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Postgres.js

Postgres.js ↗ is a modern, fully-featured PostgreSQL driver for Node.js. This example demonstrates how to use Postgres.js with Cloudflare Hyperdrive in a Workers application.

Install Postgres.js ↗:

Terminal window
npm i postgres@>3.4.5

Add the required Node.js compatibility flags and Hyperdrive binding to your wrangler.jsonc file:

{
  "$schema": "./node_modules/wrangler/config-schema.json",
  "compatibility_flags": [
    "nodejs_compat"
  ],
  "compatibility_date": "2024-09-23",
  "hyperdrive": [
    {
      "binding": "HYPERDRIVE",
      "id": "<your-hyperdrive-id-here>"
    }
  ]
}

Create a Worker that connects to your PostgreSQL database via Hyperdrive:

TypeScript
// filepath: src/index.ts
import postgres from "postgres";


export default {
  async fetch(
    request: Request,
    env: Env,
    ctx: ExecutionContext,
  ): Promise<Response> {
    // Create a database client that connects to your database via Hyperdrive
    // using the Hyperdrive credentials
    const sql = postgres(env.HYPERDRIVE.connectionString, {
      // Limit the connections for the Worker request to 5 due to Workers' limits on concurrent external connections
      max: 5,
      // If you are not using array types in your Postgres schema, disable `fetch_types` to avoid an additional round-trip (unnecessary latency)
      fetch_types: false,


      // This is set to true by default, but certain query generators such as Kysely or queries using sql.unsafe() will set this to false. Hyperdrive will not cache prepared statements when this option is set to false and will require additional round-trips.
      prepare: true,
    });


    try {
      // A very simple test query
      const result = await sql`select * from pg_tables`;


      // Return result rows as JSON
      return Response.json({ success: true, result: result });
    } catch (e: any) {
      console.error("Database error:", e.message);


      return Response.error();
    }
  },
} satisfies ExportedHandler<Env>;