Gosh

Gosh is a ChromeOS Isolated Web App terminal client for SSH, Mosh, Eternal Terminal, and tsshd. It connects over Chrome’s Direct Sockets API — no browser WebSocket proxy and no companion daemon on the Chromebook.

Features

• SSH, Mosh, Eternal Terminal, and tsshd over Direct Sockets (TCP / UDP)
• Saved hosts and profiles with keys, startup commands, and per-host settings
• Restty terminal with native pane splits, scrollback, themes, and font controls
• Custom caption tabs in an unframed ChromeOS window (ChromeOS Terminal–inspired)
• QUIC or KCP for tsshd UDP mode
• Image paste to the remote host (Kitty graphics–friendly path)
• Optional credential vault for saved passwords (device-locked)
• Light / dark / system chrome and terminal themes

Requirements

• ChromeOS or Chrome 120+ (Chromebook recommended for the full windowing experience)
• Flags below enabled (restart Chrome after changing them)
• A reachable SSH (and optionally Mosh / ET / tsshd) host

Install

1. Enable Chrome flags

Open chrome://flags and set these to Enabled, then restart Chrome:

Flag	Why
#enable-isolated-web-apps	IWA runtime
#enable-isolated-web-app-dev-mode	Required today to install from an update manifest outside enterprise policy
#enable-chromeos-isolated-web-app-set-shape	Rounded unframed window corners
#enable-desktop-pwas-additional-windowing-controls	Minimize / maximize in the custom caption

If Direct Sockets still appear unavailable after install, also enable #enable-direct-sockets-for-isolated-web-apps and restart again.

2. Install from the update manifest

1. Open chrome://web-app-internals

2. Find Install IWA from Update Manifest

3. Paste:

   https://esko.github.io/gosh/update.json
   

4. Launch Gosh from the app launcher (not a normal browser tab)

Landing page with the same URL: esko.github.io/gosh.

3. Updates

Installed copies check the update manifest periodically. You can also use Force update check on chrome://web-app-internals after a new GitHub Release is published.

Quick start after install

1. Open Gosh from the launcher
2. Add a host (user, hostname, protocol) or pick a recent connection
3. Accept the host key prompt on first connect
4. Authenticate with key and/or password when prompted

Development

Contributors: see docs/DEVELOPMENT.md for setup, architecture, and verification.

Local Chromebook install (Dev Mode Proxy or a local .swbn): docs/IWA_DEV_SETUP.md.

Publishing a release to GitHub Pages: docs/RELEASE.md.

npm install
npm run dev          # http://127.0.0.1:5173 — use with Dev Mode Proxy
npm run typecheck
npm run test
npm run build

References

Terminal renderer

Project	Role
Restty (@eslzzyl/restty)	Browser terminal UI — panes, splits, WebGPU/WebGL2; vendored under vendor/restty/
Ghostty (libghostty-vt)	WASM VT / terminal core used inside Restty

SSH / transport WASM and clients

Project	Role
Chromium libapps — nassh, wassh, wasi-js-bindings, ssh_client	Upstream client stack; assets copied into app/upstream/
OpenSSH WASM (ssh.wasm, plus scp.wasm / sftp.wasm / ssh-keygen.wasm)	SSH client (and helpers) run via wassh; from nassh’s plugin build
Mosh (mobile-shell/mosh) — mosh-client.wasm	Predictive remote shell; WASM client shipped with the nassh plugin (app/upstream/plugin/wasm/mosh-client.wasm)
wassh	WASI / WASM host that runs the OpenSSH and Mosh plugins in the browser
Eternal Terminal (MisterTea/EternalTerminal)	Persistent TCP sessions; TypeScript Direct Sockets client in app/src/et/ (protobuf schemas from upstream, not a WASM plugin)
tsshd	UDP SSH relay (KCP/QUIC); browser client compiled to WASM under app/src/tsshd/runtime/

Product / platform

Project	Role
Google Terminal	ChromeOS Terminal UX reference
Isolated Web Apps	Packaging and install model
Direct Sockets	TCP/UDP from the IWA

License

Upstream libapps assets are Chromium-licensed. Restty is MIT. tsshd retains its upstream license. Preserve notices for copied runtime and plugin files.