Swapping Tools Mid-Conversation Without Losing Your Prompt Cache
Tools can now be added and removed between turns, but the tool block sits at the very front of the cache prefix. I measured 12 mutation patterns with fingerprints and built a stable-core plus volatile-tail registry with a guard that refuses unsafe changes.
Claude Vision API in Production — Implementation Patterns for Image Analysis, PDF Processing, and OCR
Implementation patterns for taking Claude's vision capabilities to production: choosing between Base64, URL, and the Files API, native PDF processing, schema-enforced extraction with Tool Use, batch cost reduction, and error recovery — all with working code.
Archiving Claude API Responses to Cloudflare R2: An Implementation Memo for Audit, Replay, and Incident Analysis
An implementation memo on persisting Claude API requests and responses into Cloudflare R2 so you can audit, replay, and triage production incidents — covering Workers waitUntil patterns, PII masking, and a D1 metadata index for fast lookups.
Automating Wallpaper Classification with Claude Vision API — Accuracy, Cost, and a Batch Job That Survives Interruptions
A firsthand account of automating wallpaper category classification with the Claude Vision API. Honest numbers on accuracy and cost, plus the batch design that stopped me re-paying for the same images.
6 Traps I Hit Building In-App AI Chat with Claude API — A Record of Getting to Production
Six real design mistakes I encountered shipping Claude API in-app chat to production — covering context management, streaming error detection, guardrails, session persistence, model versioning, and cost monitoring. Includes working TypeScript code.
Combining Haiku 4.5, Streaming, and Prompt Caching to Cut Costs in a Personal App — An Implementation Record
A hands-on record of combining Claude Haiku 4.5, streaming, and prompt caching to improve both cost and response speed in a personal iOS/Android app — including the mistakes made along the way.
Claude API on Bun in Production: Migration Decisions and Implementation Patterns That Actually Survive Real Traffic
A practical guide to running Claude API services on Bun in production. Covers migration triggers from Node.js, built-in SQLite/WebSocket usage, streaming optimization, and the pitfalls that only surface after deployment — with working code and measured numbers.
Designing a Claude API Monthly Budget That Doesn't Blow Up — Cost Management for Solo Developers
When you embed Claude API into a side-project app, the first thing you hit is the end-of-month invoice. Here are the budgeting math, logging, caps, and retry rules I use to keep costs predictable, including the places where I tripped.
Building a Production Multilingual Translation SaaS with Claude API — Glossaries, Style, and Domain Adaptation in Practice
A practical, code-first design guide for running a translation SaaS on Claude API: glossaries, style guides, domain adaptation, quality gates, and cost controls that survive real production traffic.
Indie Developer's Claude API SaaS Launch Blueprint — A 90-Day Roadmap from Idea to Paying Customers
A complete 90-day roadmap for building an indie Claude API business: idea validation, Stripe integration, SEO, subscription pricing tests, and the operational and emotional discipline that makes it last. Drawing on twelve years of solo app development and the new realities of AI APIs.
Claude API Revenue Models Compared — Pay-per-Use, Subscription, One-Shot, and Revenue Share for Indie Developers
When you build something with Claude API to make money, the hardest decision is rarely the API itself — it's the pricing model. This guide compares the four most common models from an indie developer's point of view.
Decoding Claude's 'Spanner Temporarily Unavailable' Error and How to Handle It
The 'Spanner temporarily unavailable' error occasionally appears in Claude API and Claude.ai responses. This guide unpacks what the message reveals about Anthropic's infrastructure and walks through practical retry strategies that production teams actually use.