What is Stacks (STX)?
- Author
- CRYPTO PORT Editorial
- Published
- Updated
- Reading time
- 6 min
In short
Stacks is a blockchain whose goal is to bring smart contracts to Bitcoin without changing Bitcoin itself. Its consensus anchors its own history into Bitcoin blocks so it can inherit Bitcoin's settlement. Locking STX for a period earns BTC through a mechanism called Stacking.
Key points
- Adds a smart contract layer on top of Bitcoin without altering the Bitcoin protocol
- Uses Proof of Transfer, writing its own blocks into Bitcoin transactions
- Locking STX to participate in consensus pays rewards in BTC
- Its contract language, Clarity, emphasises being able to reason about behaviour before execution
Definition
A blockchain that anchors its records into Bitcoin so it can rely on Bitcoin's settlement while running smart contracts.
Bitcoin deliberately keeps a narrow feature set and does not run complex smart contracts directly. Stacks' approach is to place a contract execution layer alongside it without changing Bitcoin at all.
Its consensus is called Proof of Transfer. Participants bidding to produce a block spend BTC, and that spend is recorded in a Bitcoin block, pinning the Stacks history into Bitcoin — rewriting it would require reorganising Bitcoin itself. The BTC spent is distributed to participants who have locked STX.
That distribution is Stacking. Lock STX for a period to help maintain consensus and you receive BTC as a reward. Earning a BTC-denominated reward without running mining hardware is what sets this apart from staking on other chains.
Contracts are written in Clarity, which is interpreted rather than compiled, with the stated aim of making it easier to determine what a contract will do before it runs. A more recent upgrade called Nakamoto increased block production frequency, and sBTC was introduced as a way to use bitcoin within Stacks.
Watch out for
- · Stacking locks STX for a fixed period, during which it cannot be withdrawn or sold
- · Because records are anchored to Bitcoin, confirmation times and costs are affected by conditions on Bitcoin
- · Using BTC within Stacks introduces additional assumptions; do not deposit without checking how the mechanism works
Frequently asked questions
Is it a Bitcoin layer 2?
It depends on how the term is defined. Stacks is a separate chain with its own blocks and consensus that anchors its history into Bitcoin. It does not have Bitcoin verify its execution the way a rollup does.