Edge-first bash

Sometimes you just want a shell — grep, sed, awk, pipes — but you're somewhere without one: an edge function, a serverless handler, a browser. Because Lifo is pure JavaScript with an in-memory filesystem and no native dependencies, it runs where a real shell can't: Cloudflare Workers, Vercel Edge, Deno, or a browser tab. No binary, no container, sub-millisecond boot.

A shell in a handler#

import { Sandbox } from "@lifo-sh/core";

// Boot per request — it's cheap. Volatile by default: nothing persists.
const box = await Sandbox.create();

box.fs.writeFile("/tmp/log.txt", rawLogText);

const { stdout } = await box.commands.run(
  "grep ERROR /tmp/log.txt | sed 's/^/[!] /' | sort | uniq -c | sort -rn",
);
return new Response(stdout);

You get the real coreutils pipeline — 60+ commands including grep, sed, awk, cut, sort, uniq, tr, head/tail, tar, jq-style text munging — evaluated in-process against the box's virtual filesystem.

Text processing without touching a disk#

You don't need real files. Pipe data straight through with stdin:

const { stdout } = await box.commands.run("awk '{ sum += $1 } END { print sum }'", {
  stdin: numbersOnePerLine,
});

Why it fits the edge#

• No cold start — there's no image to initialize; a box is a few objects.
• No native deps — nothing to compile or bundle a binary for; it tree-shakes like any dependency.
• Volatile is fine — edge invocations are ephemeral, and a box defaults to an in-memory filesystem with nothing to clean up.

Next#

• Commands — the full coreutils set and how to add your own.
• Browser vs Node — what changes across environments.