Cloudflare Developer Skill

Expertise in Cloudflare Workers, Pages, D1, R2, KV storage, AI integration, security best practices, deployment, and performance optimization.

Cloudflare Developer Platform Skill

Description

Complete Cloudflare Developer Platform knowledge: Workers, Pages, D1, R2, KV, AI, security best practices, and deployment patterns.

Quick Actions

Deploy Workers

# Init new Worker
wrangler init my-worker

# Dev local
wrangler dev

# Deploy production
wrangler deploy

Setup D1 Database

# Create database
wrangler d1 create my-db

# Add to wrangler.toml
[[d1_databases]]
binding = "DB"
database_name = "my-db"
database_id = "xxx"

# Run migrations
wrangler d1 migrations apply my-db

Setup R2 Bucket

# Create bucket
wrangler r2 bucket create my-bucket

# Add to wrangler.toml
[[r2_buckets]]
binding = "MY_BUCKET"
bucket_name = "my-bucket"

Decision Trees

Storage Choice

• Config, feature flags, session tokens → KV
• Structured data (SQL tables) → D1
• Files, uploads, backups → R2

SSL/TLS Mode

• Origin has valid cert → Full (strict) ✅
• Origin self-signed cert → Full
• Origin HTTP only → Flexible (last resort)

Cache Strategy

• Static assets (/assets/*, *.css, *.js) → Cache, long TTL
• Public HTML (no session) → Cache, medium TTL
• Dynamic HTML (session) → Bypass
• API with auth → Bypass
• Admin/checkout → Bypass

Best Practices

Workers

• Always use bindings (env.KV, env.DB, env.MY_BUCKET) instead of REST API
• Await all Promises or use ctx.waitUntil() for background tasks
• Custom domain: Worker as origin, DNS record must be proxied (orange cloud)
• Debug: wrangler tail

D1

• Create indexes for columns in WHERE clause (email, user_id)
• ONLY index frequently queried columns
• Run migrations: wrangler d1 migrations apply

Security

• WAF rollout: Log → Simulate (24-48h) → Block
• SSL: Full (strict) when you have valid cert
• DO NOT proxy MX records
• Origin firewall: only allow Cloudflare IPs

Performance

• Enable Tiered Cache (free)
• DO NOT cache HTML with sessions → data leak
• Bypass cache for /admin, /checkout, /api with cookies
• Check CF-Cache-Status header

Common Mistakes & Fixes

Issue	Cause	Fix
Worker 404	Route missing DNS proxied	Add DNS record + orange cloud
Email down	MX record proxied	Remove proxy from MX
Redirect loop	SSL Flexible + HTTPS origin	Change to Full (strict)
Data leak	Cache HTML with session	Bypass dynamic pages
KV inconsistent	Eventually consistent model	Use D1 for transactional data
D1 slow	Missing index	Index columns in WHERE

Architecture Patterns

Fullstack App

User → Pages (frontend) → Pages Functions (/api/*) → D1 + KV + R2

API with Workers

Client → Custom domain (Worker) → D1/KV/external API

RAG with Workers AI

User → Worker → AI Gateway → Workers AI (embedding) → Vectorize → LLM

Troubleshooting

Worker not running

1. Check wrangler.toml routes
2. Verify DNS record proxied (orange cloud)
3. Check wrangler tail logs
4. Test with wrangler dev local

D1 migration error

1. Check SQL syntax
2. Verify binding in wrangler.toml
3. Dry run: wrangler d1 migrations list

Cache not hitting

1. Check CF-Cache-Status header
2. Verify Cache Rules
3. Enable Tiered Cache
4. Review bypass rules

Resources

• Official docs: https://developers.cloudflare.com/
• Learning Hub: https://onboarding.orangecloud.vn/
• Changelog: https://developers.cloudflare.com/changelog/
• Community: https://community.cloudflare.com/

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Last updated: 2026-06-03
Source: Cloudflare Starter Hub complete learning path