@flow-state-dev/next

Platform-agnostic Next.js App Router adapter for flow-state-dev.

Installation

pnpm add @flow-state-dev/next

createNextHandler mounts a FlowState (from createFlowState) onto a catch-all route. It resolves the runtime lazily on the first request and awaits Next.js 15's async params. There's no Vercel-specific behavior here, so the same handler works on Next-on-Cloudflare and other non-Vercel Next deployments.

// app/api/flows/[...path]/route.ts
import { flowstate } from "@/flowstate";
import { createNextHandler } from "@flow-state-dev/next";

export const { GET, POST, PATCH, DELETE } = createNextHandler(flowstate);
export const runtime = "nodejs";
export const dynamic = "force-dynamic";

Deploying to Vercel? Use @flow-state-dev/vercel/next's createVercelNextHandler instead — it adds SSE header shaping and keeps the serverless function alive for background work via waitUntil.

Requires Next.js 15 or later (for the stable async params contract).

See the Engine setup guide for the full createFlowState reference.