Learn more about the Stacks 2.0 blockchain


Stacks 2.0 is a layer-1 blockchain that connects to Bitcoin and brings smart contracts and decentralized apps to it. Smart contracts and apps developed on the Stacks platform are natively integrated with the security, stability, and economic power of Bitcoin.


Read more about the features provided by the Stacks 2.0 blockchain.

A detailed comparison of the Stacks blockchain to other blockchain technologies is available at the Stacks Foundation blog.

Consensus mechanism

Stacks 2.0 implements a new mining mechanism called Proof of Transfer ("PoX"). PoX is a consensus algorithm between two blockchains. It uses an established blockchain (in this case Bitcoin) to secure a new blockchain (Stacks).

PoX connects to Bitcoin with a 1:1 block ratio, meaning anything that happens on the Stacks blockchain can be verified on the Bitcoin Blockchain.

Instead of burning electricity on proof of work, PoX reuses already minted bitcoins as "proof of computation" and miners represent their cost of mining in bitcoins directly.

Graphic for: Proof of Transfer
Proof of Transfer
Understand the proof-of-transfer consensus mechanism


Mining is required to make the network usable, trustworthy, and secure. Miners verify incoming transactions, participate in the consensus mechanism, and write new blocks to the blockchain.

To incentivize mining, miners receive freshly minted Stacks (STX) tokens if they win the bid for becoming the leader of the next round.

Graphic for: Mining
A guide to mining on Stacks 2.0


Bitcoins used for miner bids are sent to a set of specific addresses corresponding to Stacks (STX) tokens holders that are actively participating in consensus ("Stackers"). Thus, rather than being destroyed, the bitcoins consumed in the mining process go to productive Stacks holders as a reward based on their holdings of Stacks and participation in the Stacking algorithm.

Stackers have to lock up their Stacks (STX) tokens for a certain period of time.

Graphic for: Stacking
Introduction to the reward mechanism of Proof-of-Transfer

Smart contracts

Clarity is a new language for smart contracts on the Stacks 2.0 blockchain. The Clarity smart contract language optimizes for predictability and security.

Stacks 2.0 anchors clarity smart contracts to Bitcoin making it possible for smart contracts to operate based on actions seen on the bitcoin blockchain.

Clarity is distinct from other languages designed for writing smart contracts in a few ways:

  • Predictability: The Clarity language uses precise and unambiguous syntax that allows developers to predict exactly how their contracts will be executed.
  • Security: The Clarity language allows users to supply their own conditions for transactions that ensure that a contract may never unexpectedly transfer a token owned by a user.
  • No compiler: Contracts written in Clarity are broadcasted on the Stacks blockchain exactly as they are written by developers. This ensures that the code developers wrote, analyzed, and tested, is exactly what gets executed.
Graphic for: Clarity overview
Clarity overview
Overview and guides for getting started with Clarity

Decentralized apps

Stacks 2.0 enabled building decentralized apps that are user-owned and avoid centralized servers.

Graphic for: Build apps with Stacks
Build apps with StacksAuthenticate users, sign transactions and store data with the Stacks blockchain
Build apps with Stacks
Graphic for: Authentication
AuthenticationRegister and sign in users with identities on the Stacks blockchain
Graphic for: Transaction signing
Transaction signingPrompt users to sign and broadcast transactions to the Stacks blockchain
Transaction signing
Graphic for: Data storage
Data storageSave and retrieve data for users with Gaia
Data storage


Read one of our guides to understand the ins and outs of the Stacks 2.0 blockchain.

AccountsGuide to Stacks 2.0 accounts
TransactionsGuide to Stacks 2.0 transactions
NetworkGuide to the Stacks 2.0 network
MicroblocksGuide to Stacks Microblocks

Try it out

Ready to get started with Stacks? Try one of our existing tutorials:

Managing accountsLearn how to generate and review accounts
Managing accounts
Sending tokensLearn how to transfer tokens
Sending tokens
Running a testnet nodeSet up and run a testnet node with Docker
Running a testnet node
Running a regtest nodeLearn how to set up and run a regtest node
Running a regtest node

Developer tooling

Developing on the Stacks blockchain is much simpler with the our tooling.

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