When Claude API Document Extraction Is Confidently Wrong — Field Notes on Catching Silent Errors with Invariants
In structured extraction from invoices and contracts, the real danger isn't a crash — it's a value that's silently wrong while the schema validates and confidence reads high. Field notes on invariants, two-pass extraction, and tracking field-level error rates.
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.
Claude API Files API — Persist Documents and Slash API Costs
Learn how to use Claude API's Files API to persist documents and avoid re-uploading costs. Upload PDFs and long documents once, reuse them across multiple API requests with this practical implementation guide.