API Developer Hub

Build practical API development knowledge, one topic at a time. API Developer Hub brings 320 guided lessons into one focused learning workspace. Explore concepts, inspect examples and practice with challenges designed around real API engineering decisions. 16 LEARNING PATHS • HTTP foundations and REST resource design • JSON schemas and validation • Identity, OAuth, JWT and authorization • API security engineering • Node.js and FastAPI development • Databases and transactions • Testing and quality • Documentation and OpenAPI • Performance, caching and reliability • GraphQL and realtime APIs • Webhooks and API clients • Deployment and observability • 20 applied API project briefs LEARN WITH STRUCTURE Every topic includes an explanation, a focused example, a guided practice task, a failure mode to review and a knowledge check. Examples include code snippets, protocol messages and pseudocode; they are learning references rather than complete backend projects. YOUR PERSONAL WORKSPACE Search the lesson library, bookmark useful concepts, track completed lessons and return to your latest topic. Increase reading size and enable an optional daily reminder at your chosen time. LOCAL DEVELOPER TOOLS Format JSON objects and arrays, encode or decode URL components and inspect JWT payloads locally. The JWT inspector decodes content only; it does not verify signatures or establish token trust. OFFLINE LEARNING The full lesson catalog is bundled with the app. All 256 free lessons work offline. The remaining 64 premium lessons can each be unlocked by voluntarily watching a rewarded ad when an ad is available; earned access is saved on the device. Ads and new rewarded unlocks require an internet connection. Progress, bookmarks, settings and earned unlocks are stored on your device. Clearing app data or uninstalling removes them. There is no account or cloud sync. Contains ads. The app is an independent educational resource and is not affiliated with programming frameworks or API platforms. Learning content does not provide a professional certification.