Patterns

These patterns document repeatable implementation shapes used across Archipel. Use them when adding platform library code, application integration code, or AI-assisted scaffolding that must follow repository conventions.

Pattern	What it covers
Configuration Pattern	Typed config keys, registry entries, and ConfigModule integration.
DTO & Validation Pattern	Request and response classes, validation decorators, and OpenAPI metadata.
Error Handling Pattern	Domain errors, exception filters, and structured error envelopes.
Guard & Interceptor Pattern	Metadata decorators, guards, interceptors, and request enforcement.
Mapping Pattern	Type-safe mapping keys, profiles, and MappingService usage.
Dynamic Module Pattern	NestJS dynamic module registration and dependency wiring.
Query Pattern	Repository query objects and transactional query execution.
Repository Pattern	RepositoryBase subclasses and Prisma delegate isolation.
Testing Pattern	Vitest structure, mocks, and integration test conventions.
Bootstrap Pattern	Composable NestJS startup with PlatformApplication and PlatformBootstrapStep.