Solis

Tired of playing calendar Tetris? Our Chrome extension connects to your calendar and uses AI to detect scheduling conflicts, automatically finding better times. Solis saves time, energy, and sanity.

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Inspiration

Solis was inspired by the frustration of trying to manage a busy schedule where school, meetings, personal tasks, and unpredictable commitments constantly collide. Existing calendar apps can add events, but none intelligently help you manage them when conflicts arise. We wanted a tool that acts like a personal assistant—one that understands your routines, respects your boundaries (like bedtime or work hours), and helps you negotiate your schedule automatically. Solis was born from the idea that time management shouldn’t feel like a second job; it should be seamless, intuitive, and smart.

What it does

Solis is a Google Chrome extension that connects directly to your Google Calendar and intelligently manages your schedule, particularly in terms of rescheduling events as conflicts arise. You can add tasks through the extension, and Solis uses API calls to Google Gemini to parse the event and understand its importance to the user, especially when compared to other events. When conflicts arise, Solis automatically detects them and walks you through smart rescheduling options, finding the best times based on your preferences, work hours, and other scheduled activities/events. For conflicts as they arise in group events, Solis drafts and sends negotiation emails to all attendees with other available times, communicating rescheduling across multiple parties for the user. To help users quickly assess their schedule's flexibility, Solis also uses an intuitive color-coding system to display event flexibility (red for rigid, non-negotiable commitments like important meetings, and blue for passive events that can overlap with other tasks like studying or desk work). Every event added or edited in Solis syncs instantly with Google Calendar, making your schedule adaptive and effortless.

How we built it

We built Solis using a React frontend, a Node/Express backend, Google Calendar & Gmail APIs, and MongoDB for persistent event storage. The Chrome extension popup communicates with the backend for Gemini-powered event parsing, conflict detection, and rescheduling logic. We implemented Google OAuth authentication to link user calendars securely and created background scripts that continuously listen for new events created directly in Google Calendar. Our full-stack architecture ensures every action, from adding events and modifying preferences to rescheduling, is synced both ways between the extension and Google Calendar.

Challenges we ran into

One of the biggest challenges was architecting conflict detection and rescheduling logic. It felt difficult to determine what an accurate assessment of an "important" event was in terms of choosing between two events to reschedule, because while some events may follow more systematic logic in that sense, others were not as clear, which is where we relied on the LLM's judgement of the event's importance based on its title. Another challenge was making sure there was no distinction between events scheduled via Solis and Google Calendar. This was fixed by ensuring that all events to the same database and were analyzed in the reschedule logic looked at the same metadata across all events. Finally, coordinating LLM-derived metadata with database models and real Google Calendar data required constant debugging and iteration.

Accomplishments that we're proud of

We're proud of building a full, end-to-end intelligent scheduling system that feels like an actual assistant rather than a fancy calendar add-on. The integration between real-time Google Calendar syncing, LLM-based event classification, and dynamic conflict resolution is something most existing productivity tools don’t attempt. We also developed a scalable backend architecture and comprehensive test cases to ensure reliability.

What we learned

We learned how challenging true “smart scheduling” actually is—from designing models for event flexibility to handling complicated edge cases like cascade conflicts. Working with OAuth taught us the importance of secure token management, and building a Chrome extension revealed the constraints of popup-based UX design. Integrating LLMs into a real product forced us to balance autonomy with user control, and using real calendar data helped us appreciate how messy and sometimes "unclassifiable" human schedules truly are. Building for humans means embracing that complexity.

What's next for Solis

We want to expand the capabilities of the group rescheduling capabilities, using the LLM to actually read other parties' responses to rescheduling inquiries in order to further automate it. Long term, Solis will evolve into a full AI time-management agent that helps you make better decisions with your time by virtue of making many of managerial tasks much easier, and with user collaboration, potentially making many of these menial decisions altogether.

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