InterchainJS

A single, universal signing interface for any network. Birthed from the interchain ecosystem for builders. Create adapters for any Web3 network.

Table of Contents

• Introduction
• Overview
• Installation
• Quick Start
  • Create Interchain App
• Supported Networks
  • Cosmos Network
  • Injective Network
  • Ethereum Network
• Interchain JavaScript Stack ⚛️
• Credits
• Disclaimer

InterchainJS: Universal Signing for Web3

InterchainJS (opens in a new tab) is a universal signing interface designed for seamless interoperability across blockchain networks. It is one of the core libraries of the Interchain JavaScript Stack (opens in a new tab), a modular framework that brings Web3 development to millions of JavaScript developers.

At its core, InterchainJS provides a flexible adapter pattern that abstracts away blockchain signing complexities, making it easy to integrate new networks, manage accounts, and support diverse authentication protocols and signing algorithms—all in a unified, extensible framework.

Overview

InterchainJS sits at the foundation of the Interchain JavaScript Stack (opens in a new tab), a set of tools that work together like nested building blocks:

• InterchainJS (opens in a new tab) → Powers signing across Cosmos, Ethereum (EIP-712), and beyond.
• Interchain Kit (opens in a new tab) → Wallet adapters that connect dApps to multiple blockchain networks.
• Interchain UI (opens in a new tab) → A flexible UI component library for seamless app design.
• Create Interchain App (opens in a new tab) → A developer-friendly starter kit for cross-chain applications.

This modular architecture ensures compatibility, extensibility, and ease of use, allowing developers to compose powerful blockchain applications without deep protocol-specific knowledge.

Visualizing InterchainJS Components

The diagram below illustrates how InterchainJS connects different signer types to various network classes, showcasing its adaptability for a wide range of blockchain environments.

Installation

This guide will walk you through the process of installing and setting up interchainjs for your project.

You can install interchainjs using Yarn:

yarn add interchainjs
yarn add @interchainjs/cosmos

or npm

npm i interchainjs
npm i @interchainjs/cosmos

Quick Start

Using Signers Directly

Create and use signers for transaction signing and broadcasting:

import { DirectSigner } from '@interchainjs/cosmos';
import { Secp256k1HDWallet } from '@interchainjs/cosmos';
import { HDPath } from '@interchainjs/types';
 
// Create wallet from mnemonic
const wallet = await Secp256k1HDWallet.fromMnemonic(
  "your twelve word mnemonic phrase here",
  {
    derivations: [{
      prefix: "cosmos",
      hdPath: HDPath.cosmos(0, 0, 0).toString(), // m/44'/118'/0'/0/0
    }]
  }
);
 
// Create signer
const signer = new DirectSigner(wallet, {
  chainId: 'cosmoshub-4',
  queryClient: queryClient,
  addressPrefix: 'cosmos'
});
 
// Sign and broadcast transaction
const result = await signer.signAndBroadcast({
  messages: [{
    typeUrl: '/cosmos.bank.v1beta1.MsgSend',
    value: {
      fromAddress: 'cosmos1...',
      toAddress: 'cosmos1...',
      amount: [{ denom: 'uatom', amount: '1000000' }]
    }
  }],
  fee: {
    amount: [{ denom: 'uatom', amount: '5000' }],
    gas: '200000'
  },
  memo: 'Transfer via InterchainJS'
});
 
console.log('Transaction hash:', result.transactionHash);

Using with External Wallets

For integration with browser wallets like Keplr:

import { DirectSigner } from '@interchainjs/cosmos';
 
// Get offline signer from Keplr
await window.keplr.enable(chainId);
const offlineSigner = window.keplr.getOfflineSigner(chainId);
 
// Create signer with offline signer
const signer = new DirectSigner(offlineSigner, {
  chainId: 'cosmoshub-4',
  queryClient: queryClient,
  addressPrefix: 'cosmos'
});
 
// Use the same signing interface
const result = await signer.signAndBroadcast({
  messages: [/* your messages */],
  fee: { amount: [{ denom: 'uatom', amount: '5000' }], gas: '200000' }
});

Quick Setup with create-interchain-app

The easiest way to get started is by using the create-interchain-app tool, which sets up a complete project with all necessary dependencies:

npm install -g create-interchain-app
 
cia --example authz

Then an authz example website will be created and users can take a look how signing clients and helper functions are used.

Supported Networks

Cosmos Network

Injective Network

Ethereum Network

Developer Documentation

For Contributors and Network Implementers

• Network Implementation Guide - Comprehensive guide for implementing new blockchain network support
• Workflow Builder and Plugins Guide - Plugin-based transaction workflow architecture
• Auth vs. Wallet vs. Signer - Understanding the three-layer architecture
• Tutorial - Using and extending signers in the InterchainJS ecosystem

Architecture and Design

InterchainJS follows a modular, three-layer architecture that separates concerns and enables flexible blockchain integration:

1. Auth Layer: Cryptographic operations and key management
2. Wallet Layer: Account management and address derivation
3. Signer Layer: Transaction building, signing, and broadcasting

This separation allows for maximum flexibility while maintaining type safety and consistent interfaces across different blockchain networks.

Interchain JavaScript Stack ⚛️

A unified toolkit for building applications and smart contracts in the Interchain ecosystem

Credits

🛠 Built by Hyperweb (formerly Cosmology) — if you like our tools, please checkout and contribute to our github ⚛️ (opens in a new tab)

Disclaimer

AS DESCRIBED IN THE LICENSES, THE SOFTWARE IS PROVIDED "AS IS", AT YOUR OWN RISK, AND WITHOUT WARRANTIES OF ANY KIND.

No developer or entity involved in creating this software will be liable for any claims or damages whatsoever associated with your use, inability to use, or your interaction with other users of the code, including any direct, indirect, incidental, special, exemplary, punitive or consequential damages, or loss of profits, cryptocurrencies, tokens, or anything else of value.