What are the two ways to register a global exception filter in NestJS and what is the key difference?
app.useGlobalFilters() registers the filter outside the DI container — it cannot inject services. The APP_FILTER token registers the filter as a NestJS provider with full DI support, making it the preferred approach for any filter that needs to inject LoggerService, Sentry clients, or other dependencies.
Both global filter registration methods
Key differences between the two methods:
app.useGlobalFilters() — simple, works for stateless filters with no dependencies.
APP_FILTER token — filter is a NestJS provider with full constructor injection.
Multiple APP_FILTER providers can be registered — they run in registration order.
APP_FILTER is the only option when the filter needs to inject LoggerService, Sentry, or ConfigService.
APP_FILTER is imported from @nestjs/core — not @nestjs/common.