Application, Server & Database

Application

Variable	Default	Description
`RUNIQUE_ENV`	`prod`	`dev` or `prod`, whatever the case; unset or unknown means `prod` (with a warning for an unknown value). Read once at startup. In `dev`: session cookie without `Secure`, `debug` log level (unless `RUST_LOG`), templates read again on every request, no-cache headers on `localhost`, the default home page when `/` isn't declared, public URL set to `http://127.0.0.1:{PORT}` (`.with_public_url()` ignored), allowed hosts not validated, no `upgrade-insecure-requests`, no SRI and static files in `no-cache`, so edited CSS reloads without a restart. In `prod`: security checks at startup (`SECRET_KEY`, `with_public_url`, the reset's mailer, ACME).
`DEBUG`	`false`	Shows the detailed error pages and changes nothing else — read once at startup. Accepts `true`/`1`/`yes`/`on` and `false`/`0`/`no`/`off`, whatever the case. Also works with `RUNIQUE_ENV=prod` to look into a problem on a live site: not recommended, as every visitor then sees those pages (a warning shows at startup).
`BASE_DIR`	`.`	Application root directory
`TZ`	`UTC`	IANA timezone for the application (e.g. `Europe/Paris`, `America/New_York`). Accessible via `config.timezone` — parse it with `chrono-tz` in your project.
`LANG`	system locale	CLI language (`fr`, `en`, `de`, `es`, `it`, `pt`, `ja`, `zh`, `ru`). Priority: `LANG` / `LC_ALL` / `LC_MESSAGES` from `.env` > system locale > `en`. The app's language is set in code (`set_lang(Lang::En)`)

Server

Variable	Default	Description
`IP_SERVER`	`127.0.0.1`	Listening IP address
`PORT`	`3000`	Listening port
`SECRET_KEY`	`default_secret_key`	Secret key (CSRF, signatures, encryption of the sessions in the database: changing it signs their users out at restart). `runique new` writes a random one (64 hex characters) into the project's `.env`. To replace it: any random string of 32 characters or more (`openssl rand -hex 32`). In production (`RUNIQUE_ENV=prod`), startup fails when it is empty, equal to the default, or shorter than 32 characters; in development, a warning is shown when it is missing

Database

Connection

Variable	Default	Description
`DATABASE_URL`	—	Full URL. Read first: when set, `DB_ENGINE`, `DB_USER`, `DB_PASSWORD`, `DB_HOST`, `DB_PORT` and `DB_NAME` are ignored, and the engine comes from the URL's scheme (`postgres://`, `mysql://`, `mariadb://`, `sqlite://`)
`DB_ENGINE`	`sqlite`	Engine, when `DATABASE_URL` is unset: `postgres`, `mysql`, `mariadb`, `sqlite`. Must match the compiled `runique` feature, or startup fails with "driver not enabled"
`DB_USER`	—	Username (required except for SQLite)
`DB_PASSWORD`	—	Password (required except for SQLite)
`DB_HOST`	`localhost`	Host
`DB_PORT`	`5432` / `3306`	Port (default depends on engine)
`DB_NAME`	`local_base.sqlite` (SQLite only)	Database name — required for postgres/mysql/mariadb, startup fails if absent

Connection pool

Variable	Default	Description
`DB_MAX_CONNECTIONS`	`100`	Maximum pool size
`DB_MIN_CONNECTIONS`	`20`	Minimum pool size

Timeouts

Variable	Default	Unit	Description
`DB_CONNECT_TIMEOUT`	`2`	seconds	Connection establishment timeout
`DB_ACQUIRE_TIMEOUT`	`500`	milliseconds	Pool acquire timeout
`DB_IDLE_TIMEOUT`	`300`	seconds	Idle connection lifetime
`DB_MAX_LIFETIME`	`3600`	seconds	Maximum connection lifetime

SQL Logging

Variable	Default	Description
`DB_LOGGING`	`false`	Enable SQL query logging (`true`, `1`, `yes`)

Secondary connections — `with_custom_db`

To attach an additional database connection (Redis pool, secondary PostgreSQL, MongoDB client, etc.), use .with_custom_db() on the builder. The value is stored in a HashMap<TypeId, Arc<dyn Any>> internal to RuniqueEngine — not injected as an Axum Extension. Access it in handlers via engine.custom_db::<T>() (or its alias engine.extension::<T>()), which returns Option<Arc<T>>.

// main.rs
let redis = redis::Client::open("redis://127.0.0.1/")?;
let db = DatabaseConfig::from_env()?.build().connect().await?;

RuniqueApp::builder(config)
    .with_database(db)
    .with_custom_db(redis)   // T: Any + Send + Sync + 'static
    .routes(url::routes())
    .build().await?
    .run().await

// handler
use redis::Client;

pub async fn my_handler(mut req: Request) -> AppResult<Response> {
    let redis = req.engine.custom_db::<Client>().expect("redis not configured");
    let mut conn = redis.get_async_connection().await?;
    // ...
}

Any type implementing Any + Send + Sync + 'static is accepted. Multiple secondary connections of different types can be registered with repeated .with_custom_db() calls.