Minsc

A Miniscript-based scripting language for Bitcoin contracts

Minsc is a high-level scripting language for expressing Bitcoin Script spending conditions. It is based on the Miniscript Policy language, with additional features and syntactic sugar sprinkled on top, including variables, functions, infix notation, human-readable times and more.

Documentation & live playground are available on the website: https://min.sc

Support development: ⛓️ on-chain or ⚡ lightning via BTCPay

Examples

• A user and a 2FA service need to sign off, but after 90 days the user alone is enough

  pk(user_pk) && (pk(service_pk) || older(90 days))

  :arrow_forward: Try it live

• Traditional preimage-based HTLC

  $redeem = pk(A) && sha256(H);
  $refund = pk(B) && older(10);
  
  $redeem || $refund

  :arrow_forward: Try it live

• Liquid-like federated pegin, with emergency recovery keys that become active after a timeout

  $federation = 4 of [ pk(A), pk(B), pk(C), pk(D), pk(E) ];
  $recovery = 2 of [ pk(F), pk(G), pk(I) ];
  $timeout = older(3 months);
  
  likely@$federation || ($timeout && $recovery)

  :arrow_forward: Try it live

• The BOLT #3 received HTLC policy

  fn bolt3_htlc_received($revoke_pk, $local_pk, $remote_pk, $secret, $delay) {
  $success = pk($local_pk) && hash160($secret);
  $timeout = older($delay);
  
  pk($revoke_pk) || (pk($remote_pk) && ($success || $timeout))
  }
  
  bolt3_htlc_received(A, B, C, H1, 2 hours)

  :arrow_forward: Try it live

• Advanced 2FA where the user has a 2-of-2 setup and the service provider is a 3-of-4 federation

  fn two_factor($user, $provider, $delay) =
  $user && (likely@$provider || older($delay));
  
  $user = pk(desktop_pk) && pk(mobile_pk);
  $providers = [ pk(A), pk(B), pk(C), pk(D) ];
  
  two_factor($user, 3 of $providers, 4 months)

  :arrow_forward: Try it live

More examples are available on https://min.sc.

Local installation

Install Rust and:

$ cargo install minsc

# Compile a minsc file
$ minsc examples/htlc.minsc

# Compile from stdin
$ echo 'pk(A) && older(1 week)' | minsc -

# Dump AST
$ minsc examples/htlc.minsc --ast

Using the Rust API:

use minsc::{parse, run, eval};

let code = "pk(A) && older(1 week)";
let ast = parse(&code).unwrap();
let result = eval(ast).unwrap();
// or parse+eval in one go with `run(&code)`

let policy = result.into_policy().unwrap();
println!("{}", policy);

// also available: into_miniscript() and into_desc()

Full documentation for the Rust API is available here.

JavaScript WASM package

Install with npm install minsc and:

import { run } from 'minsc'

const policy = run('pk(A) && older(1 week)')
const miniscript = run('miniscript(pk(A) && older(1 week))')
const descriptor = run('wsh(miniscript(pk(A) && older(1 week)))')
const address = run('address(wsh(miniscript(pk(A) && older(1 week))))')
const address2 = run('address(pk(A) && older(1 week))')

console.log({ policy, miniscript, descriptor, address, address2 })

License

MIT