
## Bridging Ethereum and Cosmos with Universal JavaScript Signing

In the spirit of our mission to unify cross-chain ecosystems through JavaScript, we're excited to announce a major milestone for the Interchain JavaScript Stack: **Ethereum signing support in InterchainJS**.

With this update, developers can now sign Ethereum transactions using the **same familiar APIs** they use for Cosmos-based chains.

No more context switching. No more juggling multiple libraries. Just one universal signing toolkit—powered by JavaScript.

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## Why It Matters

Web3 development has long been fragmented:

- Cosmos developers use **CosmJS** (and soon, [**InterchainJS**](https://github.com/hyperweb-io/interchainjs))
- Ethereum developers rely on [**ethers.js**](https://github.com/ethers-io/ethers.js) or [**wagmi**](https://github.com/wevm/wagmi)

Building cross-chain dApps meant gluing together incompatible signing libraries, navigating different encoding schemes, and switching mental models constantly. It slows innovation and raises the barrier to entry.

**Now, with one cohesive library that plugs directly into the interchain, you can:**

- Interact with both Cosmos and Ethereum (and other supported chains)
- Universal transaction signing with one clean, consistent codebase.
- Plug in wallet adapters like **Metamask**, **Keplr**, or **Ledger** with minimal configuration
- Implement standards like **EIP-712**, Amino, and Protobuf seamlessly through one universal engine

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## The InterchainJS Difference

InterchainJS is inspired by CosmJS but redesigned from the ground up for multichain flexibility:

- **Adapter Pattern** – Easily plug in new chains and wallets
- **Universal Signing Engine** – One API to handle Ethereum's EIP-712 and Cosmos's Amino/Protobuf
- **Performance Focus** – Modular, tree-shakable, and built for frontend performance
- **Extensible Architecture** – Add support for new formats and chains with minimal effort

> "This is like having ethers.js and cosmjs in one, with a better DX. It's your universal remote for chain interaction." — _Dan Lynch, founder of Hyperweb_

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## How It Works

Under the hood, InterchainJS uses a dynamic adapter system to route signing requests:

- Automatically detects chain context (e.g., Cosmos vs. Ethereum)
- Applies the correct encoding, key derivation, and transport logic

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## What's Next?

We're just getting started.

Coming soon: support for Solana and Bitcoin, all supported through the same InterchainJS interface.

With the Hyperweb Virtual Machine (HVM) and our full-stack TypeScript platform, we're creating a future where multichain dApps are as easy to build as web apps—**fast, modular, and developer-first**.

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## Get Started

Ready to get started? Choose your path:

- 🔐 Signing tutorial: [Step-by-step guide to Ethereum signing with InterchainJS](/learn/interchainjs/ethereum-signing-with-interchainjs)
- 🏗️ Quick start: [Scaffold an EVM project with Create Interchain App](/learn/interchainjs/ethereum-quick-start-with-interchainjs)


InterchainJS now supports Ethereum signing—build multichain apps for Ethereum and Cosmos with one JavaScript API. Simpler, unified Web3 development.

Ethereum Signing Comes to InterchainJS