@no-witness-labs/hydra-sdk

TypeScript SDK for the Cardano Hydra Head protocol. Manage head lifecycle, subscribe to events, and build L2 transactions with a type-safe API.

Installation

pnpm add @no-witness-labs/hydra-sdk

Quick Start

import { Head } from "@no-witness-labs/hydra-sdk";

const head = await Head.create({ url: "ws://localhost:4001" });

head.subscribe((event) => {
  console.log(`[${event.tag}]`, event.payload);
});

await head.init();
await head.commit({});
await head.close();
await head.fanout();
await head.dispose();

Features

• Head lifecycle — Init, Commit, Close, Contest, Fanout, Abort, SafeClose
• L2 transactions — NewTx, Decommit, Recover (incremental commits)
• Event subscriptions — Callback, async iterator, and Effect stream APIs
• WebSocket transport — Auto-reconnect with exponential backoff and heartbeat monitoring
• HydraProvider — Drop-in Provider for evolution-sdk transaction building on L2
• Effect integration — Every operation available as an Effect for composability
• Cross-platform — Works in Node.js and all major browsers (Chrome, Firefox, Safari)

Documentation

Full documentation at no-witness-labs.github.io/hydra-sdk.

License

MIT