Overview¶

Rewyt is built with Go, Svelte, dash.js, and packaged with Wails. It runs on top of ypb, a playback proxy built around MPEG-DASH to provide access to past moments in YouTube live streams.

sequenceDiagram
    autonumber
    participant A as Frontend<br/>(Svelte + Shaka Player)
    participant B as Backend<br/>(Go)
    participant C as ypb
    participant Y as YouTube

    note over B,C: Startup
    B->>C: Start server
    C->>Y: Fetch info (via yt-dlp)
    Y-->>C: Video info

    note over A,C: Rewind to moment
    A->>C: Request MPD
    C->>C: Generate MPD
    C-->>A: MPD (proxied base URLs)

    note over A,C: Playback
    loop
        A->>C: Request segment (proxied URL)
        C->>Y: Request segment
        Y-->>C: Stream segment
        C-->>A: Stream segment
    end

On startup, the Go backend starts ypb, which fetches video information via yt-dlp, including media segment base URLs for each available format. When you rewind to a moment, the frontend asks for an MPEG-DASH manifest started from that moment. During playback, the dash.js player streams video from YouTube through ypb, using its proxied URLs.