Twitch in Steam Gaming Mode — a Decky Loader plugin for Steam Deck / Bazzite / SteamOS.
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Part of the Necrosiak plugin suite, alongside SkullKey, Steamcord and BC250-Toolkit. The plugin UI is translated into 9 languages and follows your SteamOS language automatically.
BoneCast puts everything you need to stream to Twitch right in the Steam Quick Access Menu — no desktop, no keyboard, gamepad-friendly from login to going live.
- One Twitch login (device code — gamepad friendly): you enter a short code on
twitch.tv/activate, and BoneCast fetches your stream key automatically. No manual copy-paste, ever. - Go live from the QAM — one button starts and stops the RTMP stream. A ● LIVE badge shows while you're broadcasting.
- Editable stream title — set it from the plugin, changeable even while live.
- Automatic game category — read from the running Steam game (works for non-Steam shortcuts too) and updated on the fly. Falls back to Just Chatting when a game has no matching Twitch category.
- Transparent chat overlay — read-only Twitch chat drawn over the game in Gaming Mode (gamescope external-overlay plane), with native + BTTV / 7TV / FFZ emotes. Position, size and opacity are adjusted live from the QAM, and it stays visible even with Big Picture focused.
- 🎬 Instant clips — while live, one button clips the last ~30 seconds through the Twitch API; the clip lands on your dashboard about 15 seconds later.
- 💬 Talk in your own chat — send messages to your Twitch chat straight from the QAM, no keyboard-over-desktop gymnastics.
- ⏸️ BRB mode — one tap swaps the game feed for a clean pause screen and mutes your mic; one tap brings you back. The stream never drops.
- ⏺️ Local recording — save your session as an MKV in
~/Videos/BoneCast/, either alongside the live stream or without streaming at all (no stream key involved). - Live mic mute — cut your microphone on the stream with one tap, without stopping the broadcast (and without muting your Discord call).
- Stream settings per account — resolution, fps, video/audio bitrate, keyframe interval, and an auto-detected encoder (NVENC ▸ VAAPI ▸ software x264). Only encoders that actually work on your hardware are offered.
- Discord audio bridge (when Steamcord is installed): an optional toggle mixes your Discord voice into the stream, so your party is heard by viewers — while you still hear them normally.
Twitch has no video-push API, so going live always means an RTMP push under the hood. BoneCast handles it for you:
- OAuth device flow logs you into Twitch and pulls your stream key, title and category through the Helix API — you never touch the key.
- The game frame is captured from gamescope into a
v4l2loopback device, and ffmpeg encodes it (hardware when available, softwarelibx264otherwise) and pushes it tortmp://…/<your-key>. - The chat overlay is a transparent WebKit surface promoted to the gamescope external-overlay plane, reading Twitch IRC anonymously and rendering emotes.
Everything is driven from the QAM and survives reboots.
- Install Decky Loader.
- Enable Developer Mode in Decky's general settings, then Decky settings → Developer → Install plugin from URL:
https://github.com/Necrosiak/BoneCast/releases/latest/download/BoneCast.zip(or grabBoneCast.zipfrom the Releases page and install from ZIP). - Open the Quick Access Menu → BoneCast, log in to Twitch, and go live.
BoneCast auto-updates itself from GitHub Releases (toggleable in the plugin's Updates section).
A note on automatic updates. Decky owns the plugin's top-level directory, so the built-in updater can rewrite existing files but cannot create new ones. A release that adds a file at the top level therefore has to be installed the normal way — Install plugin from URL, above — rather than through the automatic update. The release notes say so whenever that is the case.
BoneCast targets every Linux distro that can run Steam in Gaming Mode / Big Picture: one build, runtime detection of everything external (ffmpeg, libx264, v4l2loopback, GStreamer), and the exact install command for your package manager shown in the QAM when something is missing. Per-distro package notes: docs/OS-NOTES.md.
Found a bug, something misbehaving on your distro, or missing a feature? Please open an issue — every report directly shapes what gets built next. Include if you can:
- your distro & version (Bazzite 42, CachyOS, Ubuntu 24.04…) and your GPU (for the encoder probes)
- the plugin version and what you were doing (going live, overlay, OAuth…)
- what you expected vs what happened
- logs:
~/homebrew/logs/BoneCast/
Feature requests and "it works!" reports on unusual setups are just as valuable.
Created and maintained by Necrosiak. Part of the Necrosiak plugin suite for Steam Gaming Mode.
AI was used in the making of this project — for reverse engineering, development and documentation. It was not used for any art or creative writing. Everything released publicly is reviewed by a human, and the results are my responsibility. If that is not something you are comfortable with, now you know.