NestJS Best Practices

Use the project's source, package manifest, lockfile, module format, HTTP adapter, and test runner as the primary context. Read only the references relevant to the task.

This skill targets NestJS 12. The npm latest tag for @nestjs/core was verified as 12.0.1 on 2026-08-29. Treat that patch number as a dated observation: re-check the registry and official documentation before recommending or performing an upgrade.

Version Gate

1. Inspect package.json and the lockfile for @nestjs/core, @nestjs/common, platform adapters, CLI, and companion packages.
2. Preserve the installed major for ordinary feature and bug-fix work. Do not introduce v12-only APIs into a v10/v11 project.
3. For a new project or an explicit upgrade, verify the current stable npm tag and official migration guide. Keep all @nestjs/* packages on compatible majors.
4. For v11 to v12 work, read NestJS 12 migration before editing dependencies or configuration.
5. Preserve the project's CommonJS or ESM choice unless the user requests a module-format migration. Nest 12 packages are ESM, but supported CommonJS applications can consume them on compatible Node.js versions.

Working Method