A step-by-step guide to building a compact API gateway using Koa.js that validates route parameters, proxies requests to JSONPlaceholder, fans out parallel upstream calls, and enriches responses with a derived fullAddress field. The tutorial also covers integrating AppSignal for Node.js observability, including automatic Koa middleware tracing, error incident reporting, and global error handling middleware. Practical extensions like caching, rate limiting, authentication, and circuit breaking are outlined as next steps.
Table of contents
Setting Up the ProjectIntegrating AppSignal for MonitoringUnderstanding Koa's Middleware ModelBuilding the API Gateway EndpointsError Handling and Monitoring with AppSignalNext StepsConclusionSort: