Scrypt Boilerplate
Note: Modified to use @radiantblockchian/radjs for testnet/superAssetR100.js
sCrypt Project Boilerplate
https://github.com/RadiantBlockchain-Community/scrypt-boilerplate
Prerequisites
Make sure you have the sCrypt IDE installed. sCrypt IDE is a tool for developers to write, test, deploy, call, and debug sCrypt smart contracts.
Guide
sCrypt is a high-level programming language for writing smart contracts on Bitcoin SV. This project provides examples to help developers learn and integrate sCrypt smart contracts to their Javascript-based projects. Our recommended procedure of developing smart contract based applications is as follows:
Contract Development and Test
Contract Integration and Application Launch
After developing and unit testing the smart contracts, the next step is to integrate them into your application which is written in other languages such as Javascript or Python. Integration tests should be run on Bitcoin SV Testnet or Scaling Test Network(STN) before launching the application to the public on mainnet.
Quickstart
npm install
npm test
Directory layout
For each contract x
, a source file is at contracts/x.scrypt
, a test file is at tests/js/x.scrypttest.js
, and a deployment file is at testnet/x.js
.
.
├── contracts # sCrypt contract files
│ ├── accumulatorMultiSig.scrypt #
│ ├── ackermann.scrypt #
│ ├── acs.scrypt # A contract which can be spent by anyone but only to a specific address
│ ├── advancedCounter.scrypt # Use external UTXOs to pay contract tx fees using sighash ANYONECANPAY
│ ├── advancedTokenSale.scrypt # Sambe as above, but for token sale contract
│ ├── asm.scrypt # Embed Script directly into sCrypt
│ ├── auction.scrypt #
│ ├── binaryOption.scrypt #
│ ├── cltv.scrypt #
│ ├── cointoss.scrypt #
│ ├── cointossxor.scrypt #
│ ├── conwaygol.scrypt #
│ ├── counter.scrypt # Count the number of times a function has been called to showcase
│ ├── ec.scrypt #
│ ├── ecdsa.scrypt #
│ ├── demo.scrypt # "hello world" contract
│ ├── faucet.scrypt #
│ ├── forward.scrypt #
│ ├── hashpuzzlep2pkh.scrypt # combining and p2pkh contracts
│ ├── kaggle.scrypt #
│ ├── lottery.scrypt #
│ ├── mast.scrypt #
│ ├── merkleToken.scrypt # Token based on Merkle Tree
│ ├── merkleTree.scrypt # validation and updating
│ ├── nonFungibleToken.scrypt #
│ ├── oracle.scrypt #
│ ├── p2pkh.scrypt # contract written in sCrypt
│ ├── p2sh.scrypt #
│ ├── perceptron.scrypt #
│ ├── perceptron2.scrypt #
│ ├── rabin.scrypt # to import off-chain data into a contract via oracle
│ ├── recurring.scrypt #
│ ├── rpuzzle.scrypt #
│ ├── schnorr.scrypt #
│ ├── rps.scrypt # Rock Paper Scissors
│ ├── simpleBVM.scrypt #
│ ├── spvToken.scrypt #
│ ├── statecounter.scrypt #
│ ├── stateStruct.scrypt # Recommended way to implement a stateful contract using struct
│ ├── sudoku.scrypt #
│ ├── svd.scrypt #
│ ├── tictactoe.scrypt # onchain p2p gaming
│ ├── timedcommit.scrypt # : Trustless contracting by combining on-chain and off-chain transactions
│ ├── token.scrypt # by storing token map as contract state in a single UTXO
│ ├── tokenSale.scrypt # Selling tokens for bitcoins using
│ ├── tokenSwap.scrypt # Merkle tree-based token and bitcoin swap
│ ├── tokenUtxo.scrypt #
│ ├── treeSig.scrypt #
│ └── util.scrypt # utility functions and constants
├── testnet # examples to deploy contract and call its function on testnet
└── fixture
└── autoGen # contract description json files
└── tests # contract test files
├── js # Javascript unit tests
└── ts # Typescript unit tests
How to write test for an sCrypt contract
The major steps to write a sCrypt test are exemplified by tests/demo.scrypttest.js
.
Install and import / require
scryptlib
libary, which is a javascript SDK for integrating sCrypt smart contract.
npm install scryptlib
import { buildContractClass } from 'scryptlib';
Use the imported function
buildContractClass
to get a reflected contract, which has same properties and methods as defined in the specified sCrypt contract.
// build a contract class
// either by compiling the contract from scratch
const Demo = buildContractClass(compileContract('demo.scrypt'))
// or from contract desc file if it's already generated from compilation
const Demo = buildContractClass(loadDesc('demo_desc.json'))
Note that demo_desc.json
is the description file name of the compiled contract, which will be generated automatically if you run npm run watch
and its name follows the rule $contractName_desc.json
.
Initialize the contract.
demo = new Demo(4, 7);
Write tests for the instantiated contract as you would do in Javascript.
const result = demo.add(7 + 4).verify()
expect(result.success, result.error).to.be.true
How to run tests locally
Run using sCrypt IDE
Run unit tests file within the editor/explorer context menu.

Run from console
Tests could also be run from the console by executing npm test
, just like regular Javascript/TypeScript tests.
How to deploy a contract and interacte with it
Deploy by writing javascript/typescript code
Provide a private key with funds in
privateKey.js
const key = '$YOUR_PRIVATE_KEY_HERE'
Deploy a contract and call its function by issuing
node testnet/demo.js
Output like the following will appear in the console. And you have successfully deployed a contract and called its function on Bitcoin. Sweet!
locking txid: 8d58ff9067f5fa893b5c695179559e108ebf850d0ce4fd1e42bc872417ffd424
unlocking txid: c60b57e93551a6c52282801130649c6a97edcca5d2b28b8b4ae2afe0ee59bf79
Succeeded on testnet
It is strongly recommended to test your contract on testnet first, before deploying it on mainnet. By default, deployment is on testnet. To switch to mainnet, simply modify API_PREFIX
in helper.js
.
const API_PREFIX = 'https://api.whatsonchain.com/v1/bsv/main'
// const API_PREFIX = 'https://api.whatsonchain.com/v1/bsv/test' for Testnet
// const API_PREFIX = 'https://api.whatsonchain.com/v1/bsv/stn' for Scaling Test Net
Before deploying a contract, make sure the latest contract has been compiled to a description json file, which is what will get deployed. This could be done automatically by running a daemon process with command npm run watch
. It will monitor a contract file's change and recompile it when necessary. All generated description files are located at testnet/fixture/autoGen
. Make sure it's up to date with the contract before deployment.
Deploy by using sCrypt IDE deploy feature
IDE provides a universal UI interface. You can deploy the contract with one click by simply filling in the relevant parameters. You can call the public function of the contract with the click of a button without writing a line of code.

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