SDK overview

Complete reference for PolynomialHQ's browser, React, server, and protocol packages.

SDKs

@polynomialhq/react

Providers and hooks for collaborative React interfaces. Start here.

@polynomialhq/client

Framework-agnostic rooms, presence, events, storage, and the connection layer.

@polynomialhq/server

Room tokens, identity tokens, room management, and server-side broadcasts.

@polynomialhq/contracts

Zod schemas and codecs for the versioned WebSocket protocol.

Package	Primary entry point	Runtime
`@polynomialhq/client`	`createClient()`	Browser, or a runtime with `WebSocket` and `fetch`
`@polynomialhq/react`	`PolynomialProvider`	Browser, React 18.2+
`@polynomialhq/server`	`new PolynomialServer()`	Node.js only — uses `node:crypto`
`@polynomialhq/contracts`	`clientWebSocketMessageSchema`	Anywhere

All packages are ESM, include TypeScript declarations, and publish a single root export.

@polynomialhq/react depends on @polynomialhq/client, which depends on @polynomialhq/contracts. Installing the React package brings the whole browser stack, and it re-exports createClient so most applications never import the client package by name.

@polynomialhq/server is independent: it shares no code with the browser packages and speaks HTTP plus token signing rather than the WebSocket protocol.

Which layer should I use?

Start with @polynomialhq/react for a React interface.
Use @polynomialhq/client for another view framework, a state adapter, or direct room access.
Use @polynomialhq/server for every operation involving a sk_... secret.
Use @polynomialhq/contracts only when implementing a protocol adapter, worker, or raw WebSocket integration.