> For the complete documentation index, see [llms.txt](https://docs.kubchain.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.kubchain.com/quickstart/launching-a-token-on-kub/kap-token-interfaces/kap-20.md). # KAP-20 The following standard outlines a smart contract interface and logic for fungible tokens on KUB that supports an `adminTransfer` function designed to create transactions on behalf of token holders if they have been a victim of a fraudulent transaction. It is proposed by deriving the ERC-20 standard of Ethereum with additional functions related to `adminTransfer`. ## Token Interface ### IAdminProjectRouter #### isSuperAdmin Check whether `_addr` is the Super Admin role in `_project`. ```solidity function isSuperAdmin(address _addr, string calldata _project) external view returns (bool) ``` #### isAdmin Check whether `_addr` is the Admin role in `_project`. ```solidity function isAdmin(address _addr, string calldata _project) external view returns (bool) ``` ### IKYCBitkubChain #### kycsLevel Returns the KYC Level of `_addr` ```solidity function kycsLevel(address _addr) external view returns (uint256) ``` ### IKAP20 #### totalSupply Returns the total token supply. ```solidity function totalSupply() external view returns (uint256) ``` #### decimals Returns the number of decimals the token uses - e.g. `8`, means to divide the token amount by `100000000` to get its user representation. ```solidity function decimals() external view returns (uint8) ``` {% hint style="info" %} NOTE: This method is optional in ERC-20. In KAP-20, this is a required method. {% endhint %} #### symbol Returns the symbol of the token. E.g. "HIX". ```solidity function symbol() external view returns (string memory) ``` {% hint style="info" %} NOTE: This method is optional in ERC-20. In KAP-20, this is a required method. {% endhint %} #### name Returns the name of the token - e.g.`"MyToken"`. ```solidity function name() external view returns (string memory) ``` {% hint style="info" %} NOTE: This method is optional in ERC-20. In KAP-20, this is a required method. {% endhint %} #### balanceOf Returns the account balance of another account with address `account`. ```solidity function balanceOf(address account) external view returns (uint256) ``` {% hint style="info" %} NOTE: This method is optional in ERC-20. In KAP-20, this is a required method. {% endhint %} #### transfer Transfers `amount` amount of tokens to address `recipient`, and MUST fire the `Transfer` event. The function SHOULD `throw` if the message caller's account balance does not have enough tokens to spend. ```solidity function transfer(address recipient, uint256 amount) external returns (bool) ``` {% hint style="info" %} NOTE: Transfers of 0 values MUST be treated as normal transfers and fire the `Transfer` event. {% endhint %} #### allowance Returns the amount which `spender` is still allowed to withdraw from `owner`. ```solidity function allowance(address owner, address spender) external view returns (uint256) ``` #### approve Allows `spender` to withdraw from your account multiple times, up to the `amount` amount. If this function is called again, it overwrites the current allowance with `amount`. ```solidity function approve(address spender, uint256 amount) external returns (bool) ``` {% hint style="info" %} NOTE: To prevent attack vectors, clients SHOULD make sure to create user interfaces in such a way that they set the allowance first to 0 before setting it to another value for the same spender. THOUGH The contract itself shouldn't enforce it, to allow backwards compatibility with contracts deployed before {% endhint %} #### adminApprove Allows `spender` to withdraw from `owner` account multiple times, up to the `amount` amount. If this function is called again it overwrites the current allowance with `amount`. This method works similarly to the `approve` method. ```solidity function adminApprove(address owner, address spender, uint256 amount) external returns (bool) ``` {% hint style="info" %} NOTE: This function can only be called by the Admin and Super Admin. This function is designed to create transactions automatically on behalf of token holders if they have been a victim of a fraudulent transaction. {% endhint %} #### transferFrom Transfers `amount` amount of tokens from address `sender` to address `recipient`, and MUST fire the Transfer event. The `transferFrom` method is used for a withdraw workflow, allowing contracts to transfer tokens on your behalf. This can be used for example, to allow a contract to transfer tokens on your behalf and/or to charge fees in sub-currencies. The function SHOULD `throw` unless the `sender` account has deliberately authorized the sender of the message via some mechanism. ```solidity function transferFrom(address sender, address recipient, uint256 amount) external returns (bool) ``` {% hint style="info" %} NOTE: Transfers of 0 values MUST be treated as normal transfers and fire the `Transfer` event. {% endhint %} #### adminTransfer Transfers `amount` amount of tokens from address `sender` to address `recipient`, and MUST fire the Transfer event. ```solidity function adminTransfer(address sender, address recipient, uint256 amount) external returns (bool) ``` {% hint style="info" %} NOTE: This function can only be called by the Committee address required in the constructor. This function is designed to create transactions automatically on behalf of token holders if they have been victims of a fraudulent transaction. This method works similarly to the `transferFrom` method. {% endhint %} ### Events #### Transfer MUST trigger when tokens are transferred, including zero value transfers. A token contract which creates new tokens SHOULD trigger a Transfer event with the `from` address set to `0x0` when tokens are created. ```solidity event Transfer(address indexed from, address indexed to, uint256 value) ``` #### Approval MUST trigger on any successful call to `approve(address spender, uint256 value)`. ```solidity event Approval(address indexed owner, address indexed spender, uint256 value) ``` ### IKToken #### internalTransfer Transfers `amount` amount of tokens to address `recipient` internally from `sender`, and MUST fire the `Transfer` event. The function SHOULD `throw` if the message caller's account balance does not have enough tokens to spend. Tokens can be transferred between internal addresses that have completed KYC for both the sender and the recipient using the internalTransfer function. ```solidity function internalTransfer(address sender, address recipient, uint256 amount) external returns (bool) ``` {% hint style="info" %} NOTE: This function can only be called by the Super Admin and the Transfer Router. {% endhint %} #### externalTransfer Transfers `amount` amount of tokens to address `recipient` externally from `sender`, and MUST fire the `Transfer` event. The function SHOULD `throw` if the message caller's account balance does not have enough tokens to spend. The function externalTransfer allows tokens to be transferred between addresses that have only passed the sender's KYC verification process. ```solidity function externalTransfer(address sender, address recipient, uint256 amount) external returns (bool) ``` {% hint style="info" %} NOTE: This function can only be called by the Super Admin and the Transfer Router. {% endhint %} --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.kubchain.com/quickstart/launching-a-token-on-kub/kap-token-interfaces/kap-20.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.