@ckb-ccc/core

The foundational CCC primitives — Transaction, Script, Address, Client, Signer, and more.

@ckb-ccc/core is the base layer of CCC. It contains all CKB data types, encoders, hashers, and the abstract Signer / Client interfaces used by every higher-level package.

Most projects do not need to install @ckb-ccc/core directly. Use @ckb-ccc/shell for Node.js or @ckb-ccc/connector-react for React — both re-export everything from core.

Installation

npm install @ckb-ccc/core

yarn add @ckb-ccc/core

pnpm add @ckb-ccc/core

Imports

import { ccc } from "@ckb-ccc/core";

Exported modules

@ckb-ccc/core re-exports the following sub-modules under the ccc namespace:

Module	Contents
`address`	`Address`, `AddressLike`, address parsing and formatting
`bytes`	`bytesFrom`, `bytesTo`, byte array utilities
`ckb`	`Transaction`, `Script`, `Cell`, `CellInput`, `CellOutput`, `OutPoint`, `WitnessArgs`
`client`	`Client` (abstract), `ClientPublicMainnet`, `ClientPublicTestnet`
`fixedPoint`	`fixedPointFrom`, `fixedPointToString` — CKB capacity in shannons
`hasher`	`hashCkb`, `Hasher` — CKB Blake2b hashing
`hex`	`hexFrom`, `HexLike`, hex encoding helpers
`jsonRpc`	`RequestorJsonRpc` — low-level JSON-RPC client
`keystore`	`KeyStore` — encrypted key storage
`molecule`	Molecule codec primitives
`num`	`numFrom`, `numFromBytes`, `numToBytes`, `numLeToBytes` — numeric conversions
`signer`	`Signer` (abstract), `SignerInfo`, `SignerType`, `SignerSignType`
`utils`	Miscellaneous helpers

Key classes

Transaction

The primary type for building CKB transactions:

// Build a CKB transfer transaction
const tx = ccc.Transaction.from({
  outputs: [{ lock: toLock, capacity: ccc.fixedPointFrom(amount) }],
});

await tx.completeInputsByCapacity(signer);
await tx.completeFeeBy(signer);
const txHash = await signer.sendTransaction(tx);

Important methods:

Method	Description
`Transaction.from(like)`	Create from a plain object
`tx.addInput(cell)`	Add a cell input
`tx.addOutput(output, data?)`	Add a cell output
`tx.completeInputsByCapacity(signer)`	Auto-select inputs to cover capacity
`tx.completeFeeBy(signer, feeRate?)`	Add a change output and compute fee
`tx.addCellDepInfos(client, deps)`	Resolve and add cell dependencies
`signer.sendTransaction(tx)`	Sign and broadcast

Script

const script = ccc.Script.from({
  codeHash: "0x...",
  hashType: "type",
  args: "0x...",
});

script.eq(otherScript); // structural equality

Address

const addr = await ccc.Address.fromString(
  "ckb1qzda0cr08m85hc8jlnfp3gog...",
  client,
);
const { script, prefix } = addr;

Signer (abstract)

The Signer abstract class is implemented by every wallet integration. Key members:

abstract class Signer {
  readonly client: Client;

  abstract getInternalAddress(): Promise<string>;
  abstract getRecommendedAddressObj(preference?: unknown): Promise<Address>;
  abstract signTransaction(tx: Transaction): Promise<Transaction>;

  async sendTransaction(tx: Transaction): Promise<Hex>;
  async findCells(filter, withData?, order?, limit?): AsyncGenerator<Cell>;
}

Client (abstract)

// Connect to public testnet
const client = new ccc.ClientPublicTestnet();

// Connect to public mainnet
const client = new ccc.ClientPublicMainnet();

// Connect to a custom node
const client = new ccc.ClientPublicTestnet("https://my-node.example.com/rpc");

Key functions

// Convert any value to a fixed-point CKB capacity (shannons)
const capacity = ccc.fixedPointFrom("100"); // 100 CKB = 10_000_000_000n shannons

// Hash data with CKB's Blake2b
const hash = ccc.hashCkb(data);

// Encode to hex
const hex = ccc.hexFrom(bytes);

// Numeric conversion
const n = ccc.numFrom("0xff"); // BigInt
const bytes = ccc.numToBytes(n, 8); // little-endian Uint8Array

// Byte conversions
const arr = ccc.bytesFrom("0xdeadbeef");
const str = ccc.bytesTo(arr, "utf8");

@ckb-ccc/core

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