b9bbb9aa5c48b3",
   "amount": "0x1"
 }'

const result = await caver.kas.kip7.transfer(
  "my-first-kip7",
  "0x72b03ca464609c82be1d490ecfce004e2d3c4cfc",
  "0x4d3224314b704be8887551e8c9b9bbb9aa5c48b3",
  "0x1"
);

String alias = "my-first-kip7";
String owner = "0x72b03ca464609c82be1d490ecfce004e2d3c4cfc";
String spender = "0x4d3224314b704be8887551e8c9b9bbb9aa5c48b3";
String amount = "0x1";

Kip7TransactionStatusResponse response = caver.kas.kip7.transfer(alias, owner, spender, amount);

The JSON data required for trasferring tokens are as follows:

• From ( from ): The address of the token owner
• To ( to ): The address of the token recipient. Keep in mind that due to the nature of blockchain, once a token is transferred, it is irreversible.
• Amount ( amount ): Amount of tokens to send. In hexadecimal without decimals .

If from is inaccurate or the balance is insufficient, the transfer request will fail.

API Response

Executing the Token Transfer API will return the following response:

{
  "transactionHash": "0xf55b6bda2b0b610b461f0a8533001d38e4fad95a77eb4e2a60d38c14fdf0c997",
  "status": "Submitted"
}

{
  status: 'Submitted',
  transactionHash: '0x736dd99fc06dbc237d55eddf204b053fdc35b07faf30dcd1bfa504c7cb651192'
}

class Kip7TransactionStatusResponse {
    status: Submitted
    transactionHash: 0xcc5a4bd89cf64d6dc72bcc00b7743f524bfc9d78c6d37ba510c993d75f740c48
}

Getting Token Balance

API Request

To check if your token has been transferred successfully, use Get Token Balance API (GET /v2/contract/{contract-address-or-alias}/account/{owner}/balance). You should see that your token balance is updated.

curl --location --request GET 'https://kip7-api.klaytnapi.com/v2/contract/my-first-kip7/account/0x4d3224314b704be8887551e8c9b9bbb9aa5c48b3/balance' \
  --header "x-chain-id: {chain-id}" \
  -u {access-key-id}:{secret-access-key}

const result = await caver.kas.kip7.balance(
  "my-first-kip7",
  "0x4d3224314b704be8887551e8c9b9bbb9aa5c48b3"
);

String alias = "my-first-kip7";
String account = "0x4d3224314b704be8887551e8c9b9bbb9aa5c48b3";

Kip7TokenBalanceResponse response = caver.kas.kip7.balance(alias, account);

API Response

If your token is transferred successfully, the balance will be updated as below:

{
  "balance": "0x1",
  "decimals": 8
}

{ balance: '0x1', decimals: 8 }

class Kip7TokenBalanceResponse {
    balance: 0x1
    decimals: 8
}