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Merkle Tools

Merkle Tools is a JavaScript library for adding data as tree leaves, building Merkle trees, retrieving roots, generating proofs for individual leaves, and validating those proofs against a root. It is distributed as an npm package and licensed under Apache-2.0.

Explore the practical guide ↓

Independent OpenViST project profile, based on linked sources.

Merkle Tools — OpenViST project profile in Developer Tools.
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Understand the project

Practical overview

When it fits

Use it when a JavaScript application needs to construct a Merkle tree and create or check an inclusion proof for one of its leaves.

Who it is for

  • JavaScript developers implementing Merkle-tree data structures or proof workflows.
  • Blockchain developers who need Merkle roots and leaf proofs in application code.
  • Developers who need to validate a proof against a known target hash and root.

Documented uses

  • Add one or more values as Merkle-tree leaves, optionally hashing input values first.
  • Build a tree and retrieve its root.
  • Generate a proof for a leaf by index.
  • Check whether a proof connects a target hash to a Merkle root.
Before you choose

Requirements & limits

The repository provides npm installation instructions and identifies the project as Apache-2.0 licensed.

  • The default hash type is SHA-256; the README also lists SHA, SHA3, and other crypto hash algorithms.
  • Leaves must be Buffers or hexadecimal strings unless the optional doHash setting is used to hash other values.
  • The standard makeTree() behavior promotes a lone leaf node to the next level.
  • The separate makeBTCTree() method is described as reproducing a flawed Bitcoin Merkle-tree implementation and is intended only when that behavior must be replicated.

Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.

Source-based practical guide

Install Merkle Tools and prepare a tree

Add the npm package to a JavaScript project, create a MerkleTools instance, add leaves, and build a tree.

Before you start

  • A JavaScript project using npm.
  • Leaves supplied as Buffers or hexadecimal strings, or other values with the doHash option enabled.

Steps

  1. Install the package with the command below.

    Documented command
    npm install --save merkle-tools

  2. Load it with var MerkleTools = require('merkle-tools') and create an instance; the default hash type is SHA-256.

  3. Add individual leaves or an array of leaves, enabling doHash for values that are not Buffers or hexadecimal strings.

  4. Call makeTree() to build the tree.

Expected outcome

The instance has a built tree and can provide its Merkle root and leaf proofs.

Guide limitations

  • The documented workflow uses JavaScript and npm.
  • Adding leaves or resetting the tree makes it not ready until it is built again.
Documentation 1 ↗
Source-based practical guide

Generate and validate a leaf proof

Retrieve a proof for a leaf in a built tree and check whether it connects a target hash to a Merkle root.

Before you start

  • A MerkleTools instance with leaves added and the tree built.
  • A target hash and Merkle root represented as Buffers or hexadecimal strings for validation.

Steps

  1. Build the tree with makeTree().

  2. Call getProof(index) for the leaf's index.

  3. Pass the proof, target hash, and Merkle root to validateProof(proof, targetHash, merkleRoot).

Expected outcome

Validation returns a boolean indicating whether the proof connects the target hash to the supplied root.

Guide limitations

  • The tree must be ready and the requested leaf index must exist; otherwise getProof returns null.
  • For Bitcoin-style double hashing, the matching double-hash setting must be used during tree construction and proof validation.
Documentation 1 ↗
Evidence and transparency

Sources & review

Official repository ↗
Source record details
Source availability
Active
Sources checked
16 October 2026
Original website title
Tierion/merkle-tools · Official homepage title · retained in its source language
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