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Overview

You can use the dedicated typescript SDK @opcat-labs/cat-sdk to integrate the standard token protocol with your smart contracts or dApps on the OP_CAT Layer.

Installation

For npm users

npm install @opcat-labs/cat-sdk

For yarn users:

yarn add @opcat-labs/cat-sdk

Architecture

The CAT protocol is designed to work on the OP_CAT layer network. To construct decentralized applications based on the CAT protocol, here's our recommended architecture design.

App​

Let’s begin with the idea that you’re planning to develop an app with certain features that enable users to interact with CAT20 or CAT721 tokens.

Signer​

Since there are many wallets that your app wants to allow users to connect to, you can just use interfaces of Signer to simplify the process of signing transactions. By abstracting the wallet as the signer, the application can be decoupled from the implementation of signing transactions from specific wallets.

Feature​

Your app or library can offer some features that can be easily accessed through simple APIs by other parts of your application or even third-party developers without revealing the intricate details of the underlying structure of transactions. For instance, if you want to provide a feature, you might need to write some code within your feature function to handle transaction creation, signing, and broadcasting, as well as UTXO management tasks. This could involve multiple transactions within a single feature.

SmartContract​

By simply using sCrypt’s DSL, you can effortlessly write smart contracts. In general terms, an sCrypt smart contract represents how you want to control the spending conditions of a specific UTXO. You can treat smart contracts as Bitcoin script that you can read and write without having to grapple with the steep learning curve of the Bitcoin Stack-based virtual machine.

Bitcoin Script​

All of the sCrypt smart contracts would be compiled into Bitcoin scripts and included in the corresponding transactions. These scripts would then be verified by miners when they include these transactions in blocks.

SDK Summary

The cat-sdk offers some useful APIs that can be used when building applications. Additionally, it provides a good example that adheres to the architecture design previously discussed.

  • Features: On a high level, this SDK offers some fundamental functionalities to interact with CAT20 and CAT721 protocol tokens, including Deploy, Mint, Transfer, Burn, and Freeze. These APIs can be found in the src/features folder.

  • Smart Contracts: On a fundamental level, this SDK offers all the essential smart contracts written in the sCrypt DSL, which can be compiled into Bitcoin scripts. If you’re interested in learning how to create your own on-chain smart contracts, you should thoroughly examine these contracts in the src/contracts folder.

You can access the source code of the SDK from here. We hope you had a wonderful journey with the CAT protocol.