Skip to main content
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.