Express HTTP Problem Details

Express middleware for RFC 7807 HTTP Problem Details content negotiation. Current stable version 0.2.1. It integrates with http-problem-details-mapper to map custom Node.js errors to standard Problem Documents. Key differentiators: automatic content negotiation based on Accept header, ships TypeScript types, and builds on the PDMLab ecosystem of problem-details libraries. Release cadence is low, with the last release in 2020.