Sky Playground ☁

An interactive browser-based playground for the Sky language — built entirely in Sky itself, using Sky.Live and Std.Ui.

Requirements

• sky compiler on $PATH
• Go 1.21+

Running locally

git clone <this-repo>
cd sky-playground
sky run

Then open http://localhost:8080 in your browser.

Features

• 6 built-in examples covering core Sky patterns

• Format — runs sky fmt on your code and replaces the editor content

• Run — runs sky build && ./sky-out/app in a sandboxed temp directory, streams output back

• Security sandbox — the following modules are blocked in the playground (detected client-side and stripped server-side before any build attempt):

  Blocked module	Reason
  File, Io	File-system access
  Process	Arbitrary subprocess execution
  System	Environment / exit / CWD access
  Db, Auth	Database and authentication
  Http	Outbound network requests (SSRF)
  Server, Live	Spawning nested servers
  RateLimit, Middleware	HTTP infrastructure
  Ffi, Context, Fmt	Low-level / Go FFI escape hatches

  Allowed: String, List, Dict, Set, Maybe, Result, Math, Regex, Char, Crypto (hashing only), Encoding, Json, Uuid, Task, Time, Random, Log.println.

Architecture

src/
├── Main.sky          — Sky.Live app entry (init, subscriptions, main)
├── State.sky         — Model + Msg types (no Std.Ui imports)
├── Update.sky        — update function + Cmd.perform wiring
├── Security.sky      — pure security validation and sanitisation
├── Runner.sky        — Task helpers: format and run via Process
├── Examples.sky      — built-in example programs
└── View/
    ├── Common.sky    — shared colours, spacing constants, button helpers
    ├── Sidebar.sky   — examples list panel
    ├── Editor.sky    — code input + Format / Run buttons
    └── Output.sky    — output display panel