cloudflare-hyperdrive

Cloudflare Hyperdrive

Rules

1. Create a new database client/connection inside each Worker invocation (fetch, queue, scheduled, or Durable Object method); never create global clients or driver pools (new Pool(), createPool()). Hyperdrive manages the shared origin pool.
2. Use the Hyperdrive binding directly: Postgres uses env.HYPERDRIVE.connectionString
3. Let Hyperdrive manage connection lifecycle: keep transactions short, avoid long-lived pinned connections, and do not call client.end() / connection.end() for routine per-request cleanup.

Example 1: PostgreSQL (Hyperdrive handles pooling)

import { Client } from "pg";

export default {
  async fetch(_request, env): Promise<Response> {
    const client = new Client({
      connectionString: env.HYPERDRIVE.connectionString,
    });

    await client.connect();
    const result = await client.query("SELECT NOW() AS now");
    return Response.json(result.rows[0]);
  },
} satisfies ExportedHandler<{ HYPERDRIVE: Hyperdrive }>;