dkmqflx NestJS Configuration
Best practices for configuring a NestJS application with @nestjs/config (v10/v11),
based on the official documentation (https://docs.nestjs.com/techniques/configuration).
Each rule pairs an incorrect example with the official correct pattern. Priorities run
from security and fail-fast correctness (CRITICAL) down to ergonomics and performance.
When to Apply
Reference these guidelines when:
- Registering
ConfigModule.forRoot()in the root/app module - Reading environment variables anywhere in the app (services, providers,
main.ts) - Validating environment at boot with Joi or class-validator
- Grouping related config with
registerAs()namespaces and typed access - Handling secrets,
.envfiles, and.env.example - Reviewing or refactoring how a NestJS app reads configuration
Rules
| Impact | Rule | Summary |
|---|---|---|
| CRITICAL | no-secrets-in-repo |
Keep secrets in env/secret manager; commit only .env.example |
| CRITICAL | validate-env-schema |
Validate env at boot so misconfig fails fast |
| HIGH | global-config-module |
ConfigModule.forRoot({ isGlobal: true }) once, at the root |
| HIGH | configservice-over-process-env |
Inject ConfigService; don't read process.env scattered everywhere |
| MEDIUM | namespaced-typed-config |
registerAs() namespaces + typed access for grouped config |
| MEDIUM | type-safe-get |
Type get<T>() / use infer: true to avoid undefined surprises |
| LOW | cache-config |
cache: true for performance; mind env-file load order |
How to Use
Read the individual rule file for the explanation and before/after example:
rules/no-secrets-in-repo.md
rules/validate-env-schema.md
rules/global-config-module.md
rules/configservice-over-process-env.md
rules/namespaced-typed-config.md
rules/type-safe-get.md
rules/cache-config.md
Each rule file contains:
- A short explanation of why it matters, tied to the official docs
- An Incorrect example (the antipattern)
- A Correct example (the official pattern)
All examples target @nestjs/config for NestJS v10/v11 and avoid deprecated APIs.