@dedot/merkleized-metadata

Merkleized Metadata Utilities - Implementing the RFC-0078 Merkleized Metadata specification.

Overview

This package provides utilities for:

• Calculate metadata hash/digest
• Generate proofs for extrinsic, extrinsic payload or extrinsic parts

Usage

Calculating Metadata Hash/Digest

import { DedotClient, WsProvider } from 'dedot';
import { MerkleizedMetadata } from 'dedot/merkleized-metadata';

// Create a dedot client
const client = await DedotClient.new(new WsProvider('wss://rpc.polkadot.io'));

// Get metadata from the client
const metadata = client.metadata;

// Define chain-specific information
const chainInfo = {
  // These can be omitted as they'll be fetched from metadata
  // specVersion: client.runtimeVersion.specVersion,
  // specName: client.runtimeVersion.specName,
  // ss58Prefix: 0, // Polkadot

  // These are required
  decimals: 10,
  tokenSymbol: 'DOT'
};

// Create a merkleizer instance
const merkleizer = new MerkleizedMetadata(metadata, chainInfo);

// Calculate metadata hash
const hash = merkleizer.digest();
console.log('Metadata Hash:', hash);

Generating Proofs for Extrinsics

import { MerkleizedMetadata } from 'dedot/merkleized-metadata';

// Create a merkleizer instance
const merkleizer = new MerkleizedMetadata(metadata, chainInfo);

// Generate proof for an extrinsic
const extrinsicHex = '0x...'; // Hex-encoded extrinsic
const proof = merkleizer.proofForExtrinsic(extrinsicHex);

// Generate proof for extrinsic payload
const txPayload = '0x...'; // Hex-encoded extrinsic payload
const proof3 = merkleizer.proofForExtrinsicPayload(txPayload);

// Generate proof for extrinsic parts
const callData = '0x...'; // Hex-encoded call data
const includedInExtrinsic = '0x...'; // Hex-encoded extrinsic extra
const includedInSignedData = '0x...'; // Hex-encoded signed extra
const proof2 = merkleizer.proofForExtrinsicParts(callData, includedInExtrinsic, includedInSignedData);

MerkleizedMetadata

Main class for calculating metadata hashes and generating proofs.

• Constructor: new MerkleizedMetadata(metadata, chainInfo)

  • metadata: Metadata object, hex string, or Uint8Array
  • chainInfo: Chain-specific information (some fields can be omitted as they'll be fetched from metadata)

• Methods:

  • digest(): Calculate metadata hash and return as Uint8Array
  • proofForExtrinsic(extrinsic, additionalSigned?): Generate proof for an extrinsic
  • proofForExtrinsicPayload(txPayload): Generate proof for extrinsic payload
  • proofForExtrinsicParts(callData, includedInExtrinsic, includedInSignedData): Generate proof for extrinsic parts

License

Apache-2.0