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Quick Start (5 min)

Welcome to the Nervos CKB ecosystem! This guide will help you set up your local development environment in just a few minutes. After that, you can explore the various paths to build on CKB.

Start Your Local Devnet​

We recommend using offCKB to quickly set up a local CKB Devnet for development.

This setup is useful when you want to build a dApp or deploy and test a Script on a local chain. If you only want to learn CKB concepts, develop a Script with local testing tools, or run a Mainnet or Testnet node, you can skip to Choose Your Path.

Install OffCKB​

OffCKB requires Node.js 20 or later. Check your installed version:

node -v

If the version is below v20.0.0, install a current Node.js LTS release before continuing.

npm install -g @offckb/cli
info

Throughout this documentation, we use offckb/cli version >=0.4.0. You can always run the above command to update to the latest version.

Start the Devnet​

offckb node

Your local CKB blockchain is now running. Use the proxy RPC endpoint at http://127.0.0.1:28114 as the default for local development. It forwards requests to the node and records failed transactions for debugging. The direct RPC endpoint at http://127.0.0.1:8114 bypasses the debugging proxy.

Keep this terminal open while you use the Devnet, and open a second terminal for the commands you run next. To stop the chain, press CTRL+C. To resume where you left off, run offckb node again.

note

This Devnet runs only on your computer. Its transactions will not appear in public Testnet or Mainnet explorers.

View Pre-funded Accounts​

In the second terminal, list the pre-funded Devnet accounts:

offckb accounts

OffCKB also provides built-in Scripts like Omnilock and Spore-contract, and useful debugging tools. Check out the OffCKB documentation for more details.

Reset the Devnet​

If you need to start fresh with a new chain, first stop the running node by pressing CTRL+C. Then run:

offckb clean
caution

Cleaning the Devnet creates a new local chain. Transaction hashes and deployed Script OutPoints from the previous chain will no longer be valid.

Choose Your Path​

Choose the path that matches what you want to do on CKB:

🚀 Build a DApp​

Learn how to build decentralized applications that interact with the CKB blockchain:

🔐 Write Smart Contracts (Scripts)​

CKB supports several languages for writing on-chain smart contracts (Scripts), but Rust is currently recommended for production use because of its performance, memory safety, and mature tooling.

Unlike an EVM contract, a deployed CKB Script does not have a contract address. Its code is stored in a Cell and identified by an OutPoint; transactions include that reference in a CellDep. See Deploy a CKB Smart Contract for details.

Get started with:

📚 Learn Core Concepts​

Deep dive into CKB's unique architecture:

  • How CKB Works — Understand CKB's design philosophy
  • Cell Model — Learn about CKB's UTXO-like data model
  • CKB-VM — Explore the RISC-V based virtual machine

🖥️ Run a CKB Node​

  • Run a Node — Operate a persistent CKB Mainnet or Testnet node

Additional Resources​

  • OffCKB CLI — Full documentation for the OffCKB tool
  • CCC SDK — CKB's official JavaScript/TypeScript SDK for building dApps
  • CKB CLI — Command-line tool for interacting with CKB nodes

Happy building! 🎉