Getting Started

Introduction

What Hydra SDK is, how its packages fit together, and what you need to get started.

Hydra SDK is a TypeScript toolkit for building Cardano wallet applications with Hydra Layer 2 integration. It wraps the cardano-serialization-lib WASM bindings and the Hydra Head protocol behind a modular, type-safe API — delivering native-level performance in the browser while staying compatible with modern build tools like Vite and Rollup.

Why Hydra SDK?

WASM-powered — the core runs on cardano-serialization-lib compiled to WebAssembly, up to 10× faster than JavaScript-based SDKs.
Zero bundle issues — no polyfills for util, stream, or crypto. Works out of the box with Vite, Rollup, Nuxt 3, React + Vite, and Next.js.
Browser-first — designed for DApps, with an environment-aware WASM loader that also runs on Node.js.
Modular — install only the packages you need; each ships ESM + CJS.
Type-safe — comprehensive TypeScript definitions across every namespace and builder.

Looking for the latest release notes? See the Changelog.

Prerequisites

Before you begin, make sure you have:

Node.js 18.20.0 or higher
A package manager — npm, pnpm, or yarn
Basic TypeScript / JavaScript knowledge
Familiarity with core Cardano concepts (addresses, UTxOs, transactions)

Architecture

The SDK is a monorepo of four packages that build on each other:

Package	Responsibility
`@hydra-sdk/core`	HD wallet creation & management, UTxO types, Cardano utilities
`@hydra-sdk/bridge`	Hydra Head lifecycle over WebSocket + REST
`@hydra-sdk/transaction`	Low-level TxBuilder for Layer 1 and Hydra
`@hydra-sdk/cardano-wasm`	Environment-aware WASM bindings

graph LR
    A[Your App] --> B[core]
    A --> C[bridge]
    A --> D[transaction]

    B --> E[cardano-wasm]
    C --> B
    C --> E
    D --> B
    D --> E

All packages import Cardano primitives through @hydra-sdk/cardano-wasm — never import @emurgo/cardano-serialization-lib directly.