Config Env Parameters (Symfony)

Use when

• Adding or changing an environment variable, a parameter, or a secret.
• A value differs between environments (dev, test, prod).
• Casting or parsing env values (int:, bool:, json:, csv:, file:).
• Storing credentials in the Symfony secrets vault.

Default workflow

1. Decide where the value lives: .env default, .env.local, real environment, or the vault for secrets.
2. Declare it with a safe committed default, never a real credential.
3. Inject it with %env(...)% and the right processor, through a parameter or #[Autowire].
4. Put environment-specific settings in config/packages/<env>/ or when@<env> blocks.
5. Fail fast in the service when a required value is empty.