Skip to main content
Using Deno in production at your company? Earn free Deno merch.
Give us feedback
interface Deno.Env

An interface containing methods to interact with the process environment variables.


get(key: string): string | undefined

Retrieve the value of an environment variable.

Returns undefined if the supplied environment variable is not defined.

console.log(Deno.env.get("HOME"));  // e.g. outputs "/home/alice"
console.log(Deno.env.get("MADE_UP_VAR"));  // outputs "undefined"

Requires allow-env permission.

set(key: string, value: string): void

Set the value of an environment variable.

Deno.env.set("SOME_VAR", "Value");
Deno.env.get("SOME_VAR");  // outputs "Value"

Requires allow-env permission.

delete(key: string): void

Delete the value of an environment variable.

Deno.env.set("SOME_VAR", "Value");
Deno.env.delete("SOME_VAR");  // outputs "undefined"

Requires allow-env permission.

has(key: string): boolean

Check whether an environment variable is present or not.

Deno.env.set("SOME_VAR", "Value");
Deno.env.has("SOME_VAR");  // outputs true

Requires allow-env permission.

toObject(): { [index: string]: string; }

Returns a snapshot of the environment variables at invocation as a simple object of keys and values.

Deno.env.set("TEST_VAR", "A");
const myEnv = Deno.env.toObject();
Deno.env.set("TEST_VAR", "B");
console.log(myEnv.TEST_VAR);  // outputs "A"

Requires allow-env permission.