A standalone app. It does not modify Discord's install: it attaches to the running client over the Chrome DevTools Protocol, injects a small tap into the renderer, and pulls frames out. Turning it off really turns it off, and a Discord update cannot break it.

flowchart LR
    subgraph Discord ["Discord renderer"]
    direction TB
        A["injected payload.ts\n(find per-user <video>)"]
        B["MediaStreamTrackProcessor"]
        B --> A
    end

    subgraph NDI ["Discord-NDI (Bun)"]
    direction TB
        C["ndi.ts + grandiose"]
        D["1 NDI sender/source\n'Discord – Alice'"]
        E["ui.html control panel"]
        C --> D
    end

    Discord -- "[24B hdr][BGRA]\nws://127.0.0.1:9191" --> NDI
    NDI -- "injected over CDP" --> Discord

Even though the app heavily relies on NDI, you don't actually need to use NDI at all. Just like StreamElements or VDO.ninja, Discord-NDI hosts a local web server that allows you to easily import participant cameras directly into OBS Studio!

Simply open the http://127.0.0.1:9333 control panel, click on the Web Source link for any participant, and paste that URL directly into an OBS Browser Source.

All video frames are seamlessly pulled straight over WebSockets without any NDI configuration required.

# Clone the repository and install dependencies
bun install --cwd app

# Run the backend
bun run app/index.ts

This opens a control panel at http://127.0.0.1:9333 with a live list of what is publishing. Capture starts automatically with the process; per-source rows can each be paused.

If you prefer to start Discord manually with CDP enabled:

open -a Discord --args --remote-debugging-port=9222

• --port: Frame ingest port (default: 9191)
• --debug-port: CDP port (default: 9222)
• --ui: Web panel port (default: 9333)
• --headless: Run without the web panel wrapper
• --dry: Run without starting actual NDI outputs

If macOS throws the "Discord-NDI is damaged and can't be opened" error when you launch the app, this is Apple's Gatekeeper blocking unsigned open-source applications downloaded from the internet.

To bypass this safely, open your Terminal and remove the quarantine attribute:

xattr -cr /Applications/Discord-NDI.app

Discord's <video> elements are created imperatively and carry no React fiber, so we rely on DOM footprinting:

1. Who: The enclosing tile tags itself data-selenium-video-tile="<userId>".
2. Camera vs Go Live: Both share that ID. Cameras render inside previewWrapper_*, whereas Go Live streams render inside videoContainer_*. Class hashes frequently change, so the match relies securely on prefixes.
3. Names: Video tiles carry no display name, and without an injection mod like Vencord, we cannot query Discord's internal stores. Identifiers are instead extracted from the member sidebar list, pairing a usernameFont_* label against the user's avatar URL.

Discord-NDI republishes other people's video. It is purposefully built to verify consent:

• It refuses to attach unless you have Discord's Activity Status enabled (the setting that broadcasts your current activity/game to others). No activity sharing → no capture.
• During capture, it automatically toggles Discord's Streamer Mode to protect your on-screen personal information, acting as a clear indicator that the active session is being broadcasted/recorded.

See app/index.ts (Controller.start) and app/payload.ts for the enforcement implementations.

The app is written in plain Bun, making Electrobun the natural wrapper: its main process is Bun, and grandiose is a native N-API addon. Its binary references standard Node APIs, meaning it loads smoothly without requiring V8/Node rebuilds.

• Bandwidth: Frames cross the WebSocket entirely uncompressed. At 720p 30fps BGRA, bandwidth is roughly ~55 MB/s per source. This performs effortlessly within loopback for up to about four simultaneous sources. Beyond that, scaling would require WebCodecs or a move to Shared Memory bindings.
• Timing constraints: Sender frame rate is pushed as a flat 30fps. Ensure your receivers sync off the transmitted timecode instead of expecting realtime locking.
• Transformations: Output is unmirrored (even where Discord mimics a mirror on your own preview), and scaling tracks Discord's own internal dynamic resolutions instead of pinning one standardized size.
• Discord ToS: Client automation inherently violates Discord's Terms of Service. While enforcement against non-spam tooling continues to be virtually non-existent, run this entirely with your own discretion.