Coders and Decoders

Every data point in merkle tree is made with a key (LeafKey) and value (LeafValue). These keys and values aren't plain data, they are encoded.

You can encode/decode them using coders/decoders from the SDK:

import {LeafValueCoder, LeafKeyCoder} from `@umb-network/toolbox`;

const f = 1234.0000987;
const label = 'ETH-USD';

// encode data for leaf:
const leafData: Buffer = LeafValueCoder.encode(f, label);

// decode data
const originalValue = LeafValueCoder.decode(leafData.toString('hex'), label);

// encoder accepts Buffer or hex string
const encodedKey: Buffer = LeafKeyCoder.encode('ETH-USD');

const decodedKey: string = LeafKeyCoder.decode(encodedKey);


Currently we are supporting:

  • floating point numbers: this is default type of any value, it is basically JS number
  • fixed data: any data in hex format

Types are determined by labels.

Floating points number

This is default type for any value. Floating point numbers are encoded to 18 decimal precision numbers - uint256 solidity type. This is compatible with blockchain standard of representing amounts.

Fixed data

  • This type of data is saved as is. Leaves for this type start with the prefix SDK.constants.FIXED_NUMBER_PREFIX.