Building Data Apps using Cloudflare Workers, and Notion Dabatases

Cloudflare Workers execute at the edge — code runs in the region nearest to the request, not in a fixed data center. P90 latency is typically under 100ms. Notion databases give non-technical operators a UI to manage records while exposing the same data over a REST API. Together they form a data app stack you can ship in an afternoon and scale without ops overhead.

The stack

Querying the database

Every row in a Notion database is a page. The /databases/:id/query endpoint returns an array of page objects, each with a properties field keyed by column name.

// src/notion.js
export async function queryDatabase(dbId, token, filter = {}) {
  const res = await fetch(`https://api.notion.com/v1/databases/${dbId}/query`, {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${token}`,
      'Notion-Version': '2022-06-28',
      'Content-Type': 'application/json',
    },
    body: JSON.stringify(filter),
  });
  return res.json();
}

Property shapes vary by type. Title, rich text, and checkbox each have a different structure. Extract explicitly — don't assume shape.

function extractTitle(page) {
  return page.properties.Name?.title[0]?.plain_text ?? '';
}

function extractPublished(page) {
  return page.properties.published?.checkbox ?? false;
}

Caching with KV

Notion's free plan enforces a 3 req/s rate limit across your integration. Cache every query result in KV. A TTL of 300 seconds absorbs traffic spikes without serving stale data for long.

async function getCached(key, fetcher, env, ttl = 300) {
  const cached = await env.KV.get(key);
  if (cached) return JSON.parse(cached);

  const data = await fetcher();
  await env.KV.put(key, JSON.stringify(data), { expirationTtl: ttl });
  return data;
}

Bust the cache on write by deleting the key:

await env.KV.delete('index');

Routing

A minimal Worker that serves a Notion-backed JSON API:

// src/index.js
export default {
  async fetch(request, env) {
    const url = new URL(request.url);

    if (url.pathname === '/api/articles') {
      const data = await getCached(
        'index',
        () => queryDatabase(env.NOTION_DB_ID, env.NOTION_TOKEN),
        env
      );
      return Response.json(data);
    }

    return new Response('Not found', { status: 404 });
  }
};

Set NOTION_TOKEN as a secret, never in wrangler.toml. Set NOTION_DB_ID as a plain var — it's not sensitive.

# wrangler.toml
[vars]
NOTION_DB_ID = "your-db-id-here"

[[kv_namespaces]]
binding = "KV"
id = "your-kv-namespace-id"

When to use this

This stack fits content-heavy apps with a flat or lightly relational data model — articles, products, tasks, events. It suits teams where a non-engineer needs to own the data, and where you don't want to operate a database.

Don't use it for write-heavy workloads, relational joins, high-cardinality queries, or any case where you need transactional guarantees. Notion is a CMS, not a relational database. Treat it accordingly.