RisuAI (often shortened to Risu) is a free, open-source AI roleplay platform aimed at power users who want fine control over their character chats. Rather than locking users into a single proprietary model, RisuAI acts as a flexible frontend that connects to a wide range of AI backends, including OpenAI, Anthropic Claude, Google Gemini, DeepInfra, Ooba, and OpenRouter, using the user's own API keys. This bring-your-own-key model means users pay providers directly and retain control over which model powers each conversation.
The application is deliberately feature-rich. It supports emotion images that change with a character's mood, custom prompt templates, prompt injection, inline images and assets within chats, regex-based scripting for advanced behavior, and long-term memory to maintain continuity across sessions. These capabilities target experienced roleplayers and tinkerers who want to script and customize their experience well beyond what consumer companion apps allow.
RisuAI is genuinely cross-platform, with native builds for Windows, macOS, Linux, and Android plus a full web app, and it is built with Svelte, TypeScript, and WebGPU. The project is open source with code on GitHub, so users can inspect, fork, and contribute, and the architecture keeps conversations under the user's own control rather than routed through a single vendor's servers.
Characters are created and shared through RisuRealm, the platform's community hub, giving users a library of community-made personas to download alongside their own creations. Because RisuAI is open source and BYO-key, it does not have traditional subscription pricing; costs come from whichever model provider a user connects.
It is best suited to technically comfortable users who value openness, model flexibility, and deep customization. Casual users wanting a turnkey, hosted companion may find the setup overhead higher than fully managed apps.