Simple

You describe your app. Claude builds it. Postgres runs it.

Simple is a full-stack template designed for building apps with AI. You tell Claude what you want, watch the domain model take shape in real time, then let Claude implement the whole thing — schema, server functions, UI components, tests. You review and use the running app.

Get started

bun create blueshed/simple my-app
cd my-app
bun run up    # start postgres + model server
bun run dev   # start app server

bun create copies the template, installs dependencies, and prompts you for your app and database name.

Build your app

Open Claude Code in your project directory. That's your workspace — you talk, Claude builds.

1. Model your domain — tell Claude /model-app and describe what you're building:

/model-app todo with tags and tasks of pending, active or done

Claude creates stories, entities, documents, and methods. While you talk, browse http://localhost:8080 to see the domain model update in real time — entity diagrams, document graphs, and implementation checklists.

2. Export the spec — when the model looks right:

bun model export > spec.md

3. Implement — tell Claude /implement. It reads spec.md and builds the full app: database schema, SQL functions, TypeScript components, seed data. The dev server is already running — open your browser and use what Claude just built.

4. Iterate — found something to change? Go back to /model-app, update the model, re-export, and /implement again. Or just ask Claude to make changes directly.

How it works

Simple follows one pattern: postgres owns everything, the server routes, the client merges.

• Postgres is the application — schema, permissions, business logic, and real-time notifications all live in SQL functions
• Server is a relay — verifies tokens, calls functions, fans out change notifications over WebSocket
• Client merges deltas — open a document, get live updates via pg_notify, no polling or re-fetching

Client                    Server                  Postgres
  │                          │                       │
  │  POST /auth login(...)   │                       │
  │─────────────────────────→│  SELECT login(...)    │
  │                          │──────────────────────→│
  │  { token, profile }      │                       │
  │←─────────────────────────│                       │
  │                          │                       │
  │  WS open thing_doc(1)    │                       │
  │─────────────────────────→│  subscribe            │
  │                          │                       │
  │  api.save_thing(...)     │  SELECT save_thing()  │
  │─────────────────────────→│──────────────────────→│── permission check
  │  { ok, data: id }        │                       │── mutate
  │←─────────────────────────│                       │── pg_notify
  │                          │← LISTEN 'change'      │
  │  { type:"notify", data } │── fan out to docs     │
  │←─────────────────────────│                       │

Learn more

Detailed reference for when you're deeper in:

• Server — WebSocket protocol, fan-out, guards
• Client — session, signals, doc subscriptions, merging
• Database — SQL conventions, notify payload, save/remove pattern
• CSS — token system, theming, component conventions
• Testing — unit and integration test patterns
• Easy — the domain modeling tool behind /model-app