gh-jezweb-claude-skills-skills-cloudflare-hyperdrive/SKILL.md

name, description, license

name	description	license
cloudflare-hyperdrive	Connect Workers to PostgreSQL/MySQL with Hyperdrive's global pooling and caching. Use when: connecting to existing databases, setting up connection pools, using node-postgres/mysql2, integrating Drizzle/Prisma, or troubleshooting pool acquisition failures, TLS errors, nodejs_compat missing, or eval() disallowed.	MIT

Cloudflare Hyperdrive

Status: Production Ready ✅ Last Updated: 2025-11-23 Dependencies: cloudflare-worker-base (recommended for Worker setup) Latest Versions: wrangler@4.50.0, pg@8.16.3+ (minimum), postgres@3.4.7, mysql2@3.15.3

Recent Updates (2025):

• July 2025: Configurable connection counts (min 5, max ~20 Free/~100 Paid)
• May 2025: 5x faster cache hits (regional prepared statement caching), FedRAMP Moderate authorization
• April 2025: Free plan availability (10 configs), MySQL GA support
• March 2025: 90% latency reduction (pools near database), IP access control (standard CF IP ranges)
• nodejs_compat_v2: pg driver no longer requires node_compat mode (auto-enabled with compatibility_date 2024-09-23+)
• Limits: 25 Hyperdrive configurations per account (Paid), 10 per account (Free)

---

Quick Start (5 Minutes)

1. Create Hyperdrive Configuration

# For PostgreSQL
npx wrangler hyperdrive create my-postgres-db \
  --connection-string="postgres://user:password@db-host.cloud:5432/database"

# For MySQL
npx wrangler hyperdrive create my-mysql-db \
  --connection-string="mysql://user:password@db-host.cloud:3306/database"

# Output:
# ✅ Successfully created Hyperdrive configuration
#
# [[hyperdrive]]
# binding = "HYPERDRIVE"
# id = "a76a99bc-7901-48c9-9c15-c4b11b559606"

Save the id value - you'll need it in the next step!

---

2. Configure Bindings in wrangler.jsonc

Add to your wrangler.jsonc:

{
  "name": "my-worker",
  "main": "src/index.ts",
  "compatibility_date": "2024-09-23",
  "compatibility_flags": ["nodejs_compat"],  // REQUIRED for database drivers
  "hyperdrive": [
    {
      "binding": "HYPERDRIVE",                     // Available as env.HYPERDRIVE
      "id": "a76a99bc-7901-48c9-9c15-c4b11b559606"  // From wrangler hyperdrive create
    }
  ]
}

CRITICAL:

• nodejs_compat flag is REQUIRED for all database drivers
• binding is how you access Hyperdrive in code (env.HYPERDRIVE)
• id is the Hyperdrive configuration ID (NOT your database ID)

---

3. Install Database Driver

# For PostgreSQL (choose one)
npm install pg           # node-postgres (most common)
npm install postgres     # postgres.js (modern, minimum v3.4.5)

# For MySQL
npm install mysql2       # mysql2 (minimum v3.13.0)

---

4. Query Your Database

PostgreSQL with node-postgres (pg):

import { Client } from "pg";

type Bindings = {
  HYPERDRIVE: Hyperdrive;
};

export default {
  async fetch(request: Request, env: Bindings, ctx: ExecutionContext) {
    const client = new Client({
      connectionString: env.HYPERDRIVE.connectionString
    });

    await client.connect();

    try {
      const result = await client.query('SELECT * FROM users LIMIT 10');
      return Response.json({ users: result.rows });
    } finally {
      // Clean up connection AFTER response is sent
      ctx.waitUntil(client.end());
    }
  }
};

MySQL with mysql2:

import { createConnection } from "mysql2/promise";

export default {
  async fetch(request: Request, env: Bindings, ctx: ExecutionContext) {
    const connection = await createConnection({
      host: env.HYPERDRIVE.host,
      user: env.HYPERDRIVE.user,
      password: env.HYPERDRIVE.password,
      database: env.HYPERDRIVE.database,
      port: env.HYPERDRIVE.port,
      disableEval: true  // REQUIRED for Workers (eval() not supported)
    });

    try {
      const [rows] = await connection.query('SELECT * FROM users LIMIT 10');
      return Response.json({ users: rows });
    } finally {
      ctx.waitUntil(connection.end());
    }
  }
};

---

5. Deploy

npx wrangler deploy

That's it! Your Worker now connects to your existing database via Hyperdrive with:

• ✅ Global connection pooling
• ✅ Automatic query caching
• ✅ Reduced latency (eliminates 7 round trips)

---

How Hyperdrive Works

Hyperdrive eliminates 7 connection round trips (TCP + TLS + auth) by:

• Edge connection setup near Worker (low latency)
• Connection pooling near database (March 2025: 90% latency reduction)
• Query caching at edge (May 2025: 5x faster cache hits)

Result: Single-region databases feel globally distributed.

---

Setup Steps

Prerequisites

• Cloudflare account with Workers access
• PostgreSQL (v9.0-17.x) or MySQL (v5.7-8.x) database
• Database accessible via public internet (TLS/SSL required) or private network (Cloudflare Tunnel)
• April 2025: Available on Free plan (10 configs) and Paid plan (25 configs)

Connection String Formats

# PostgreSQL
postgres://user:password@host:5432/database
postgres://user:password@host:5432/database?sslmode=require

# MySQL
mysql://user:password@host:3306/database

# URL-encode special chars: p@ssw$rd → p%40ssw%24rd

---

Connection Patterns

Single Connection (pg.Client)

const client = new Client({ connectionString: env.HYPERDRIVE.connectionString });
await client.connect();
const result = await client.query('SELECT ...');
ctx.waitUntil(client.end());  // CRITICAL: Non-blocking cleanup

Use for: Simple queries, single query per request

Connection Pool (pg.Pool)

const pool = new Pool({
  connectionString: env.HYPERDRIVE.connectionString,
  max: 5  // CRITICAL: Workers limit is 6 connections (July 2025: configurable ~20 Free, ~100 Paid)
});
const [result1, result2] = await Promise.all([
  pool.query('SELECT ...'),
  pool.query('SELECT ...')
]);
ctx.waitUntil(pool.end());

Use for: Parallel queries in single request

Connection Cleanup Rule

ALWAYS use ctx.waitUntil(client.end()) - non-blocking cleanup after response sent NEVER use await client.end() - blocks response, adds latency

---

ORM Integration

Drizzle ORM

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

const sql = postgres(env.HYPERDRIVE.connectionString, { max: 5 });
const db = drizzle(sql);
const allUsers = await db.select().from(users);
ctx.waitUntil(sql.end());

Prisma ORM

import { PrismaPg } from "@prisma/adapter-pg";
import { PrismaClient } from "@prisma/client";
import { Pool } from "pg";

const pool = new Pool({ connectionString: env.HYPERDRIVE.connectionString, max: 5 });
const adapter = new PrismaPg(pool);
const prisma = new PrismaClient({ adapter });
const users = await prisma.user.findMany();
ctx.waitUntil(pool.end());

Note: Prisma requires driver adapters (@prisma/adapter-pg).

---

Local Development

Option 1: Environment Variable (Recommended)

export CLOUDFLARE_HYPERDRIVE_LOCAL_CONNECTION_STRING_HYPERDRIVE="postgres://user:password@localhost:5432/local_db"
npx wrangler dev

Safe to commit config, no credentials in wrangler.jsonc.

Option 2: localConnectionString in wrangler.jsonc

{ "hyperdrive": [{ "binding": "HYPERDRIVE", "id": "prod-id", "localConnectionString": "postgres://..." }] }

⚠️ Don't commit credentials to version control.

Option 3: Remote Development

npx wrangler dev --remote  # ⚠️ Uses PRODUCTION database

---

Query Caching

Cached: SELECT (non-mutating queries) NOT Cached: INSERT, UPDATE, DELETE, volatile functions (LASTVAL, LAST_INSERT_ID)

May 2025: 5x faster cache hits via regional prepared statement caching.

Critical for postgres.js:

const sql = postgres(env.HYPERDRIVE.connectionString, {
  prepare: true  // REQUIRED for caching
});

Check cache status:

response.headers.get('cf-cache-status');  // HIT, MISS, BYPASS, EXPIRED

---

TLS/SSL Configuration

SSL Modes: require (default), verify-ca (verify CA), verify-full (verify CA + hostname)

Server Certificates (verify-ca/verify-full):

npx wrangler cert upload certificate-authority --ca-cert root-ca.pem --name my-ca-cert
npx wrangler hyperdrive create my-db --connection-string="postgres://..." --ca-certificate-id <ID> --sslmode verify-full

Client Certificates (mTLS):

npx wrangler cert upload mtls-certificate --cert client-cert.pem --key client-key.pem --name my-cert
npx wrangler hyperdrive create my-db --connection-string="postgres://..." --mtls-certificate-id <ID>

---

Private Database Access (Cloudflare Tunnel)

Connect to databases in private networks (VPCs, on-premises):

# 1. Install cloudflared (macOS: brew install cloudflare/cloudflare/cloudflared)
# 2. Create tunnel
cloudflared tunnel create my-db-tunnel

# 3. Configure config.yml
# tunnel: <TUNNEL_ID>
# ingress:
#   - hostname: db.example.com
#     service: tcp://localhost:5432

# 4. Run tunnel
cloudflared tunnel run my-db-tunnel

# 5. Create Hyperdrive
npx wrangler hyperdrive create my-private-db --connection-string="postgres://user:password@db.example.com:5432/database"

---

Critical Rules

Always Do

✅ Include nodejs_compat in compatibility_flags ✅ Use ctx.waitUntil(client.end()) for connection cleanup ✅ Set max: 5 for connection pools (Workers limit: 6) ✅ Enable TLS/SSL on your database (Hyperdrive requires it) ✅ Use prepared statements for caching (postgres.js: prepare: true) ✅ Set disableEval: true for mysql2 driver ✅ Handle errors gracefully with try/catch ✅ Use environment variables for local development connection strings ✅ Test locally with wrangler dev before deploying

Never Do

❌ Skip nodejs_compat flag (causes "No such module" errors) ❌ Use private IP addresses directly (use Cloudflare Tunnel instead) ❌ Use await client.end() (blocks response, use ctx.waitUntil()) ❌ Set connection pool max > 5 (exceeds Workers' 6 connection limit) ❌ Wrap all queries in transactions (limits connection multiplexing) ❌ Use SQL-level PREPARE/EXECUTE/DEALLOCATE (unsupported) ❌ Use advisory locks, LISTEN/NOTIFY (PostgreSQL unsupported features) ❌ Use multi-statement queries in MySQL (unsupported) ❌ Commit database credentials to version control

---

Wrangler Commands Reference

# Create Hyperdrive configuration
wrangler hyperdrive create <name> --connection-string="postgres://..."

# List all Hyperdrive configurations
wrangler hyperdrive list

# Get details of a configuration
wrangler hyperdrive get <hyperdrive-id>

# Update connection string
wrangler hyperdrive update <hyperdrive-id> --connection-string="postgres://..."

# Delete configuration
wrangler hyperdrive delete <hyperdrive-id>

# Upload CA certificate
wrangler cert upload certificate-authority --ca-cert <file>.pem --name <name>

# Upload client certificate pair
wrangler cert upload mtls-certificate --cert <cert>.pem --key <key>.pem --name <name>

---

Supported Databases

PostgreSQL (v9.0-17.x): AWS RDS/Aurora, Google Cloud SQL, Azure, Neon, Supabase, PlanetScale, Timescale, CockroachDB, Materialize, Fly.io, pgEdge, Prisma Postgres

MySQL (v5.7-8.x): AWS RDS/Aurora, Google Cloud SQL, Azure, PlanetScale, MariaDB (April 2025 GA)

NOT Supported: SQL Server, MongoDB, Oracle

---

Unsupported Features

PostgreSQL

• SQL-level prepared statements (PREPARE, EXECUTE, DEALLOCATE)
• Advisory locks
• LISTEN and NOTIFY
• Per-session state modifications

MySQL

• Non-UTF8 characters in queries
• USE statements
• Multi-statement queries
• Protocol-level prepared statements (COM_STMT_PREPARE)
• COM_INIT_DB messages
• Auth plugins other than caching_sha2_password or mysql_native_password

Workaround: For unsupported features, create a second direct client connection (without Hyperdrive).

---

Performance Best Practices

1. Avoid long-running transactions - Limits connection multiplexing
2. Use prepared statements - Enables query caching (postgres.js: prepare: true)
3. Set max: 5 for pools - Stays within Workers' 6 connection limit
4. Disable fetch_types if not needed - Reduces latency (postgres.js)
5. Use ctx.waitUntil() for cleanup - Non-blocking connection close
6. Cache-friendly queries - Prefer SELECT over complex joins
7. Index frequently queried columns - Improves query performance
8. Monitor with Hyperdrive analytics - Track cache hit ratios and latency

---

Troubleshooting

See references/troubleshooting.md for complete error reference with solutions.

Quick fixes:

Error	Solution
"No such module 'node:*'"	Add nodejs_compat to compatibility_flags
"TLS not supported by database"	Enable SSL/TLS on your database
"Connection refused"	Check firewall rules, allow public internet or use Tunnel
"Failed to acquire connection"	Use ctx.waitUntil() for cleanup, avoid long transactions
"Code generation from strings disallowed"	Set disableEval: true in mysql2 config
"Bad hostname"	Verify DNS resolves, check for typos
"Invalid database credentials"	Check username/password (case-sensitive)

---

Metrics and Analytics

Hyperdrive Dashboard → Select config → Metrics tab

Available: Query count, cache hit ratio, query latency (p50/p95/p99), connection latency, query/result bytes, error rate

---

Credential Rotation

# Option 1: Create new config (zero downtime)
wrangler hyperdrive create my-db-v2 --connection-string="postgres://new-creds..."
# Update wrangler.jsonc, deploy, delete old config

# Option 2: Update existing
wrangler hyperdrive update <id> --connection-string="postgres://new-creds..."

Best practice: Separate configs for staging/production.

---

References

• Official Documentation
• Get Started Guide
• How Hyperdrive Works
• Query Caching
• Local Development
• TLS/SSL Certificates
• Troubleshooting Guide
• Wrangler Commands
• Supported Databases

---

Last Updated: 2025-11-23 Package Versions: wrangler@4.50.0, pg@8.16.3+ (minimum), postgres@3.4.7, mysql2@3.15.3 Production Tested: Based on official Cloudflare documentation and community examples