Back in 2017, Russell O'Connor at Blockstream published the Simplicity whitepaper. The goal was ambitious: design a clean-slate vision for a smart contract language. One that was more expressive than Bitcoin Script, but safer than other platforms. From the whitepaper to mainnet—eight years later, that vision is now coming to life on the Liquid Network.
Over the years, the Bitcoin developer ecosystem built the rails for payment channels like Lightning and debated new opcodes for Bitcoin Script. Simplicity is not an incremental improvement, but rather a completely parallel alternative to Script. With its arrival, we have for the first time a clean foundation for serious financial applications, without the complexity and patchwork of risks that defined the last era of DeFi.
Simplicity isn’t like Solidity, or Rust, or most modern programming languages, all of which are Turing-complete. Instead, the language was designed to be able to express any finite function while avoiding the risks that come along with Turing completeness. No unbounded loops. No global state. These constraints are valuable to a developer who requires high confidence in the behavior of their application; with Simplicity, every possible outcome to the contract and its fee costs can be known before execution.
This innovation couldn't come at a better time. As Bitcoin expands into global and institutional adoption, the appetite for programmability grows. Simplicity gives the ecosystem an answer, opening the door to smart contracts while maintaining the security and robustness of Bitcoin.
If you’re serious about building next-gen Bitcoin infrastructure, this is where to start.
Want to build covenants, vaults, delegation schemes? Now you can on Liquid. Want to create derivatives, pooled wallets, or tokenless DEXs? That’s possible too.
Because Simplicity is fairly low level, our Rust like, high-level language serves as our developer friendly interface to Simplicity. The high level language lets you write readable, auditable contracts that compile down to the raw Simplicity underneath. As part of our alpha release to Liquid, we’ve rebranded our high-level language from Simfony to SimplicityHL.
This launch wouldn’t have happened without a focused team behind the scenes. Sanket Kanjalkar, Christian Lewe and Andrew Cann's creating and shaping the high-level SimplicityHL language; Sanket and Andrew Poelstra's contributions to rust-simplicity and hal-simplicity. We’re also hiring a developer advocate and smart contract engineers. If building the future of Bitcoin sounds like your thing, we’d love to hear from you.
Liquid is just the beginning. With community feedback, real-world usage, and more tooling, docs, wallet support, and example contracts, our next major goal is to activate on a Bitcoin test network.
Looking forward to seeing what you build!