22388o / bsl

Bitcoin Scripting Language

Development

To run tests raco test . for now. No package support is provided yet.

Introduction

Bitcoin Scripting Language (BSL) is useful for writing bitcoin contracts that can be tested with a simulated blockchain. Both bitcoin contracts and the blockchain are controlled by BSL.

BSL enables writing contracts that use high level concepts like bitcoin standard scripts and tweaked keys and provides a language to enable productive discussions around contract sepcifications.

BSL is best described with some examples.

Example 1: Alice receives coinbase output as P2PKH

blockchain initialize
keypair alice
coinbase_tx = transaction (
    txid: 1
    input: nil
    output: p2pkh alice
)
blockchain block (
    height: 1
    transactions: [coinbase_tx]
)

blockchain initialize creates a simulated blockchain.

keypair alice creates a new keypair that is assigned to alice.

transaction is used a construct a transaction. Here we create a coinbase transaction that takes no input and has a p2pkh output.

p2pkh alice generated the bitcoin scriptPubKey such that alice's public key can generate the required scriptSig to spend the output.

blockchain block is a construct that moves the blockchain forward to the given height with the list of transactions listed.

Example 2: Alice spends coinbase to Alice and Bob multisig

This example continues from example 1.

First Alice spends the coinbase transaction from example 1 to a multisig output.

keypair bob
alice_to_alice_and_bob = transaction (
    input: coinbase_tx signed by alice
    outputs: [
        multisig 2 of 2 alice and bob
    ]
)
blockchain block (
    height: 2
    transactions: [alice_to_alice_and_bob]
)

multisig 2 of 2 alice and bob is a construct that generates the scriptPubKey that can be spent once signed by both alice and bob.