NFT project for LETTERs and WORDs (ERC721). Inspired by LOOT, LootLoose and Blockheads.
Currently configured for Ropsten test network. An interface (/interface) to mint and call contract functions is accessible from https://letters-words.vercel.app/. This interface requires MetaMask.
This project is meant to demonstrate interchangable/composable ERC721 LETTER and WORD contracts.
LETTER is a simple enumerated ERC721 contract with two custom functions: tokenURI and claim. There exists 100 of each latin lowercase letter (a...z) available to claim.
Ropsten address: 0x746F97D9BaF77A026AAF00040178bC12493c6Cd5
The tokenURI function generates a Base64 JSON load with a unique name identifier, the corresponding letter, and a generated SVG image based on the LOOT contract.
The claim function allows minting of LETTERs. tokenIds correspond to latin letters direction in a repeating fashion:
| tokenId | letter |
|---|---|
| 1 | a |
| 2 | b |
| ... | ... |
| 26 | z |
| 27 | a |
| 28 | b |
| ... | ... |
| 2599 | y |
| 2600 | z |
Using the standard safeTransferFrom function to send a LETTER to the WORD contract address will mint and assign a new WORD to the sender containing the LETTER. See Word for more details on the contract.
WORD is a more complicated enumerated ERC721 and ERC721Holder which is composed of LETTERs. Each token can contain up to 5 LETTERs, with functions to addLetter, popLetter and convert a letterToWord.
Ropsten address: 0x6b81dBA50F7DEcD088dE06F588E9cBd1Afb9CED9
The addLetter function takes an existing LETTER NFT and creates a new WORD composed of only that letter. The function transfers the LETTER to the contract address, and adds it to a mapping of WORD token IDs to dynamic arrays of LETTER IDs. In order to limit on-chain data and gas costs the limit of letters per WORD is 5. Upon adding a 6th LETTER the first LETTER to be added is popped and transferred to the sender, and the new letter is added to the end of the WORD.
This function pops the last letter in the WORD and sends the token to the designated _sender address. If the WORD only contains 1 LETTER upon popping, the WORD token is burned.
Similar to performing a safeTransferFrom of a LETTER to the WORD contract address, this function performs the same transfer and mints a new WORD owned by the sender.
The interface in the repository is a simple javascript application to allow for UI interaction with the LETTER and WORD contracts. The interface utilizes web3.js for contract interaction. After contract function calls you will need to wait for the transaction to complete then refresh to see changes reflected.
These contracts have not been audited nor extensively tested. It should not be deployed the the mainnet.
- Write unit tests
- Extend interface