API Reference

Every Tynd app has three surfaces:

Backend (@tynd/core) — imported by backend/main.ts, exposes app.start, emitters, lifecycle hooks.
Frontend RPC (@tynd/core/client) — typed proxy to your backend functions via createBackend<typeof backend>().
OS APIs (@tynd/core/client) — direct bridge from the frontend to the Rust host: dialog, window, clipboard, shell, notification, tray, process, fs, http, websocket, sql, sidecar, terminal, store, os, path, compute, and more.

Lite vs full parity. All OS APIs live in Rust (packages/host-rs/src/os/) so both runtimes expose the exact same surface. See Runtime Modes for JS-runtime differences.

Backend

@tynd/core — app.start, app.onReady, app.onClose, createEmitter, AppConfig, WindowConfig, menu/tray config.
Streaming RPC — async-generator handlers.

OS APIs

app

Name, version, exit, relaunch.

tyndWindow

Window control, events, multi-window.

monitors

Enumerate displays, scale factors.

dialog

Native pickers, message / confirm.

clipboard

Text / image / HTML.

shell

Open URLs and files in default handler.

notification

Native OS notifications.

tray

System tray + menu.

App menu bar click handlers.

shortcuts

Global system-wide hotkeys.

Filesystem — text, binary, watcher.

path

Cross-OS path helpers.

Platform, arch, system dirs.

process

Subprocess exec + shell exec.

sidecar

Bundled binaries — resolve runtime path.

HTTP client, upload/download progress.

Offload CPU-bound JS to OS threads.

compute

Rust-native hash + CSPRNG.

keyring

OS-encrypted secret storage.

autolaunch

Start at system boot.

singleInstance

Single-launch lock + deep links.

updater

Ed25519-signed auto-update.

web

Fetch, WebSocket, crypto, URL — Web globals.

Web-platform re-exports

@tynd/core/client also re-exports the standard Web globals as named exports so import * as tynd surfaces them in one namespace alongside the Tynd OS APIs:


import * as tynd from "@tynd/core/client";
 
await tynd.fetch(url);
const ws = new tynd.WebSocket(wsUrl);
const hash = await tynd.crypto.subtle.digest("SHA-256", bytes);
 
await tynd.fs.readText(path);       // Tynd OS API on the same namespace
await tynd.sql.open(dbPath);

Available re-exports: fetch, Request, Response, Headers, AbortController, AbortSignal, ReadableStream, WebSocket, EventSource, crypto, URL, URLSearchParams, TextEncoder, TextDecoder, atob, btoa, Blob, File, FormData, structuredClone, performance.

Behavior matches the Web spec in both runtimes. In lite they point at Tynd’s polyfills; in full they point at Bun’s native implementations.