Conlang

Build constructed languages with instant feedback.

A modern web app for creating, testing, and sharing conlangs (constructed languages). Define sounds, build vocabulary, generate words deterministically, and see your language come to life.

Live Demo →

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Why Conlang?

Creating a constructed language is complex. You need to define phonology, build vocabulary, ensure consistency, and test how it sounds. Conlang makes this process interactive and immediate:

• Start instantly — No signup required. Your work saves locally.
• Generate words — Seeded randomization means reproducible results.
• Test phrases — See how your language handles real sentences.
• Share publicly — Get a unique URL to share your creation.

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Features

Sound System

• Phonology — Define consonants and vowels with presets (Elvish, Harsh, Japanese-like, etc.)
• Phonotactics — Weighted syllable templates (CV, CVC, CVCC) and forbidden sequences
• Orthography — Map phonemes to written forms with digraph support
• Phonological Rules — Context-sensitive sound changes

Vocabulary

• Word Generator — Generate words matching your sound rules
• Lexicon — Full vocabulary management with search, tags, and notes
• Name Generator — Create person names, place names, and faction names
• Sample Phrases — Test with phrase packs (Everyday, Fantasy, Sci-Fi)

Writing & Style

• Custom Scripts — Draw glyphs or use AI to clean up sketches
• Style Controls — Preferred/avoided sounds, common endings
• Script Preview — See text rendered in your custom writing system

Grammar

• Morphology — Prefixes, suffixes, infixes, and circumfixes
• Syntax — Word order (SVO/SOV/etc.), adjective position, adpositions
• Text Generator — Transform structured glosses into conlang sentences

Collaboration

• Public Sharing — Share languages via unique URLs
• Version History — Snapshot and restore previous versions
• Preset Marketplace — Share and download community presets
• Community Phrases — User-contributed phrase packs

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Quick Start

Try it Online

Visit conlang.app — no installation needed.

Run Locally

# Clone the repo
git clone https://github.com/coreyhaines31/conlang.git
cd conlang

# Install dependencies
npm install

# Set up environment (see Configuration below)
cp .env.example .env.local

# Run development server
npm run dev

Open http://localhost:3001

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Configuration

Environment Variables

Copy .env.example to .env.local and fill it in:

Variable	Required	Purpose
DATABASE_URL	Yes	Postgres connection string (Neon works well)
BETTER_AUTH_SECRET	Yes	Session signing secret (openssl rand -base64 32)
BETTER_AUTH_URL	Yes	App URL, http://localhost:3001 locally
RESEND_API_KEY	Yes	Sends magic-link sign-in emails via Resend
SUPPORT_EMAIL	Yes	Inbox for the in-app support form
CRON_SECRET	No	Protects /api/cron/keep-alive
NEXT_PUBLIC_SENTRY_DSN	No	Client error reporting
AI_GATEWAY_API_KEY	No	Vercel AI Gateway key for AI glyph generation and e2e AI steps (not needed on Vercel, which uses OIDC)
GLYPH_MODEL	No	Override the glyph model with any vision-capable AI Gateway model ID

Signed-out visitors keep languages as local drafts in the browser, so you can explore most of the editor before setting up email.

Database Setup

The schema lives in src/lib/db/schema.ts (Drizzle). Push it to an empty database:

export DATABASE_URL=postgres://...
npx drizzle-kit push

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Tech Stack

Layer	Technology
Framework	Next.js 16 (App Router)
Language	TypeScript
Styling	Tailwind CSS v4
Components	shadcn/ui + Lucide Icons
Database	Neon Postgres + Drizzle ORM
Auth	Better Auth (magic links via Resend)
AI	Vercel AI Gateway + AI SDK (optional, glyph generation)
Testing	Vitest, e2e
Hosting	Vercel

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Project Structure

src/
├── app/
│   ├── page.tsx                 # Main editor
│   ├── actions.ts               # Server actions (DB operations)
│   ├── api/auth/[...all]/       # Better Auth handler
│   ├── api/glyph/route.ts       # AI glyph generation
│   └── l/[slug]/page.tsx        # Public language view
├── components/
│   ├── LanguageEditor.tsx       # Main editor shell
│   ├── EditorNavigation.tsx     # Sidebar navigation
│   ├── GlyphCanvas.tsx          # Drawing canvas for glyphs
│   ├── tabs/                    # Feature tabs
│   │   ├── OverviewTab.tsx      # Word generation
│   │   ├── PhonologyTab.tsx     # Consonants/vowels
│   │   ├── PhonotacticsTab.tsx  # Syllable structure
│   │   ├── OrthographyTab.tsx   # Spelling rules
│   │   ├── LexiconTab.tsx       # Vocabulary
│   │   ├── ScriptTab.tsx        # Custom writing system
│   │   ├── MorphologyTab.tsx    # Grammar
│   │   └── ...
│   └── ui/                      # shadcn/ui components
└── lib/
    ├── generator.ts             # Seeded word generation
    ├── morphology.ts            # Affix system
    ├── script.ts                # Writing system utilities
    ├── textGenerator.ts         # Gloss → conlang
    ├── auth.ts                  # Better Auth config
    └── db/                      # Drizzle client & schema
tests/                           # e2e browser tests

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Database Schema

languages

Core language definitions with JSON configuration.

Column	Type	Description
id	UUID	Primary key
user_id	UUID	Owner
name	TEXT	Language name
slug	TEXT	URL-safe identifier
is_public	BOOLEAN	Visibility
seed	BIGINT	RNG seed for determinism
definition	JSONB	Full configuration

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