Inspiration
Winnipeg has extreme seasons, and the weather changes how we feel. We wanted a fun way to turn that shared feeling into something social—so instead of everyone streaming alone, people can instantly join a room and listen together. We also wanted the project to feel Winnipeg-first by adding an “Explore Winnipeg” section to highlight local places, culture, and traditions.
What it does
Nexus turns the current weather in Winnipeg into a mood, then starts a synced listening room where everyone hears the same track at the same moment (phone + web).
Core features:
- Weather → Mood: Pulls live Winnipeg weather (OpenWeather) and maps it into a mood (Cozy/Chill/Focus/Hype, etc.).
- Create/Join Room: Users enter their name, create a room (auto-generates a 6-digit code), or join with a code.
- Synced Playback: When a room starts, the song start time is scheduled using server time so new joiners play at the same timestamp.
- Live Chat: Room chat so people can talk while listening.
- Listener Count: Shows how many people are currently in the room.
- Voting: While the current track plays, users vote the next track and the highest-voted option becomes next in the queue.
- Explore Winnipeg (Impact Feature): A curated gallery of local places/culture with images + descriptions to help people learn and connect with Winnipeg.
How we built it
- Frontend: React Native (Expo) + TypeScript with Expo Router
- Weather API: OpenWeather (
q=Winnipeg,CA&units=metric) - Realtime sync + chat + votes: Firebase Realtime Database (RTDB)
- Audio: Expo AV
- Sync approach:
- Store a shared
startedAttimestamp (server-aligned) in RTDB - Clients compute
serverNow()using a live server offset - On join, clients seek to
serverNow() - startedAtso playback matches the host
- Store a shared
- Explore Winnipeg content: Simple dataset (title, description, image URL) displayed as cards/gallery.
Challenges we ran into
- Audio sync drift: Different devices load and buffer audio at different speeds, especially web vs phone. We solved this by using a server-time offset and doing a “resync” correction after the track loads.
- Cross-platform audio quirks: Some audio formats behaved differently on web vs mobile. We adjusted by using a consistent loading/play pipeline and better error handling.
- Realtime data structure: Designing RTDB paths for rooms, playback sessions, votes, chat, and presence took iteration to avoid conflicts and keep it simple.
Accomplishments that we're proud of
- A working MVP that syncs the same music moment across multiple clients.
- Real-time features working together: presence count, chat, votes, and playback state.
- A strong “Winnipeg impact” direction with Explore Winnipeg, turning the app into more than just a music tool.
What we learned
- Real-time synchronization is more than “play at the same time”—you need server time, buffering strategy, and drift correction.
- Firebase RTDB is great for fast prototyping of real-time interactions (chat/votes/presence).
- Building for web + mobile at once reveals edge cases early and makes the product stronger.
What's next for Nexus
- Better queue system: lock in “current track”, then automatically switch to the winning next track at the end.
- More moods + playlists: 3+ curated tracks per mood, with local Winnipeg artists featured.
- Explore Winnipeg expansion: add Indigenous culture spotlights, event highlights, and community submissions.
- Room moderation + safety: basic filters, report tools, and better room controls.
- Location support: allow any city (not only Winnipeg) while keeping Winnipeg as the featured default.
Built With
- chat
- expo-av
- expo-router
- firebase
- github
- openweather
- openweather-api
- playback-sync
- presence
- react-native
- typescript
- typescript-?-react-native-(expo)-?-expo-router-?-expo-av-(audio-playback)-?-firebase-realtime-database-(rooms
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