Blockstream has officially launched Simplicity, a new smart contract programming language designed to enhance Bitcoin's functionality beyond being just a store of value.

These design constraints facilitate static analysis, ensure predictable execution paths and fee costs, and support formal verification, making Simplicity more appealing for institutional use.

Despite potential challenges, including the conservative nature of the Bitcoin community regarding functionality changes, Blockstream is working on SimplicityHL to ease the development process.

Simplicity is intended to work with Blockstream's Liquid layer-2 protocol and serves as a viable alternative to Ethereum's Solidity, specifically targeting decentralized finance (DeFi) and programmable money.

The language emphasizes security and composability, offering a formal and deterministic approach to smart contract logic that aligns with Bitcoin's unspent transaction output (UTXO) architecture.

Unlike Turing-complete languages, Simplicity is not Turing-complete, which means it avoids unbounded loops and global mutable states, focusing instead on finite functions.

Simplicity can support various financial applications, including covenants, vaults, and delegation schemes, as well as market primitives like cash-settled derivatives and pooled wallets.

However, the language runs on the Liquid sidechain, which is a federated network, raising potential concerns about centralization and censorship.

The framework allows for contracts to be mathematically verified before execution, catering to institutional needs for auditability and regulatory compliance, which have been challenging with existing blockchain solutions.

If successfully adopted on Bitcoin's main layer in the future, Simplicity could solidify Bitcoin's role as a programmable settlement layer for institutional-grade finance.

Andrew Poelstra, Blockstream's Head of Research, believes that Simplicity extends Bitcoin's utility beyond being a store of value, positioning it as a platform for financial infrastructure.

This announcement was made on July 31, 2025, and the concept was initially proposed by researcher Russell O’Connor in 2017.