Hidden Door

Chat with millions of user-made AI characters.

A consumer platform for creating and chatting with AI personas — fictional characters, helpers, and roleplay companions — across web and mobile. Hosts millions of community-built characters with voice calls and image generation on the paid tier. One of the largest conversational-AI roleplay products by usage.

Conversational AI characters and NPCs for games and virtual worlds.

Convai is a developer platform for building lifelike, voice-driven non-player characters and virtual humans. Its SDKs for Unity, Unreal Engine, PlayCanvas, and the web add end-to-end speech, LLM reasoning, long-term memory, perception, and action execution so characters can hold natural conversations, understand their surroundings, and perform in-world tasks. Studios use it to ship interactive NPCs across games, XR, and the open web.

Build playable 3D browser games with natural-language vibe coding.

Rosebud AI lets anyone build playable browser games — 2D, 3D, and multiplayer — by describing them in natural language ('vibe coding'), with no installs or manual coding required. It bundles a Game Creator plus tools like PixelVibe for AI game assets, an RPG/Visual Novel maker, and AI Storybook. Over 500,000 games have reportedly been created on the platform.