All Articles
When Claude API Extracts the Wrong Value With Full Confidence — Designing the Verification Layer
When you extract invoices or contracts with Claude API, the scariest failure isn't an exception — it's plausible-but-wrong JSON. Here is how I build a verification layer that catches silent extraction errors with schema checks, arithmetic reconciliation, and dual-extraction agreement, in TypeScript.
When an Announced Billing Change Gets Paused at the Last Minute: Designing Automation That Doesn't Rush the Cutover
A billing change that was supposed to take effect on June 15 was paused that same day. If your pipeline trusts the announced date, a retraction breaks it twice. Here is a design that decides the cutover from a runtime signal, with implementation code.
Stop Terminology Drift in Localized Apps: A Consistent Localizable.strings Pipeline with the Batch API and a Cached Glossary
Translating UI strings one at a time invites inconsistency. Pair Claude's Message Batches API with a prompt-cached glossary to translate Localizable.strings across 10+ languages consistently, with measured costs and the pitfalls I hit in production.
When an Announced Billing Change Is Withdrawn at the Last Minute, Change No Code
A billing change that was supposed to take effect was withdrawn on the day. To survive announce, apply, and revert without touching code, I keep platform behavior behind a single flag and project the monthly delta from real logs.
It Says '500' in the Browser but curl Returns 200 — When a Next.js Error Boundary Misreads a ChunkLoadError
A production Next.js article page shows '500 Internal Server Error' in the browser, yet curl returns 200. The culprit was not the server but a ChunkLoadError surfacing through error.tsx. Here is the diagnosis and a fix with built-in auto-reload.
Making the Numbers Add Up in a Multi-Tenant Claude API SaaS — Field Notes on Isolation and Cost Attribution
The first thing that breaks when you make a Claude API SaaS multi-tenant is the month-end reconciliation. Here are field notes on a single metering chokepoint, atomic counters, reconciling against Anthropic's bill, and proving tenant isolation with adversarial tests — with production TypeScript.
Keep a Decision Rationale Ledger for Autonomous Agents — So You Can Explain 'Why' Later
When an autonomous agent takes hard-to-reverse actions like a production deploy or a bulk delete, capture the chosen option, rejected alternatives, and assumptions in a structured ledger. Includes structured output, an append-only log, and tiering by impact.
Taming Token Bloat in Long-Running Agents with Context Editing and the Memory Tool
For long-running agents whose input tokens balloon as tool results pile up, here is how to pair context editing with the memory tool and measure the savings with count_tokens, including a working backend implementation.
Trusting Claude's Structured Output in Production — Validation Gates and Repair Loops
When Claude's structured output breaks 'occasionally' in production, combine tool-use enforcement, a schema validation gate, a single repair loop, and a graceful degradation fallback to eliminate broken JSON from your operations — with working TypeScript code.
Keeping Large Claude Code Refactors Revertible One Commit at a Time — Field Notes on Checkpoints and Rollback Detection
Hand a big refactor to Claude Code and the speed hides a real cost: review-proof, oversized diffs. Here are the field notes I actually run — declaring checkpoints in a manifest, enforcing commit granularity with a pre-push hook, and tying rollback calls to observability.
Confirm Your Model Actually Responds Before a Scheduled Run Begins
A model you configured can be gone before your nightly job even wakes up. Tell retirement, withdrawal, and regional restriction apart with a single startup probe, then rewrite the run config to an eligible model — with complete, working TypeScript.
PII Masking for Claude API Lives or Dies on the Ledger — Restore, Encrypt, Measure
The hard part of masking PII before Claude API isn't detection — it's operating the token ledger you restore from. Encrypted storage, multi-instance sharing, and a daily leak-rate loop, with working code.