HashLock

Hash lock implementation for atomic swaps

HashLock

Represents a hash lock used in cross-chain atomic swaps. Supports both single-fill and multiple-fill orders using Merkle trees.

Constructor

new HashLock(val: string)

val · string · required

32-byte hex-encoded hash value

Use static factory methods (forSingleFill, forMultipleFills) instead of calling the constructor directly.

Static Properties

Web3Type · string

Returns “bytes32” - the Solidity type for hash locks

Static Methods

forSingleFill

Create a HashLock for a single-fill order by hashing a secret.

HashLock.forSingleFill(secret: string): HashLock

secret · string · required

32-byte hex-encoded secret value

Returns: HashLock containing keccak256(secret)

Example:

const secret = "0x1234..." // 32 bytes hex
const hashLock = HashLock.forSingleFill(secret)

forMultipleFills

Create a HashLock for multiple-fill orders using a Merkle tree.

HashLock.forMultipleFills(leaves: MerkleLeaf[]): HashLock

leaves · MerkleLeaf[] · required

Array of Merkle leaves (must be greater than 2)

Returns: HashLock containing Merkle root with embedded leaf count

The leaves array must contain more than 2 elements. For single or dual fills, use forSingleFill instead.

Example:

const secrets = ["0x1234...", "0x5678...", "0x9abc..."]
const leaves = HashLock.getMerkleLeaves(secrets)
const hashLock = HashLock.forMultipleFills(leaves)

hashSecret

Hash a secret using keccak256.

HashLock.hashSecret(secret: string): string

secret · string · required

32-byte hex-encoded secret value

Returns: Keccak256 hash of the secret

getMerkleLeaves

Convert secrets to Merkle leaves by hashing and indexing them.

HashLock.getMerkleLeaves(secrets: string[]): MerkleLeaf[]

secrets · string[] · required

Array of 32-byte hex-encoded secrets

Returns: Array of Merkle leaves, each computed as keccak256(index, hashSecret(secret))

getMerkleLeavesFromSecretHashes

Convert pre-hashed secrets to Merkle leaves.

HashLock.getMerkleLeavesFromSecretHashes(secretHashes: string[]): MerkleLeaf[]

secretHashes · string[] · required

Array of already-hashed secrets

Returns: Array of Merkle leaves, each computed as keccak256(index, secretHash)

getProof

Generate a Merkle proof for a specific leaf index.

HashLock.getProof(leaves: string[], idx: number): MerkleLeaf[]

leaves · string[] · required

Array of Merkle leaves

idx · number · required

Index of the leaf to prove

Returns: Merkle proof path for the specified leaf

Example:

const leaves = HashLock.getMerkleLeaves(secrets)
const proof = HashLock.getProof(leaves, 0) // Proof for first secret

fromString

Create a HashLock from a hex string.

HashLock.fromString(value: string): HashLock

value · string · required

32-byte hex-encoded hash value

fromBuffer

Create a HashLock from a Buffer.

HashLock.fromBuffer(value: Buffer): HashLock

value · Buffer · required

Buffer containing 32 bytes of hash data

Instance Methods

getPartsCount

Get the number of parts (fills) for a multiple-fill order.

getPartsCount(): bigint

Returns: Number of fills encoded in the hash lock

Only use this method for multiple-fill orders. For single-fill orders, this will return garbage data.

toString

Convert hash lock to hex string.

toString(): string

toBuffer

Convert hash lock to Buffer.

toBuffer(): Buffer

eq

Check if this hash lock equals another.

eq(other: HashLock): boolean

other · HashLock · required

HashLock to compare with

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MerkleLeaf

Type alias for Merkle tree leaves.

type MerkleLeaf = string & {_tag: 'MerkleLeaf'}

A branded string type representing a leaf in a Merkle tree.