Terminal & web preview

Two Tier-2 features that keep you in the editor: a real interactive terminal and an in-app web preview for dev servers. Both need the Termux setup done (the terminal in particular needs ttyd, which the one-tap toolchain install includes).

Embedded terminal

A full interactive terminal, running inside Calypso with a native Flutter terminal view connected to a Termux shell. Unlike streamed runs, it has real stdin, Ctrl-C, colours and scrollback — so REPLs, prompts, git rebase -i, and watching a server’s live logs all work.

Open it from Run menu → Open Terminal (or the Command Palette).

• Tablets / wide screens: it docks in the bottom panel next to Output — tap between the Output and Terminal tabs. Drag the handle at the top to resize.
• Phones: it opens full-screen.

The terminal starts in your active project’s folder, and the session persists — close and reopen it and you reconnect to the same shell. Opening the terminal for a different project folder starts a fresh session there.

To clear the screen, type clear (just like any shell).

Manual npm commands

Calypso’s New Project flow works around Android/Termux command quirks for you. Some raw terminal shortcuts, such as npm create vite@latest, may still fail in Termux because npm package command shims are not always available when bin-links are disabled. If that happens, use New Project for scaffolding, or run the local tool directly with node node_modules/....

Phone vs tablet

On a phone, Run Active File in Termux and Run Command in Termux are usually the faster path — they do most of what the terminal does, with bigger text and no on-screen-keyboard fiddliness. The embedded terminal shines on a tablet or with a hardware keyboard, where interactivity is comfortable.

Web preview

Started a dev server in the terminal — say an Express app on localhost:3000? Run menu → Open Web Preview opens it inside Calypso, so you don’t have to switch to a browser.

• An address bar lets you type any URL (it defaults to http://localhost:3000 and remembers your last one). The http:// is added for you.
• Reload (↻) after you change code; a progress bar shows loads.
• It reaches your Termux dev server directly — Android shares localhost across apps, so no extra setup is needed.

A typical loop:

# in the Terminal
npm install express
node server.js      # "Server running on port 3000"

Then Open Web Preview → localhost:3000 renders in-app. Edit, save, restart the server in the terminal, tap Reload.

Note

If the preview shows connection refused, the server isn’t running yet — start it in the terminal first, then reload.