Config

Typed access to environment variables and the current runtime environment.

Config is a static façade over process.env — nothing is cached, so a read always reflects the current value. Beyond convenience, it is what the framework itself consults for environment-dependent behaviour: App checks Config.nodeEnv before exiting the process on App.close.

Declare your variables on Env in your own code to get autocompletion and a checked key for every lookup.

const port = Config.get("PORT", { parser: Number, fallback: 3000 });
const secret = Config.require("JWT_SECRET");

Config

class

class Config

Static accessor for environment variables.

Every read goes straight to process.env, so a variable set after startup — by a test, or by Config.set — is visible immediately.

The three lookups differ in how they treat a missing value: Config.get returns undefined or a fallback, Config.require throws, and Config.has only reports presence.

Config.env

static get env(): NodeJS.ProcessEnv

The live process.env object.

Returns — The environment, unwrapped. Reading it directly bypasses the parsing and fallback handling of Config.get.

Config.nodeEnv

static get nodeEnv(): NodeEnv

The current environment name.

Returns — The value of NODE_ENV, or "development" when it is unset — an unconfigured process is treated as a development one.

Config.isProd

static get isProd(): boolean

Returns — true when Config.nodeEnv is "production".

Config.isDev

static get isDev(): boolean

Returns — true when Config.nodeEnv is "development", including when NODE_ENV is unset.

Config.isTest

static get isTest(): boolean

Returns — true when Config.nodeEnv is "test". App.close checks this to avoid exiting the process out from under a test runner.

Config.has()

static has(key: EnvKey): boolean

Reports whether a variable is set, without reading its value.

Parameters

• key — The variable name to check.

Returns — true when the variable is defined. An empty string counts as defined.

Config.get()

static get(key: EnvKey): string | undefined;
static get<T = string>(key: EnvKey, opts: { parser?:(raw: string)=>T; fallback: T }): T;
static get<T = string>(key: EnvKey, opts: { parser:(raw: string)=>T; fallback?: T }, ): T | undefined;
static get<T = string>(key: EnvKey, opts?: { parser?:(raw: string)=>T; fallback?: T }, ): T | undefined

Reads a variable as a raw string.

Reads a variable with a guaranteed result, since a fallback covers the unset case.

Reads and converts a variable with no fallback.

Parameters

• key — The variable name to read.

Returns — The value, or undefined when unset.

Config.require()

static require(key: EnvKey): string;
static require<T = string>(key: EnvKey, parser:(raw: string)=>T): T;
static require<T = string>(key: EnvKey, parser?:(raw: string)=>T): T | string

Reads a variable that the application cannot run without.

Reads and converts a variable that the application cannot run without.

Parameters

• key — The variable name to read.

Returns — The raw value.

Throws — Error when the variable is unset.

Throws — Error when the variable is unset. The parser is never called in that case, so it can assume a real value.

Config.set()

static set(key: string, value: string | number | boolean): void

Writes a variable into the environment, stringifying the value the way the environment stores everything.

Mutates the real process.env, so the change is visible to every reader in the process, not only to Config.

Parameters

• key — The variable name to write.
• value — The value to store; numbers and booleans are converted to their string form.

Env

interface

interface Env

Declaration target for an application's environment variables.

Empty by design. Augment it from your own code and every key you add becomes a suggested EnvKey:

declare module "corpus" {
	interface Env {
		DATABASE_URL: string;
		JWT_SECRET: string;
	}
}