Vellium
A desktop AI app for roleplay and writing that connects to local models or cloud APIs and keeps chats and projects on your machine.
Vellium is a desktop AI app for writers and people who want conversations with fictional characters. It combines multi-character roleplay with writing projects and lets you choose the model provider.
- Character roleplay: Create chats with multiple characters, branch conversations into alternate timelines, edit messages and control automatic turns, with character-card imports and LoreBooks for world information.
- Long-form writing: Organize chapters and scenes, ask for summaries, rewrites or expansion, and import DOCX files or export to DOCX and Markdown.
- Reference collections: Give chat and writing access to knowledge collections, with optional reranking to refine the relevance of retrieved material.
- Voice and avatars: Hold live conversations with Whisper-compatible transcription and streaming speech output, alongside Inochi2D avatars with lip sync and expressions.
- Tools and extensions: Add MCP tool calls and local plugins, including extensions for themes and widgets.
Local model connections include Ollama, LM Studio and KoboldCpp. OpenRouter, Requesty and OpenAI-compatible APIs provide external model access, with requests sent to the selected provider. Chats, characters, projects, settings and knowledge collections stay in a local SQLite database. Full Local Mode blocks configured public provider endpoints; local application data isn't encrypted by default.
Vellium is open source under MIT and runs on macOS, Windows and Linux, including Apple Silicon and Intel Macs. A local web mode serves the interface in a browser without opening the desktop app.
