The runtime-neutral PTY contract for Node, Bun, and Deno.

Quick start

Acquire a ready Backend, hand it to Core, spawn a shell with a structured argv — no string commands, no implicit shell.

import { UniPty } from "unipty";
import { createNodePtyBackend } from "@unipty/backend-node-pty";

// 1. Acquire a ready Backend (one-time, asynchronous).
const backend = await createNodePtyBackend();

// 2. Core accepts only a structurally ready Backend.
const unipty = new UniPty({ backend });

// 3. Spawn: argv is non-empty, argv[0] is the executable.
const pty = unipty.spawn(["/bin/sh", "-i"], {
  terminal: { cols: 80, rows: 24 },
});

// 4. Consume Terminal Text (or Terminal Bytes with "bytes").
for await (const chunk of pty.stream({ encoding: "utf8" })) {
  process.stdout.write(chunk);
}

// 5. Write with boolean readiness; drain when Core says pause.
if (!pty.write("echo hello\r")) {
  await pty.drain();
}

// 6. Observe process exit independently of the stream.
const { exitCode, signal } = await pty.exited;

The same Core contract runs on every official Backend route. Swapping routes means swapping the Backend you acquire — nothing else changes.

Official Backend routes

Which tuples are actually verified for the current release? See the compatibility catalog.