Installation

Packages

flow-state.dev is distributed as separate packages. Install what you need:

# Core (required) — block builders, flow definitions, types
pnpm add @flow-state-dev/core zod

# Server — action runtime, stores, SSE streaming
pnpm add @flow-state-dev/server

# Client — HTTP/SSE transport (no React dependency)
pnpm add @flow-state-dev/client

# React — hooks, renderers, context providers
pnpm add @flow-state-dev/react

# Testing — test harnesses for blocks and flows
pnpm add -D @flow-state-dev/testing

Which packages do I need?

Use case	Packages
Define flows only (shared library)	core
Server-side execution	core + server
Client-side consumption	core + client
Full-stack React app	core + server + react
Testing	core + testing

The react package depends on client internally — you don't need to install client separately when using react.

Peer Dependencies

• zod ^3.24.1 — Used for schema validation across all packages
• react ^18.0.0 || ^19.0.0 — Required only by @flow-state-dev/react

TypeScript

flow-state.dev is written in TypeScript and ships type definitions. For best results:

• TypeScript ^5.7
• Enable strict mode in your tsconfig.json

Server Framework Compatibility

The server package exposes standard request handlers. The createFlowApiRouter returns handlers compatible with:

• Next.js App Router (catch-all route)
• Any framework supporting standard Request/Response objects

Next.js App Router

// app/api/flows/[...path]/route.ts
const router = createFlowApiRouter({ registry });
export const GET = router.GET;
export const POST = router.POST;
export const DELETE = router.DELETE;