nose-pluto/CLAUDE.md

---
description: NOSE Pluto - A Commodore 64-inspired web terminal with Bun-based shell
globs: "*.ts, *.tsx, *.html, *.css, *.js, *.jsx, package.json"
alwaysApply: true
---

# NOSE Pluto

NOSE Pluto is a web-based terminal inspired by the Commodore 64, running on a Bun-based shell server. It hosts Val Town-style web apps for your home network, runs custom commands written in TypeScript, and lives on a Raspberry Pi 5.

## Architecture Overview

- **Server**: Bun + Hono serving a C64-inspired terminal over WebSockets
- **Client**: Browser-based terminal UI with virtual 960×540 (16:9) screen that scales
- **Commands**: TypeScript files that run on the server and return output to the client
- **Projects**: Multi-project system with isolated commands, webapps, and state
- **Webapps**: Subdomain-based apps (e.g., `myapp.nose-pluto.local`)
- **Games**: PICO-8-style game engine with `init()`, `update()`, `draw()` API
- **Session**: AsyncLocalStorage-based session management (1 browser tab = 1 session)

## Technology Stack

Use Bun exclusively instead of Node.js:

- `bun <file>` instead of `node <file>` or `ts-node <file>`
- `bun test` instead of `jest` or `vitest`
- `bun build <file.html|file.ts|file.css>` instead of `webpack` or `esbuild`
- `bun install` instead of `npm install` or `yarn install` or `pnpm install`
- `bun run <script>` instead of `npm run <script>`
- Bun automatically loads .env, so don't use dotenv

### Bun APIs

- `Bun.serve()` supports WebSockets, HTTPS, and routes (don't use `express`)
- `bun:sqlite` for SQLite (don't use `better-sqlite3`)
- `Bun.redis` for Redis (don't use `ioredis`)
- `Bun.sql` for Postgres (don't use `pg` or `postgres.js`)
- `WebSocket` is built-in (don't use `ws`)
- Prefer `Bun.file` over `node:fs`'s readFile/writeFile
- `Bun.$\`ls\`` instead of execa

## Key Concepts

### Commands

Commands are TypeScript files in `bin/` directories that export a `default` function:

```ts
// bin/hello.ts
export default async function (name: string): Promise<string> {
  return `Hello, ${name}!`
}
```

Commands can return:
- `string` - plain text output
- `{ text: string, script?: string }` - text with optional client-side JS
- `{ html: string, script?: string }` - HTML with optional client-side JS
- `{ script: string }` - client-side JS only
- `{ error: string }` - error message
- `{ game: string }` - launch a game

Commands can also `throw` to display an error.

**Command Locations** (searched in order):
1. `~/nose/<project>/bin/` - project-specific commands
2. `~/nose/root/bin/` - global user commands (NOSE_ROOT_BIN)
3. `./bin/` - built-in system commands (NOSE_BIN)

**Documentation**: Commands use `//` comments at the top of the file for inline help:

```ts
// This command does something cool.
// Usage: mycmd <arg1> <arg2>

export default async function (arg1: string, arg2: string) {
  // ...
}
```

Use `/// <reference lib="dom" />` on the first line to mark commands that run in the browser.

### Projects

Projects live in `~/nose/<project-name>/` and have:
- `bin/` - project-specific commands
- `index.ts` or `index.tsx` - webapp entry point (optional)
- `pub/` - static files served at subdomain (optional)

The `root` project is special - it's the default project and its `bin/` contains global commands.

**Project Structure**:
```
~/nose/
  root/           # default project
    bin/          # global commands
  myproject/      # custom project
    bin/          # project commands
    index.ts      # webapp (served at myproject.nose-pluto.local)
    pub/          # static files
```

### Webapps

Webapps are served on subdomains (e.g., `myapp.nose-pluto.local`). They can:
- Export a `default` Hono app for dynamic routes
- Export a `default` function that returns a Response, string, or JSX
- Serve static files from `pub/` directory

```ts
// ~/nose/myapp/index.ts
import { Hono } from "hono"

const app = new Hono()

app.get("/", c => c.text("Hello from myapp!"))

export default app
```

Static files in `pub/` are served automatically (e.g., `pub/index.html` → `myapp.nose-pluto.local/`).

### Games

Games are commands with `export const game = true` and three exports:

```ts
/// <reference lib="dom" />
export const game = true

import type { GameContext, InputState } from "@/shared/game"

export function init() {
  // Initialize game state
}

export function update(delta: number, input: InputState) {
  // Update game logic (60 FPS)
}

export function draw(game: GameContext) {
  // Draw to 960×540 canvas
  game.clear()
  game.rectfill(0, 0, 100, 100, "red")
  game.text("Score: 0", 10, 10, "white")
}
```

**GameContext API**: `clear()`, `text()`, `centerText()`, `rect()`, `rectfill()`, `circ()`, `circfill()`, `line()`, `oval()`, `ovalfill()`, `rrect()`, `rrectfill()`, `trianglefill()`, `polygonfill()`

**InputState**: Tracks keyboard/gamepad with `pressed`, `prevPressed`, `justPressed`, `justReleased` Sets.

### Session Management

Sessions use AsyncLocalStorage for context isolation:

```ts
import { sessionGet, sessionSet } from "@/session"

// Get session data
const project = sessionGet("project")
const cwd = sessionGet("cwd")

// Set session data (auto-syncs to client)
sessionSet("project", "myproject")
sessionSet("cwd", "/some/path")
```

Session keys: `sessionId`, `taskId`, `project`, `cwd`, `ws`

## File Structure

```
src/
  server.tsx           # Main Hono server
  websocket.ts         # WebSocket connection management
  dispatch.ts          # Client→server message router
  shell.ts             # Command execution (server-side)
  commands.ts          # Command discovery and loading
  session.ts           # Session management (AsyncLocalStorage)
  project.ts           # Project helpers
  webapp.ts            # Webapp hosting
  state.ts             # Persistent state storage
  config.ts            # Environment configuration

  html/
    layout.tsx         # Base HTML layout
    terminal.tsx       # Terminal UI components

  js/
    main.ts            # Client entry point
    websocket.ts       # WebSocket client
    shell.ts           # Command execution (client-side)
    scrollback.ts      # Terminal scrollback buffer
    input.ts           # Input handling
    completion.ts      # Tab completion
    history.ts         # Command history
    editor.ts          # File editor
    game.ts            # Game engine client
    browser.ts         # Embedded browser

  shared/
    types.ts           # Shared TypeScript types
    game.ts            # Game engine types and context
    utils.ts           # Shared utilities

bin/                   # Built-in commands
public/                # Static assets (CSS, fonts, images)
```

## Development Workflow

```bash
# Local development with hot reload
bun dev

# Production mode (no DNS)
bun prod-nodns

# Production mode (with DNS)
bun prod

# Type checking
bun check

# Deploy to Raspberry Pi
bun deploy
```

**Environment Variables**:
- `NOSE_DIR` - Directory for projects (default: `~/nose`)
- `NODE_ENV` - Set to `production` for production mode
- `NO_DNS` - Disable DNS features in production
- `BUN_HOT` - Enable hot reload (set by `bun dev`)

## Important Patterns

### Path Aliases

Use `@/` for imports from `src/` when writing commands:

```ts
import { sessionGet } from "@/session"
import { commands } from "@/commands"
import type { Message } from "@/shared/types"
```

### Command Patterns

**Simple text command**:
```ts
export default function () {
  return "Hello, world!"
}
```

**HTML output**:
```ts
export default function () {
  return { html: "<h1>Hello</h1>" }
}
```

**JSX output** (auto-converted):
```tsx
export default function () {
  return <h1>Hello</h1>
}
```

**Client-side script**:
```ts
export default function () {
  return {
    text: "Running script...",
    script: "alert('Hello from browser!')"
  }
}
```

### WebSocket Messages

Messages between client and server use typed message objects:

```ts
// Client → Server
{ type: "input", id: "abc123", session: "0", data: "ls" }
{ type: "save-file", id: "/path/to/file", session: "0", data: "content" }
{ type: "session:update", data: { project: "myproject" } }

// Server → Client
{ type: "output", id: "abc123", data: { status: "ok", output: "result" } }
{ type: "commands", data: ["ls", "cd", "help"] }
{ type: "apps", data: ["myapp", "otherapp"] }
{ type: "game:start", id: "abc123", data: "snake" }
{ type: "session:start", data: { NOSE_DIR, project, cwd, mode, hostname } }
```

## Testing

Use `bun test`:

```ts
import { test, expect } from "bun:test"

test("command output", () => {
  expect(1).toBe(1)
})
```

## Notes

- Virtual screen size is fixed at 960×540 (16:9) in "cinema" mode and scales to fit the display
- Virtual screen size is fixed at 960x100%vh in "tall" mode and scales to fit the display
- Font: C64 Pro Mono (see `public/vendor/`)
- Commands are hot-reloaded when files change
- WebSocket connections are managed per-session (1 tab = 1 session)
- Session state persists across reconnects
- The `help` command extracts documentation from `//` comments in commands