Learn CLARITY with Real Code Examples

Clarity is a Lisp-like language that is interpreted, not compiled to bytecode, ensuring contracts behave deterministically.

It is decidable, meaning all outcomes of contract execution can be known before running.

Contracts can interact with the Bitcoin blockchain via Stacks.

It prevents runtime errors common in other languages by enforcing strict typing and bounds checking.

Used in DeFi, NFTs, and decentralized applications on Stacks.

define-public -> exposes functions externally

define-constant -> immutable constants

map, list, tuple types for structured data

Contract-to-contract calls

Error handling via (ok ...) and (err ...)

define-public functions for external calls

define-private for internal contract logic

define-constant for immutable values

use maps, lists, tuples for structured storage

ok/err pattern for safe return values

contracts/ - Clarity source files

tests/ - unit and integration tests

scripts/ - deployment scripts

package.json - project configuration

README.md - documentation and usage notes

Write Clarity contracts using define-public and define-private

Use Stacks CLI to deploy to testnet/mainnet

Interact via Hiro Wallet or Stacks.js

Test contracts with mock Bitcoin integration

Monitor execution deterministically

Beginner: simple token contract

Intermediate: NFT minting contract

Advanced: DeFi smart contract with governance

Expert: Bitcoin-integrated financial protocol

Auditor: verify determinism and security

Clarity vs Solidity: Clarity is decidable and predictable, Solidity runs on EVM.

Clarity vs Vyper: Both are safer than Solidity, but Clarity is interpreted and deterministic.

Clarity vs Ink!: Clarity targets Stacks/Bitcoin, Ink! targets Substrate/Wasm.

Clarity vs Ocean SDK: Clarity is smart contract language; Ocean SDK is a data marketplace SDK.

Clarity vs Move: Move is resource-oriented for Diem/Aptos; Clarity is functional and decidable.

2018 – Initial Clarity language release

2019 – Clarity 1.0 formalized

2020 – Extended public/private function support

2021 – Bitcoin integration enhancements

2022–2025 – Continuous updates and ecosystem growth

Stacks: blockchain for Bitcoin integration

STX: native Stacks token

Decidability: predictable execution

DDO: not used; Ocean SDK concept

Public/private function: access control in Clarity