Refactor into multi-template monorepo with Next.js support

Restructure project to support multiple templates via Nix flakes and omnix.
Users can now choose between vanilla JavaScript or Next.js TypeScript
templates during initialization.

- Move existing template to templates/vanilla/
- Add templates/nextjs/ with App Router, TypeScript, and React 19
- Update flake.nix for multi-template outputs
- Add TypeScript support to shared devshell
- Preserve FHS compatibility for both templates
- Update README with comprehensive template comparison and usage

.gitignore

@@ -4,6 +4,12 @@ node_modules/
 # Build output
 dist/
 build/
+.next/
+out/
+
+# TypeScript
+*.tsbuildinfo
+next-env.d.ts
 
 # Direnv
 .direnv/

README.md

@@ -1,29 +1,82 @@
-# JavaScript Template
+# JavaScript Templates
 
-A minimal JavaScript development template using Nix. Key features:
+A family of minimal JavaScript development templates using Nix for reproducible
+environments. Choose the right foundation for your project while maintaining
+consistent tooling and workflows.
 
-- Nix + Flakes for reproducible environments
-- Bun (fast JavaScript runtime & package manager)
-- Vite (development server & build tool)
-- Node.js (mature REPL with custom helpers)
-- ESLint + Prettier (linting & formatting)
-- Devshell commands via just
+## Available Templates
 
-## Prerequisites
+### Vanilla
+
+Minimal JavaScript template for interactive sites and applications.
+
+**Best for:**
+
+- Interactive tools and utilities
+- Client-side games
+- Dashboards and data visualizations
+- Projects that don't need a framework
+
+**Tech stack:**
+
+- Vite (development server & bundler)
+- Vanilla JavaScript (no framework)
+- Node.js REPL with custom helpers
+
+### Next.js
+
+TypeScript template with App Router for modern web applications.
+
+**Best for:**
+
+- Full-stack applications (e-commerce, SaaS)
+- Static sites with growth potential
+- Projects needing API routes
+- Server-side rendering or static generation
+
+**Tech stack:**
+
+- Next.js 15 with App Router
+- React 19
+- TypeScript
+- Optimized for Vercel deployment
+
+## Shared Foundation
+
+All templates include:
+
+- **Nix + Flakes** - reproducible development environments
+- **Bun** - fast JavaScript runtime & package manager
+- **ESLint + Prettier** - code quality and formatting
+- **just** - consistent command-line interface
+- **FHS compatibility** - toggle for NixOS edge cases
+
+## Getting Started
+
+### Prerequisites
 
 - [Nix](https://nixos.org/download.html) with flakes enabled
 - [direnv](https://direnv.net/) (optional but recommended)
 
-## Getting Started
+### Initialize a Project
 
-Initialize a new project using [omnix](https://omnix.page):
+Using [omnix](https://omnix.page):
+
+**Vanilla template:**
 
 ```sh
 nix run nixpkgs#omnix -- \
-  init github:sajenim/javascript-template -o ./my-project
+  init github:sajenim/javascript-templates -o ./my-project
 ```
 
-Then enter the development environment:
+**Next.js template:**
+
+```sh
+nix run nixpkgs#omnix -- \
+  init github:sajenim/javascript-templates#nextjs -o ./my-nextjs-app
+```
+
+### Enter Development Environment
 
 ```sh
 cd my-project
@@ -31,37 +84,106 @@ direnv allow  # Or use: nix develop
 just dev
 ```
 
-**NixOS users:** If bun-installed binaries fail to find system libraries, enable FHS compatibility:
+### NixOS FHS Compatibility
+
+If bun-installed binaries fail to find system libraries, enable FHS
+compatibility:
 
 ```nix
 # nix/modules/devshell.nix
 fhs = true;
 ```
 
-## Available Commands
+## Common Commands
 
-Run `just` to see all available commands:
+Both templates share the same command interface:
 
 ```sh
-just dev       # Start dev server
-just repl      # Node.js REPL with helpers
-just lint      # Lint with ESLint
-just format    # Format with Prettier
+just           # List all available commands
+just dev       # Start development server
 just build     # Production build
+just lint      # Lint code
+just format    # Format code
 just clean     # Clean build artifacts
-just update    # Update flake inputs
-just upgrade   # Upgrade bun packages
+just update    # Update Nix flake inputs
+just upgrade   # Upgrade package dependencies
 ```
 
+### Template-Specific Commands
+
+**Vanilla:**
+
+```sh
+just repl      # Node.js REPL with custom helpers
+just preview   # Preview production build
+```
+
+**Next.js:**
+
+```sh
+just start     # Start production server
+just typecheck # TypeScript type checking
+just check     # Run format-check, lint, and typecheck
+```
+
+## Next.js Static Export
+
+For pure static sites (no server-side features), enable static export:
+
+```js
+// templates/nextjs/next.config.js
+const nextConfig = {
+  output: 'export',
+  // ...
+};
+```
+
+Note: This disables API routes and server-side rendering.
+
 ## Customization
 
-This template provides minimal, sensible defaults. Customize as needed:
+All templates provide minimal, sensible defaults. Customize as needed:
+
+**Vanilla:**
 
 - Modify linting rules in `eslint.config.js`
+- Add custom REPL helpers in `.replrc.js`
+- Extend Vite config if needed
+
+**Next.js:**
+
+- Configure Next.js in `next.config.js`
+- Customize ESLint rules in `.eslintrc.json`
+- Adjust TypeScript settings in `tsconfig.json`
+- Extend ESLint config for stricter rules
+
+**Both templates:**
+
 - Add Prettier config via `.prettierrc` if needed
 - Extend `Justfile` with project-specific commands
-- Add custom REPL helpers in `.replrc.js`
+- Adjust Nix devshell in `nix/modules/devshell.nix`
+
+## Template Comparison
+
+| Feature            | Vanilla | Next.js |
+| ------------------ | ------- | ------- |
+| Framework          | None    | Next.js |
+| Language           | JS      | TS      |
+| Bundler            | Vite    | Next.js |
+| Client-side only   | ✓       | ✗       |
+| Server-side API    | ✗       | ✓       |
+| Static generation  | ✓       | ✓       |
+| Type checking      | ✗       | ✓       |
+| React components   | ✗       | ✓       |
+| File-based routing | ✗       | ✓       |
 
 ## Acknowledgments
 
-- [srid's haskell-template](https://github.com/srid/haskell-template)
+- [srid's haskell-template](https://github.com/srid/haskell-template) -
+  inspiration for Nix flakes structure
+- [Next.js](https://nextjs.org/) - React framework for production
+- [Bun](https://bun.sh/) - fast JavaScript runtime
+
+## License
+
+MIT

flake.nix

@@ -1,5 +1,5 @@
 {
-  description = "Nix template for JavaScript projects, powered by Bun";
+  description = "Nix templates for JavaScript projects, powered by Bun";
 
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixos-24.11";

nix/modules/devshell.nix

@@ -22,6 +22,7 @@ in {
         [
           bun
           nodejs
+          typescript
           eslint
           just
           prettierd

nix/modules/template.nix

@@ -1,19 +1,41 @@
-{inputs, ...}: {
+{inputs, ...}: let
+  root = inputs.self;
+in {
   flake = rec {
-    templates.default = {
-      description = "A minimal JavaScript project template with Bun and Nix";
-      path = inputs.self;
+    templates = {
+      default = {
+        description = "Minimal JavaScript template with Vite and Bun";
+        path = "${root}/templates/vanilla";
       };
 
-    om.templates.javascript-template = {
+      nextjs = {
+        description = "Next.js TypeScript template with App Router for Vercel";
+        path = "${root}/templates/nextjs";
+      };
+    };
+
+    om.templates = {
+      javascript-vanilla = {
         template = templates.default;
         params = [
           {
             name = "package-name";
             description = "Name of the JavaScript package";
-          placeholder = "javascript-template";
+            placeholder = "my-project";
+          }
+        ];
+      };
+
+      javascript-nextjs = {
+        template = templates.nextjs;
+        params = [
+          {
+            name = "package-name";
+            description = "Name of the Next.js project";
+            placeholder = "my-nextjs-app";
           }
         ];
       };
     };
+  };
 }

templates/nextjs/.eslintrc.json

@@ -0,0 +1,3 @@
+{
+  "extends": ["next/core-web-vitals", "next/typescript"]
+}

templates/nextjs/.prettierignore

@@ -0,0 +1,3 @@
+.next
+node_modules
+bun.lockb

templates/nextjs/Justfile

@@ -0,0 +1,66 @@
+# List available commands
+default:
+    @just --list
+
+# Start development server with hot reload
+dev:
+    bun run dev
+
+# Add a package dependency
+add package:
+    bun add {{package}}
+
+# Add a dev dependency
+add-dev package:
+    bun add -d {{package}}
+
+# Remove a package dependency
+remove package:
+    bun remove {{package}}
+
+# Build for production
+build:
+    bun run build
+
+# Start production server
+start:
+    bun run start
+
+# Install dependencies
+install:
+    bun install
+
+# Update flake inputs
+update:
+    nix flake update
+
+# Upgrade package dependencies
+upgrade:
+    bun update
+
+# Clean build artifacts and dependencies
+clean:
+    rm -rf .next node_modules bun.lockb
+
+# Format code with prettierd
+format:
+    prettierd --write .
+
+# Check formatting without making changes
+format-check:
+    prettierd --check .
+
+# Lint code with Next.js ESLint
+lint:
+    bun run lint
+
+# Lint and auto-fix issues
+lint-fix:
+    bun run lint -- --fix
+
+# Type check with TypeScript
+typecheck:
+    tsc --noEmit
+
+# Check formatting, linting, and types
+check: format-check lint typecheck

templates/nextjs/app/globals.css

@@ -0,0 +1,64 @@
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+}
+
+body {
+  font-family: system-ui, -apple-system, sans-serif;
+  line-height: 1.6;
+  padding: 2rem;
+  background: #f5f5f5;
+  color: #333;
+}
+
+main {
+  max-width: 800px;
+  margin: 0 auto;
+  padding: 2rem;
+  background: white;
+  border-radius: 8px;
+  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
+}
+
+h1 {
+  margin-bottom: 1rem;
+  color: #2c3e50;
+}
+
+p {
+  margin-bottom: 1.5rem;
+}
+
+code {
+  padding: 0.2em 0.4em;
+  background: #f0f0f0;
+  border-radius: 3px;
+  font-family: 'Monaco', 'Courier New', monospace;
+  font-size: 0.9em;
+}
+
+.container {
+  display: flex;
+  flex-direction: column;
+  gap: 1.5rem;
+}
+
+.links {
+  display: flex;
+  gap: 1rem;
+  flex-wrap: wrap;
+}
+
+.links a {
+  padding: 0.5rem 1rem;
+  background: #2c3e50;
+  color: white;
+  text-decoration: none;
+  border-radius: 4px;
+  transition: background 0.2s;
+}
+
+.links a:hover {
+  background: #34495e;
+}

templates/nextjs/app/layout.tsx

@@ -0,0 +1,19 @@
+import type { Metadata } from 'next';
+import './globals.css';
+
+export const metadata: Metadata = {
+  title: '{{package-name}}',
+  description: 'A Next.js application built with Bun and Nix',
+};
+
+export default function RootLayout({
+  children,
+}: Readonly<{
+  children: React.ReactNode;
+}>) {
+  return (
+    <html lang="en">
+      <body>{children}</body>
+    </html>
+  );
+}

templates/nextjs/app/page.tsx

@@ -0,0 +1,37 @@
+export default function Home() {
+  return (
+    <main>
+      <div className="container">
+        <h1>Welcome to {{package-name}}</h1>
+        <p>
+          A minimal Next.js TypeScript template with App Router, powered by
+          Bun and Nix.
+        </p>
+
+        <div className="links">
+          <a
+            href="https://nextjs.org/docs"
+            target="_blank"
+            rel="noopener noreferrer"
+          >
+            Next.js Docs
+          </a>
+          <a
+            href="https://react.dev"
+            target="_blank"
+            rel="noopener noreferrer"
+          >
+            React Docs
+          </a>
+          <a
+            href="https://www.typescriptlang.org/docs"
+            target="_blank"
+            rel="noopener noreferrer"
+          >
+            TypeScript Docs
+          </a>
+        </div>
+      </div>
+    </main>
+  );
+}

templates/nextjs/next.config.js

@@ -0,0 +1,17 @@
+/** @type {import('next').NextConfig} */
+const nextConfig = {
+  // Uncomment for pure static export (Vercel will auto-detect this)
+  // output: 'export',
+
+  // Recommended for static sites
+  reactStrictMode: true,
+
+  // Optional: Disable server-side logging in production
+  // logging: {
+  //   fetches: {
+  //     fullUrl: true,
+  //   },
+  // },
+};
+
+export default nextConfig;

templates/nextjs/package.json

@@ -0,0 +1,25 @@
+{
+  "name": "{{package-name}}",
+  "type": "module",
+  "version": "1.0.0",
+  "private": true,
+  "scripts": {
+    "dev": "next dev",
+    "build": "next build",
+    "start": "next start",
+    "lint": "next lint"
+  },
+  "dependencies": {
+    "next": "^15.0.0",
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0"
+  },
+  "devDependencies": {
+    "@types/node": "^22.0.0",
+    "@types/react": "^19.0.0",
+    "@types/react-dom": "^19.0.0",
+    "eslint": "^9.0.0",
+    "eslint-config-next": "^15.0.0",
+    "typescript": "^5.6.0"
+  }
+}

templates/nextjs/tsconfig.json

@@ -0,0 +1,27 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "lib": ["dom", "dom.iterable", "esnext"],
+    "allowJs": true,
+    "skipLibCheck": true,
+    "strict": true,
+    "noEmit": true,
+    "esModuleInterop": true,
+    "module": "esnext",
+    "moduleResolution": "bundler",
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "jsx": "preserve",
+    "incremental": true,
+    "plugins": [
+      {
+        "name": "next"
+      }
+    ],
+    "paths": {
+      "@/*": ["./*"]
+    }
+  },
+  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
+  "exclude": ["node_modules"]
+}