A Verto-compatible SmartWeave contract for NFTs.

NFT.js

export function handle (state, action) {
    let owner = state.owner
    const input = action.input
    const caller = action.caller
    const contact = action.contact
  
    if (input.function === 'transfer') {
      const target = input.target
  
      if (!target || (caller === target)) {
        throw new ContractError('Invalid target for transfer')
      }
  
      if (caller !== owner) {
        throw new ContractError(`Caller does not own the item`)
      }

      owner = target

      return { state }
    }
    
    if (input.function === 'balance') {
      const target = input.target
      const ticker = state.ticker
  
      if (typeof target !== 'string') {
        throw new ContractError('Must specificy target to get balance for')
      }
  
      return { result: { target, ticker, balance: (target === owner) ? 1 : 0 } }
    }
  
    throw new ContractError(`No function supplied or function not recognised: "${input.function}"`)
}

Example initial state:

{
    "ticker": "OWOCEAN",
    "owner": "vLRHFqCw1uHu75xqB4fCDW-QxpkpJxBtFD9g4QYUbfw",
    "data": "00gT33gZpgWK4HMS0AuEy8OXC5_xyQjyJCsX6ps0iuM"
}