This repository contains Kitty Items, a project that demonstrates current best practice for structuring and writing dapps for deployment to the Flow mainnet using Cadence, Flow Client Library (FCL) and Flow JS and Go SDKs.
Items are hats for your cats but underneath the hood they are non-fungible tokens that exist on the Flow blockchain. Items can be purchased in the front-end marketplace with fungible tokens and eventually applied to ethereum CryptoKitties with ownership validation from an oracle.
- kitty-items - Smart contracts & backend services
- Cadence contracts, transactions, scripts
- Deploy contracts and send transactions with the js-sdk
- Get events from Flow
- kitty-items-web - front-end react application
- Authenticate Flow accounts in your dapp
- Authorization & transaction signing
- Query data with FCL scripts
- kitty-items-oracle - coming soon:tm:
- Account linker
- Oracle service
- Fork it and make your own NFT or FT.
- Use it as a case study/learning experience.
- Take from it as needed.
- Play around with our testnet dApp
On https://github.com/dapperlabs/kitty-items/tree/master/kitty-items-js you will find a backend API written in Typescript / Node.js. This backend has a few purposes:
- Demonstrate how the Flow Javascript SDK can be used to send transactions to the Flow blockchain
- Fetch events from the Flow blockchain and process them such as saving information to a database
In order to accomplish this, we have both a Restful API component as well as a worker.
In the Restful API, you will find several routes that send transactions to the blockchain by using the Flow JS. These transactions are sent by loading a Flow account using a private key from an environment variable.
In the worker, we detect events from the Flow blockchain by running a continuous loop over a set of block ranges. When we detect an event that we’re interested in, we just then run some logic that will further process the data, such as persisting it to a database. In a production setting, we could further augment this data processing by posting a message to a separate message queue so another more specialized worker can work on top of the emitted blockchain event.
The KittyItems smart contracts are written in Cadence, Flow's resource-oriented programming language.
They are used to manage payment, ownership, and selling of items. To ensure composability with other projects on the Flow blockchain they are based on existing standards.
Kibble is KittyItems payment token, based on the Flow Fungible Token standard.
KittyItems are NFTs based on the Flow Non-Fungible Token standard.
KittyItemsMarket is a simple first-sale marketplace contract that sells KittyItems in exchange for Kibble.