Paint App Prompt System

Modular prompts for testing SpacetimeDB vs PostgreSQL with a collaborative drawing application.

Structure

prompts/
├── README.md
├── features/               # 16 feature building blocks
│   ├── 01_basic.md
│   ├── 02_cursor_indicators.md
│   ├── ...
│   └── 16_keyboard_shortcuts.md
├── composed/               # Pre-built cumulative prompts (language-agnostic)
│   ├── 01_basic.md
│   ├── 02_shapes.md
│   ├── ...
│   └── 12_full.md
├── language/               # Language/backend-specific setup (small files)
│   ├── typescript-spacetime.md
│   ├── typescript-postgres.md
│   ├── rust-spacetime.md
│   └── csharp-spacetime.md
├── grading_rubric.md
└── grading_checklist.md

How to Use

Combine a language file + a composed prompt:

Pick a language: language/rust-spacetime.md
Pick a feature level: composed/12_full.md
Concatenate them (language file first)

Example test command:

bash

# Conceptually: language header + feature prompt
cat language/rust-spacetime.md composed/12_full.md > test_prompt.md

Or when using with an LLM:

@language/rust-spacetime.md @composed/12_full.md execute

Feature Levels

Each level is cumulative — includes all previous features.

Level	Name	New Features Added
01	basic	Basic Drawing, Live Cursors
02	shapes	+ Shapes
03	selection	+ Selection & Manipulation
04	layers	+ Layers with Locking
05	presence	+ Presence & Activity Status
06	comments	+ Comments & Feedback
07	versions	+ Version History
08	permissions	+ Permissions
09	follow	+ Follow Mode
10	activity	+ Activity Feed
11	sharing	+ Private Canvases & Sharing
12	full	+ Canvas Chat, Auto-Cleanup, Text & Stickies, Keyboard Shortcuts

Language Files

File	Stack
`typescript-spacetime.md`	TypeScript + SpacetimeDB (React client)
`typescript-postgres.md`	TypeScript + PostgreSQL (Express + Socket.io)
`rust-spacetime.md`	Rust + SpacetimeDB (axum web GUI)
`csharp-spacetime.md`	C# + SpacetimeDB (MAUI client)

Features Overview

#	Feature	Description	STDB Advantage
1	Basic Drawing	Brush, eraser, colors, real-time sync	Foundation
2	Live Cursors	See others' cursors with tool/color preview	High-frequency updates
3	Shapes	Rectangle, ellipse, line, arrow	Standard feature
4	Selection	Select elements, see others' selections	Real-time sync
5	Layers + Locking	Layers with "locked by user" feature	Instant lock/unlock
6	Presence	Active/idle/away status, current tool	Built-in presence
7	Comments	Pin comments, threads, resolve	Standard feature
8	Version History	Auto-save snapshots, restore	Subscription updates
9	Permissions	Viewer/editor roles, instant enforcement	Row-level security
10	Follow Mode	Follow another user's viewport	Viewport state sync
11	Activity Feed	Real-time action log	Subscription-based
12	Private Canvases	Share links, invite users	Access control
13	Canvas Chat	Chat with collaborators, typing indicator	Real-time messaging
14	Auto-Cleanup	Delete inactive canvases after 30 days	Scheduled reducers
15	Text & Stickies	Text labels, sticky notes, inline editing	Real-time sync
16	Keyboard Shortcuts	Tool shortcuts, delete, escape	UX polish

Why This Structure?

Before (redundant):

composed/
├── typescript/spacetime/12_spacetime_full.md  # Same features
├── typescript/postgres/12_postgres_full.md    # Same features
├── rust/spacetime/12_spacetime_full.md        # Same features
├── csharp/spacetime/12_spacetime_full.md      # Same features

After (DRY):

composed/12_full.md           # Features (one source of truth)
language/rust-spacetime.md    # Just setup/architecture (~30 lines)

Benefits:

Update features once → applies to all languages
Language files are tiny - just setup and constraints
Easy to add new languages (one small file)