Deno Standard Library
Use the independently versioned Deno standard-library packages published on JSR
The Deno Standard Library is not a set of runtime globals. It is a collection of independently versioned modules under the JSR @std scope. Install only the packages the project uses:
deno add jsr:@std/path jsr:@std/fs jsr:@std/assert
import { join } from "@std/path";
import { ensureDir } from "@std/fs";
import { assertEquals } from "@std/assert";
await ensureDir(join("data", "cache"));
assertEquals(join("data", "file.txt"), "data/file.txt");
Common packages
| Task | Package | Note |
|---|---|---|
| portable paths | @std/path | do not concatenate / manually |
| file helpers | @std/fs | still subject to Deno permissions |
| test assertions | @std/assert | pair with Deno.test |
| date and time helpers | @std/datetime | marked UNSTABLE on JSR and never stabilized with std 1.0; prefer Web Temporal / Intl |
| UUIDs | Web crypto.randomUUID() | usually no package required |
| HTTP | Deno.serve | add a framework for routing or sessions |
Standard-library packages have no third-party dependencies and aim to work across Deno, Node, Bun, Workers, and browsers where the underlying platform API exists.
Official references: Deno Standard Library and JSR @std.