VANTHRAX ROLE PLAY SYSTEMS

Your characters. Your stories. Your AI.

VANTHRAX is a free, private AI roleplay and character chat app that runs in your browser. No account, no subscription, and no server holding your conversations.

Bring your own AI

Connect OpenRouter, NanoGPT or any OpenAI-compatible endpoint (including local servers such as LM Studio, llama.cpp or Ollama) with your own API key. You pay the provider directly; requests go straight from your device to them. Keys can stay for the current session only or be encrypted on your device with a passphrase.

Your characters, imported or created

Import SillyTavern-compatible Character Card V1, V2 and V3 files in JSON or PNG format, including embedded lorebooks, or create characters from scratch. Export them again at any time.

Built for roleplay

  • Streaming replies, regenerate and swipe between alternative responses
  • Edit, branch and delete messages; alternate greetings
  • Personas for the characters you play
  • Keyword-activated lorebooks for world details
  • A prompt preview that shows exactly what is sent

Private and local-first

Characters, chats, personas, lorebooks and settings are stored on your device. Export a backup whenever you like. There are no accounts, analytics or tracking.

Works everywhere

Use VANTHRAX on iPhone, Android, tablets and desktop browsers. Install it to your Home Screen for a full-screen app that opens instantly and lets you browse your library offline.

Open VANTHRAX