SWR recipes

All recipes

Use shared subscriptions in a React app with SWR.

Open recipe

GraphQL over WebSocket · Astro · React

Before you start

Start with an existing Astro · React app. Keep its renderer, routes and plugins. These files add one live view; Spinetab does not create your API.

Your schema exposes Subscription.queue: Queue! with Queue.open: Int!. Each event contains the complete queue value. Serve the graphql-transport-ws protocol at /graphql. Queries and mutations, if used, go to /graphql. This is a GraphQL endpoint, not a plain SSE or WebSocket feed.

The examples use same-origin URLs and declare anonymous: true: no token is supplied, although cookies still flow. For a separate API origin, use its URL and configure CORS or your application's proxy. For private data, add credentials and user scopes; never put a secret in these files.

1. Install

pnpm add spinetab graphql@^17.0.2 graphql-ws@^6.3.0 swr@^2.5.1

Keep your framework's existing dependencies. See compatible versions if upgrading an older app.

2. Configure your app

Merge this addition into your configuration; preserve existing plugins and options. Restart the dev server afterwards. The plugin bundles the worker and discovers the adapters imported below.

astro.config.mjs

import react from "@astrojs/react";
import { defineConfig } from "astro/config";
import { spinetab } from "spinetab/astro";

export default defineConfig({ integrations: [react(), spinetab()] });

3. Connect and render

Save these files together in src/components/recipe/.

SWR uses its default cache. The constant queue key always returns the same source; if the endpoint varies, derive it from that key. With SWR 2.5.1 and React 19.3, avoid nesting a custom cache provider inside StrictMode; see the upstream restriction.

reconcile: "latest" fits this full-state contract: the next complete event restores the displayed value after a gap. Use a refresh/merge policy for deltas or partial GraphQL results. Reconnecting alone does not reconstruct missed state.

src/components/recipe/live.ts

import { createSpinetab } from "spinetab";

export const spinetab = createSpinetab({ anonymous: true });

src/components/recipe/queue-types.ts

export type Queue = { open: number };
export type QueueView = { open?: number; problem?: string };

src/components/recipe/source.ts

import { parse } from "graphql";
import {
  type GraphqlDocument,
  type GraphqlResult,
  graphqlWs,
} from "spinetab/graphql-ws";
import type { Queue, QueueView } from "./queue-types";

const document: GraphqlDocument<
  { queue: Queue },
  Record<string, never>
> = parse("subscription Queue { queue { open } }");

export const queueSource = graphqlWs("/graphql").subscription({
  query: document,
});

export function selectQueue(
  result: GraphqlResult<{ queue: Queue }>,
): QueueView {
  return {
    open: result.data?.queue?.open,
    problem:
      result.errors?.map((error) => error.message).join("; ") ||
      (result.data?.queue ? undefined : "The server returned no queue."),
  };
}

src/components/recipe/Recipe.tsx

import { swrSubscription } from "spinetab/swr";
import useSWRSubscription from "swr/subscription";
import { spinetab } from "./live";
import { queueSource, selectQueue } from "./source";

const subscribe = swrSubscription(spinetab, (_key: "queue") => queueSource, {
  map: selectQueue,
  reconcile: "latest",
});

export default function Recipe() {
  const { data, error } = useSWRSubscription("queue", subscribe);
  if (error || data?.problem)
    return <p role="alert">{error?.message ?? data?.problem}</p>;
  if (data?.open === undefined) return <p role="status">Loading queue…</p>;
  return (
    <p>
      <output>{data.open}</output> open
    </p>
  );
}

4. Mount the view

src/pages/queue.astro

---
import Recipe from "../components/recipe/Recipe";
---

<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Live queue</title>
  </head>
  <body>
    <Recipe client:load />
  </body>
</html>

Provider and consumer live in this one hydrated island. client:load starts it on page load; client:visible defers it until visible. Without hydration no subscription starts.

Check the result

Open /queue in two tabs of the same browser profile. Both should show advancing queue values. Matching subscriptions share upstream work when SharedWorker is available; fallback runs independently in each tab. Remove one view and the other should keep updating. Removing the last view releases its subscription; connection closure can follow the adapter's idle delay.

API options and advanced recovery · Authentication