CashScript is a high-level programming language for smart contracts on Bitcoin Cash. It offers a strong abstraction layer over Bitcoin Cash' native virtual machine, Bitcoin Script. Its syntax is based on Ethereum's smart contract language Solidity, but its functionality is very different since smart contracts on Bitcoin Cash differ greatly from smart contracts on Ethereum. For a detailed comparison of them, refer to the blog post Smart Contracts on Ethereum, Bitcoin and Bitcoin Cash.
This repository contains the code for the CashScript compiler & command line tool under packages/cashc/
. This repository also contains the code for the CashScript TypeScript SDK under packages/cashscript/
. The source code of the CashScript.org website is included under website/
. Visit the website for a detailed Documentation on the CashScript language and SDK.
CashScript is a high-level language that allows you to write Bitcoin Cash smart contracts in a straightforward and familiar way. Its syntax is inspired by Ethereum's Solidity language, but its functionality is different since the underlying systems have very different fundamentals. See the language documentation for a full reference of the language.
CashScript features a compiler as a standalone command line tool, called cashc
. It can be installed through npm and used to compile .cash
files into .json
artifact files. These artifact files can be imported into the CashScript TypeScript SDK (or other SDKs in the future). The cashc
NPM package can also be imported inside JavaScript files to compile .cash
files without using the command line tool.
npm install -g cashc
Usage: cashc [options] [source_file]
Options:
-V, --version Output the version number.
-o, --output <path> Specify a file to output the generated artifact.
-h, --hex Compile the contract to hex format rather than a full artifact.
-A, --asm Compile the contract to ASM format rather than a full artifact.
-c, --opcount Display the number of opcodes in the compiled bytecode.
-s, --size Display the size in bytes of the compiled bytecode.
-?, --help Display help
The main way to interact with CashScript contracts and integrate them into applications is using the CashScript SDK. This SDK allows you to import .json
artifact files that were compiled using the cashc
compiler and convert them to Contract
objects. These objects are used to create new contract instances. These instances are used to interact with the contracts using the functions that were implemented in the .cash
file. For more information on the CashScript SDK, refer to the SDK documentation.
npm install cashscript
import { Contract, ... } from 'cashscript';
Using the CashScript SDK, you can import contract artifact files, create new instances of these contracts, and interact with these instances:
...
// Import the P2PKH artifact
import P2PKH from './p2pkh-artifact.json' with { type: 'json' };
// Instantiate a network provider for CashScript's network operations
const provider = new ElectrumNetworkProvider('mainnet');
// Create a new P2PKH contract with constructor arguments: { pkh: pkh }
const contract = new Contract(P2PKH, [pkh], provider);
// Get contract balance & output address + balance
console.log('contract address:', contract.address);
console.log('contract balance:', await contract.getBalance());
// Call the spend function with the owner's signature
// And use it to send 0. 000 100 00 BCH back to the contract's address
const txDetails = await contract.functions
.spend(pk, new SignatureTemplate(keypair))
.to(contract.address, 10000)
.send();
console.log(txDetails);
...
If you want to see CashScript in action and check out its usage, there are several example contracts in the examples/
directory. The .cash
files contain example contracts, and the .ts
files contain example usage of the CashScript SDK to interact with these contracts.
The "Hello World" of CashScript contracts is defining the P2PKH pattern inside a contract, which can be found under examples/p2pkh.cash
. Its usage can be found under examples/p2pkh.ts
.
To run the examples, clone this repository and navigate to the examples/
directory. Since the examples depend on the SDK, be sure to run npm install
or yarn
inside the examples/
directory, which installs all required packages.
git clone [email protected]:CashScript/cashscript.git
cd cashscript/examples
npm install
All .ts
files in the examples/
directory can then be executed with tsx
.
npm install -g tsx
tsx p2pkh.ts
All .js
files can be executed with node
.
node p2pkh.js