Dart Macros — Compile-time Code Generation Without Build Runner Dart 3.4 (Flutter 3.22) introduced Dart Macros as an experimental feature: compile-time code generation that works without build_runner . A single annotation can auto-generate fromJson / toJson , copyWith , or Equatable -style equality — all processed directly by the compiler. What Are Dart Macros? Key Differences from build_runner Traditional build_runner -based code generation has two pain points: Slow build steps : You must manually run dart run build_runner build , which can take seconds to minutes on large projects Generated file clutter : The .g.dart files need to be committed (or .gitignore d), causing team disagreements Dart Macros are processed by the compiler itself, eliminating the separate build step. IDE autocomplete works immediately, and there are no .g.dart files written to disk.…