Hyperdrive

Accelerate access to existing PostgreSQL and MySQL databases with connection pooling and caching.

FIRST: Create Hyperdrive Configuration

# Create a Hyperdrive configuration for your database
npx wrangler hyperdrive create <YOUR_CONFIG_NAME> --connection-string="postgres://user:password@HOSTNAME_OR_IP_ADDRESS:PORT/database_name"

# Copy the ID from the output for your wrangler.jsonc

Add the binding to wrangler.jsonc:

{
  "hyperdrive": [
    {
      "binding": "HYPERDRIVE",
      "id": "<YOUR_DATABASE_ID>"
    }
  ]
}

When to Use

Use Hyperdrive when:

• Connecting to existing databases – PostgreSQL or MySQL hosted anywhere
• Reducing connection latency – Connection pooling eliminates per-request connection overhead
• Geographic distribution – Cache query results at the edge for read-heavy workloads
• Database migration – Connect Workers to traditional databases without rewriting apps
• Connection limits – Share connections across many Workers efficiently

Quick Reference

Connect with Postgres.js

Install dependencies first:

npm install postgres

Code:

import postgres from "postgres";

export interface Env {
  // If you set another name in the Wrangler config file as the value for 'binding',
  // replace "HYPERDRIVE" with the variable name you defined.
  HYPERDRIVE: Hyperdrive;
}

export default {
  async fetch(request, env, ctx): Promise<Response> {
    // Create a database client that connects to your database via Hyperdrive.
    //
    // Hyperdrive generates a unique connection string you can pass to
    // supported drivers, including node-postgres, Postgres.js, and the many
    // ORMs and query builders that use these drivers.
    const sql = postgres(env.HYPERDRIVE.connectionString);

    try {
      // Test query
      const results = await sql`SELECT * FROM pg_tables`;

      // Return result rows as JSON
      return Response.json(results);
    } catch (e) {
      console.error(e);
      return Response.json(
        { error: e instanceof Error ? e.message : e },
        { status: 500 },
      );
    }
  },
} satisfies ExportedHandler<Env>;

Connection Management

Important: Do NOT call sql.end() or close connections manually.

• Hyperdrive manages connection pooling automatically
• Connections are reused across requests efficiently
• Closing connections can cause errors and reduce performance
• The connection pool persists between Worker invocations

// ❌ DON'T DO THIS
const sql = postgres(env.HYPERDRIVE.connectionString);
await sql`SELECT * FROM users`;
await sql.end(); // DON'T close the connection

// ✅ DO THIS INSTEAD
const sql = postgres(env.HYPERDRIVE.connectionString);
await sql`SELECT * FROM users`;
// Let Hyperdrive manage the connection

Supported Drivers

See references/drivers.md for detailed driver integration examples.

ORM Integration

Drizzle ORM

import { drizzle } from 'drizzle-orm/postgres-js';
import postgres from 'postgres';

export default {
  async fetch(request, env, ctx): Promise<Response> {
    const client = postgres(env.HYPERDRIVE.connectionString);
    const db = drizzle(client);
    
    const results = await db.select().from(users);
    return Response.json(results);
  }
};

Prisma

Important: Add ?connection_limit=1 to prevent connection pool exhaustion:

import { PrismaClient } from '@prisma/client';

export default {
  async fetch(request, env, ctx): Promise<Response> {
    // Append connection_limit=1 for Prisma
    const prisma = new PrismaClient({
      datasourceUrl: env.HYPERDRIVE.connectionString + '?connection_limit=1'
    });
    
    const users = await prisma.user.findMany();
    return Response.json(users);
  }
};

MySQL Support

Hyperdrive also supports MySQL databases:

# Create MySQL Hyperdrive config
npx wrangler hyperdrive create my-mysql \
  --connection-string="mysql://user:password@host:3306/database"

import { connect } from '@planetscale/database';

export default {
  async fetch(request, env, ctx): Promise<Response> {
    const conn = connect({ url: env.HYPERDRIVE.connectionString });
    const results = await conn.execute('SELECT * FROM users');
    return Response.json(results.rows);
  }
};

Caching Configuration

Hyperdrive automatically caches query results. Configure caching behavior when creating the config:

# Default: cache enabled with 60s TTL
npx wrangler hyperdrive create my-db \
  --connection-string="postgres://..." \
  --caching-disabled=false \
  --max-age=60

Caching behavior:

• Only read queries (SELECT) are cached
• Write queries (INSERT, UPDATE, DELETE) are never cached
• Cache is automatically invalidated when writes occur to the same table

Detailed References

• references/setup.md – Creating configs, connection strings, security
• references/drivers.md – Driver-specific patterns, ORMs, troubleshooting
• references/testing.md – Local PostgreSQL setup, Vitest integration, testing with real databases

Best Practices

1. Use Postgres.js 3.4.5+ – Best compatibility and performance with Hyperdrive
2. Never call sql.end() – Hyperdrive manages connection lifecycle
3. One config per database – Reuse the same Hyperdrive binding across Workers
4. Use Prisma carefully – Always add ?connection_limit=1 to the connection string
5. Test locally with wrangler dev – Use --remote flag to connect through Hyperdrive
6. Store credentials securely – Never commit connection strings; use environment variables
7. Monitor with observability – Enable in wrangler.jsonc to track query performance
8. Connection string format – Use standard Postgres/MySQL connection string format

Troubleshooting

Connection errors:

• Verify your database allows connections from Cloudflare IPs
• Check firewall rules and security groups
• Test connection string format (must be valid Postgres/MySQL URL)

Prisma connection pool errors:

• Add ?connection_limit=1 to the connection string
• Ensure Prisma client is initialized once per request, not globally

“Too many connections” errors:

• Your origin database may have reached its connection limit
• Increase max connections on your database server
• Hyperdrive already pools connections efficiently

Local development:

# Use --remote to test with actual Hyperdrive
npx wrangler dev --remote

# Or use local connection string for development
# (add to .dev.vars)
HYPERDRIVE_CONNECTION_STRING=postgres://localhost:5432/mydb