# Token-Standard

Check standards source code [here](https://github.com/Lambda-BTC-Protocol/contracts/tree/master/standards).

Why do we need a token standard? Simple because everything is a smart contract, your favorite token in this protocol is just your balance stored somewhere, I mean what else is money anyway. And to make a common interface for every smart contract which should behave like a token we use a token-standard. Like ERC-20 for example in Ethereum.

This means any contract which implements the necessary function is at the bare minimum a token. There can be more functionality on top, or some clever ways to implement the functions. The main thing, though, is that every dapp existing now or in the future can interact with your token / contract. To give a proper example: the AMM currently available operates with this standard in mind, therefore every token you create which has the token-standard functions, can be swapped at the AMM.

## LRC-20

#### Mutations

`transfer(to: string, value: number)`\
this function transfers from the `sender` to the `to` the amount of `value`. It should check to see if the `sender` has enough balance.

`transferFrom(from: string, to: string, value: number)`\
this behaves similar to the above. However, it is more powerful and allows every token interaction imaginable. Read here [#why-does-lrc-20-have-an-approve](https://docs.lambdaprotocol.io/introducing-lambda/faq#why-does-lrc-20-have-an-approve "mention") to see why it is necessary. Checks if the `from` has given the `sender` the allowance to transfer the token amount of `value` out of his wallet to the `to` wallet. Reduces the `allowance` after successful transfer

`approve(spender: string, value: number)`\
allows the `spender` to transfer the token out of the `sender`s wallet with the `transferFrom` function

#### Queries

`name() returns string`\
the name of the token

`symbol() returns string`\
the symbol of the token 

`decimals() returns number`\
the number of decimals, because we only use integer values internally to prevent rounding errors

`totalSupply() returns number`\
the current supply of tokens

`balanceOf(owner: string) returns number`\
the balance of the `owner`

`allowance(owner: string, spender: string) returns number`\
the allowance set by the `owner` for the `spender`

#### Events

`Transfer(from, to, value)`\
logged when a transfer happened

`Approval(owner, spender, value)`\
logged when an approval happened

## LRC-721

TBA