@rsc-boundary/core

Framework-agnostic core of RSC Boundary.

This package contains the React fiber walking engine, highlight overlay, devtools UI components (pill, panel), and the FrameworkAdapter contract. It has no dependency on Next.js or TanStack Start.

You do not need to install this package directly. Install the adapter for your framework instead:

• @rsc-boundary/next — Next.js App Router
• @rsc-boundary/start — TanStack Start

Building a custom adapter

If you want to support a different RSC framework, implement FrameworkAdapter and use createRscBoundaryProvider:

import type { FrameworkAdapter } from "@rsc-boundary/core";

export const myAdapter: FrameworkAdapter = {
  name: "my-framework",
  internals: new Set(["RouterProvider", "InternalComponent", /* ... */]),
  rootCandidates: () => [
    document.getElementById("app"),
    document.body,
    document.documentElement,
  ],
  resolveScanContainer: () =>
    document.getElementById("app") ?? document.body,
};

// devtools.tsx  ("use client")
import { RscDevtools } from "@rsc-boundary/core";
import { myAdapter } from "./adapter";

export function RscDevtoolsMyFramework() {
  return <RscDevtools adapter={myAdapter} />;
}

// provider.tsx  (no "use client" — server component)
import { createRscBoundaryProvider } from "@rsc-boundary/core";
import { RscDevtoolsMyFramework } from "./devtools";

export const RscBoundaryProvider = createRscBoundaryProvider(RscDevtoolsMyFramework);

API

| Export | Description | |---|---| | createRscBoundaryProvider(DevtoolsComponent) | Factory that returns a server component provider | | RscDevtools | Client component; accepts adapter prop | | RscServerBoundaryMarker | Optional server component for explicit region labeling | | FrameworkAdapter | Interface adapter objects must implement | | SERVER_BOUNDARY_DATA_ATTR | Data attribute used by RscServerBoundaryMarker |

Requirements

• React 19+
• react-dom 19+