◈ pi-canvas-design

Infinite design canvas & visual frontend builder for pi. Draw, drag, theme, export — zero dependencies, runs in the browser.

/canvas-design start   → launch on http://localhost:8765
/canvas-design stop    → kill the server
/canvas-design status  → check if running

Install

Install via pi:

pi install pi-canvas-design

Or clone into your pi extensions folder:

cd ~/.pi/extensions
git clone https://github.com/b-iurea/pi-ui-design.git pi-canvas-design

Start: /canvas-design start (opens browser automatically).

What's new in v2.0.0

Complete rewrite of the canvas engine — the tool is now a Figma-like free-form canvas instead of a list-based drag-and-drop builder.

| Feature | Details | |---------|---------| | Infinite canvas | Zoom from 5% to 800%, pan freely with Hand tool or Space+drag | | Draw primitives | Rectangle, Ellipse, Line, Text, Frame — draw directly on canvas | | Tool toolbar | Select (V), Frame (F), Rect (R), Ellipse (O), Line (L), Text (T), Pan (H) | | Smart snapping | Snap to grid + smart edge/center alignment guides (red SVG lines) | | Undo / Redo | Up to 60 steps — Ctrl+Z / Ctrl+Shift+Z | | Clipboard | Cut / Copy / Paste / Duplicate — Ctrl+X/C/V/D | | Minimap | Live thumbnail navigator in the bottom-right corner; click or drag to pan | | Rulers | Pixel rulers along top and left edges, toggle with Shift+R | | Layers panel | Toggle visibility, lock, rename (double-click), delete per element | | Rich Design panel | Fill (color + opacity), Stroke (width, style, position), Effects (drop shadow), Typography, Corner radius, Opacity, Flip H/V, Rotation | | Rotation handle | Drag the circular handle above a selected element; Shift snaps to 15° | | Proportional resize | Hold Shift while dragging a corner handle | | Group | Select 2+ elements → Ctrl+G wraps them in a Frame | | Inline text edit | Double-click a Text primitive to edit content directly on canvas | | Fit / Zoom shortcuts | Shift+1 fit-to-screen · Shift+2 zoom-to-selection · Ctrl+0 100% |

What it does

Build a UI skeleton from a palette of 40+ components — heading, card, navbar, table, hero, modal, pricing, etc. — or draw custom shapes directly. Edit properties, change colors and spacing, then export the result. The tool auto-saves to .ui-design/ in the project root.

The generated code is available in three formats:

• HTML+CSS — standalone page with inline styles
• React JSX — component with style objects
• Tailwind — utility-first classes

The workflow

This tool is half of a two-step process:

1. You draw or drag a rough prototype together in the browser — just structure, placeholder copy, and rough layout. Think of it as sketching a wireframe.
2. The LLM reads it with the read_ui_design tool and treats it as a blueprint — then builds the real, production-quality frontend with full detail, modern design, animations, real content, and responsive layout.

The prototype shows what goes where. The LLM builds what it looks like.

Layout

┌────────────────────────────────────────────────────────────┐
│  Topbar — tools · grid/snap/rulers · undo/redo · zoom      │
├──────────┬─────────────────────────────────┬───────────────┤
│ Components│                                 │ Design / Code │
│ Layers   │  Infinite Canvas                 │  panel        │
│          │  · draw primitives               │               │
│          │  · drag components               │  Fill, Stroke │
│          │  · select, resize, rotate        │  Effects      │
│          │  · smart-snap guides             │  Typography   │
│          │                        ┌──────┐  │  Pos / Size   │
│          │                        │ map  │  │               │
├──────────┴─────────────────────────┴──────┴─┴───────────────┤
│  Bottom bar — save status · element count · cursor position  │
└──────────────────────────────────────────────────────────────┘

Palette (Components tab)

Components are grouped by category: Layout, Typography, Buttons, Forms, Media, Navigation, Cards, Feedback, Data, Sections. Click to add at canvas center, or drag and drop directly onto the canvas.

Layers tab

Lists every element on the canvas. Click to select, double-click to rename, use the eye / lock / ✕ buttons to toggle visibility, lock, or delete.

Tool shortcuts

| Key | Tool | |-----|------| | V | Select | | F | Frame | | R | Rectangle | | O | Ellipse | | L | Line | | T | Text | | H | Hand (pan) | | Space+drag | Pan | | Scroll | Zoom (centered on cursor) | | Escape | Deselect / cancel draw |

Keyboard shortcuts

| Shortcut | Action | |----------|--------| | Ctrl+Z | Undo | | Ctrl+Shift+Z | Redo | | Ctrl+D | Duplicate | | Ctrl+C / X / V | Copy / Cut / Paste | | Ctrl+G | Group selected | | Ctrl+A | Select all | | Delete / Backspace | Delete selected | | Arrow keys | Nudge 1px (Shift = 10px) | | Shift+1 | Fit to screen | | Shift+2 | Zoom to selection | | Ctrl+0 | Reset zoom to 100% | | Ctrl++ / − | Zoom in / out | | Shift+R | Toggle rulers | | Alt+drag | Duplicate and move | | Shift+drag handle | Proportional resize |

Theme

| Control | What it does | |---------|-------------| | Primary | Canvas accent — buttons, badges, progress bars | | Secondary | Canvas secondary accent | | Spacing | Compact / Normal / Spacious | | Radius | None → XL | | Font | Inter, Georgia, Space Grotesk, DM Sans, JetBrains Mono |

Review / Feedback

Every element on the canvas has a 💬 review button (top-left corner, visible on hover). Click it to open a popover where you can type feedback about that specific component — what should change, what looks wrong, what to improve. A Resolved checkbox lets you mark feedback as done.

The same review textarea appears in the Design panel when an element is selected. When multiple elements are selected, the panel shows a single textarea to apply a review to all of them at once.

Reviews are saved to .ui-design/reviews.json and synced between the canvas and the LLM tools automatically every 3 seconds. Elements with active unresolved reviews show an orange 💬 badge so you can spot them at a glance.

API

The plugin registers these tools:

• read_ui_design — reads the prototype from .ui-design/ and returns the HTML + component tree + theme. The tool description (visible to the LLM) explicitly instructs it to treat the prototype as a skeleton/blueprint and build the real frontend from it with full detail, modern design, and proper code.

• ui_list_components — reads the current design tree and returns every component with its id, type, name, position (x/y/w/h), props, and children. Use this to understand the current design before modifying it.

• ui_add_component — adds a new component to the design. Specify type (from the 40+ palette or a primitive: rect, ellipse, line, text, frame), optional props to override defaults, position (x/y), and parent_id for nesting. Returns the new component id.

• ui_update_component — updates an existing component's properties (props), position (x/y), size (w/h), rotation, fill, stroke, effects, or name. Only fields you include change; omitted fields stay as-is.

• ui_remove_component — removes a component and all its children from the design.

• ui_set_theme — updates the design theme: primary, secondary, spacing, radius, font. Only included fields change.

• ui_review_component — adds or updates a review/feedback note on a specific component. Set text to the review content, resolved: true to mark as done. Empty text clears the review. The review shows as an orange 💬 badge on the canvas.

• ui_read_reviews — reads all review notes attached to components. Returns each review with its component name, text, and resolved status. Use this to understand what the user wants changed before updating components.

• build_frontend — saves the LLM-generated production frontend code to .ui-design/generated/ and starts a preview server on port 8766. Opens the browser automatically. Accepts html, optional css, js, and a tailwind flag (auto-injects Tailwind CDN). Pass feedback on iterations to track change history.

• read_feedback — reads the feedback history from .ui-design/generated/feedback.md plus the current generated HTML/CSS/JS. Use during iteration cycles to recall what the user asked for.

Workflows

Production frontend (build → preview → iterate)

flowchart LR
  A[Design prototype in browser] -->|read_ui_design| B[LLM reads skeleton]
  B --> C[LLM generates production frontend]
  C -->|build_frontend| D[Preview server :8766]
  D -->|User reviews in browser| E{Feedback?}
  E -->|Yes| F[User tells LLM changes]
  F -->|read_feedback + build_frontend| D
  E -->|No| G[Done]

1. Sketch — /pi: ui-design start, draw or drag components into a rough layout
2. Generate — ask the LLM to build the real frontend from the prototype

LLM builds via tools

flowchart LR
  A[LLM reads current design] -->|ui_list_components| B[Browser canvas]
  A -->|ui_add_component / ui_update_component| B
  B --> C{Looks good?}
  C -->|No| A
  C -->|Yes| D[build_frontend]
  D --> E[Done]

1. LLM builds — calls ui_add_component, ui_update_component, ui_set_theme to construct or refine the design step by step
2. Iterate — review on canvas, give the LLM feedback
3. Export — call build_frontend to generate the production frontend and preview at localhost:8766

Collaborative design (LLM builds, user reviews per component)

flowchart LR
  A[LLM reads current design] -->|ui_list_components| B[Browser canvas]
  A -->|ui_add_component / ui_update_component| B
  B -->|User adds review via 💬 button| C[reviews.json]
  C -->|ui_read_reviews| A
  A -->|ui_review_component + ui_update_component| B
  B --> D{All reviews resolved?}
  D -->|No| C
  D -->|Yes| A
  A -->|build_frontend| E[Done]

1. LLM builds — calls ui_add_component, ui_update_component, ui_set_theme step by step
2. User reviews — each element has a 💬 button; type feedback directly on the element that needs changing
3. LLM reads — calls ui_read_reviews to see all notes, then ui_review_component to respond/mark resolved
4. Iterate — elements with unresolved reviews keep their orange badge; once all resolved, the design is ready
5. Export — call build_frontend → code saved and served at http://localhost:8766

Commands

| Command | What it does | |---------|-------------| | /pi: ui-design start [port] | Launch the design canvas (default port 8765) | | /pi: ui-design stop | Kill the design canvas server | | /pi: ui-design status | Check if design canvas is running | | /pi: ui-design preview [port] | Start the preview server (default port 8766) | | /pi: ui-design preview-stop | Stop the preview server |

Files

ui-design/
├── index.ts                  # pi plugin entry — server, commands, tools
├── public/
│   ├── index.html            # app shell
│   ├── style.css             # all styles
│   └── app.js                # all logic — no framework, no build
└── .ui-design/               # auto-saved designs (per project)
    ├── current.html           # last generated HTML from canvas
    ├── current-design.json    # full component tree + theme
    └── generated/             # LLM-built production frontend
        ├── index.html         # generated frontend (live preview)
        ├── style.css          # optional CSS
        ├── app.js             # optional JS
        └── feedback.md        # iteration history

Contributing

It's one HTML file, one CSS, one JS, one server. Open public/app.js and go.

Author: biurea