Sei
Sei is a desktop application for macOS and Windows that brings AI characters into existing video games as second players, enabling real-time play, voice calls, and shared experiences. It supports games like Minecraft, Stardew Valley, and Don't Starve Together, with a Backseat mode for watching any game or video. The app offers cloud-based AI inference or a bring-your-own-key local mode, with long-term memory stored locally on the user's machine.
- AI Agents
- Gaming & eSports
- Artificial Intelligence
- Applications
- Software Only
Funding
Founders
Founder details are not available yet.
Product
Problem
Gamers who want companionship while playing often find that traditional multiplayer requires coordinating with human players, which can be inconvenient or intimidating. Existing AI companion platforms are typically limited to text-based chat, lacking the ability to participate in actual gameplay or provide a shared interactive experience.
Solution
Sei provides a desktop application that brings AI characters directly into existing video games as second players, allowing users to play and talk with their AI companions in real time. The app supports popular games like Minecraft, Stardew Valley, Don't Starve Together, Chess, and Draw!, with Baldur's Gate 3 coming soon. Users can summon up to four unique AI characters, engage in voice calls while gaming, and even import companions from other platforms to preserve their existing relationships. A Backseat mode lets companions watch any game or video on screen, hear game audio, and react with spoken commentary. Sei offers both cloud-based inference and a bring-your-own-key mode where users run the AI locally with their own API key or a local model.
Target Audience
Primary users are gamers who want AI companionship during play sessions, as well as existing AI companion platform users seeking to extend their characters into interactive gaming experiences. The Backseat mode also appeals to streamers and content creators who want a reactive co-commentator.
Features
- Real-time AI gameplay integration with existing titles like Minecraft, Stardew Valley, Don't Starve Together, Chess, and Draw!, with Baldur's Gate 3 coming soon
- Backseat mode that shares screen and game audio so companions can watch and react to any game or video with spoken commentary
- Voice call functionality that lets users talk with AI companions while playing together
- Character library supporting up to four unique AI gamers, with the ability to import companions from other platforms including their long-term memory
- Long-term memory that persists across sessions and games, stored locally on the user's machine
- Cloud-based AI inference through Anthropic's API, or bring-your-own-key mode for local, self-hosted operation with a local model
- Shared character library with public visibility options, moderated through OpenAI and SightEngine for content safety
- Cross-platform desktop support for macOS and Windows with encrypted local session storage
- Clip saving that captures the last 15 seconds of gameplay automatically