Building an API with Cloudflare Workers and D1#

This tutorial walks through building a production API on Cloudflare Workers with a D1 database, KV caching, rate limiting, full-text search, and request logging. The patterns come from a real production deployment – not a toy example.

By the end you will have: a TypeScript Worker handling multiple API routes, a D1 database with FTS5 full-text search, KV-based caching and rate limiting, CORS support, request logging with IP hashing for privacy, and a deployment to Cloudflare’s global network.

Choosing a Deployment Platform for APIs and MVPs#

Picking a deployment platform early in a project matters more than most teams realize. The platform determines your cost floor, your scaling ceiling, your deployment workflow, and how much operational overhead you carry. Switching later is possible but never free – you are always migrating data, rewriting config, and updating DNS.

This guide compares four platforms that cover the most common deployment scenarios: Cloudflare (Workers + D1 + Pages), AWS (Lambda + API Gateway + RDS + S3), Vercel (Pro + serverless functions), and Fly.io (Apps + Postgres). Each has a genuine sweet spot. None is best for everything.

Cloudflare Workers as a Full-Stack Platform#

Cloudflare started as a CDN and DDoS protection service. It is now a complete development platform. Workers provide serverless compute at 330+ edge locations. D1 provides a serverless SQLite database. KV provides a globally distributed key-value store. R2 provides S3-compatible object storage with zero egress fees. Pages provides static site hosting with git-integrated deploys. Durable Objects provide stateful, single-threaded coordination primitives. Queues provide async message processing between Workers.

Comparing Serverless Platforms#

Choosing a serverless platform is not about which one is “best.” Each platform makes different tradeoffs around cold start latency, execution limits, pricing granularity, and ecosystem integration. The right choice depends on what you are building, what cloud you already use, and which constraints matter most.

This framework compares the four major serverless compute platforms as of early 2026: AWS Lambda, Google Cloud Run, Azure Functions, and Cloudflare Workers.

SQLite for Production Use#

SQLite is not a toy database. It handles more read traffic than any other database engine in the world – every Android phone, iOS device, and major web browser runs SQLite. The question is whether your workload fits its concurrency model: single-writer, multiple-reader. If it does, SQLite eliminates an entire class of operational overhead with no server process, no network protocol, and no connection authentication.

WAL Mode#

Write-Ahead Logging (WAL) mode is the single most important configuration for production SQLite. In the default rollback journal mode, writers block readers and readers block writers. WAL removes this limitation.

Zero-Egress Architecture with Cloudflare R2#

Every major cloud provider charges you to download your own data. AWS S3 charges $0.09/GB. Google Cloud Storage charges $0.12/GB. Azure Blob charges $0.087/GB. These egress fees are the most unpredictable line item on cloud bills – they scale with success. The more users download your data, the more you pay.

Cloudflare R2 charges $0 for egress. Zero. Unlimited. Every download is free, whether it is 1 GB or 100 TB. R2 uses the S3-compatible API, so existing tools and SDKs work without changes. This single pricing difference changes how you architect storage, serving, and cross-cloud data flow.