I wanted a simple way to save something that had already happened during a game on Linux. That's what I've been working on with Moment: leave it running in the tray, press F8 after a good moment, and save the previous seconds as a clip.
I'm using it on CachyOS with KDE Plasma and Wayland, and I'm looking for people willing to try the current version and report what works on their setup.
The screenshot uses sample media, not personal recordings.
The current workflow
The app keeps a rolling replay buffer while capture is active. F8 saves a replay and F9 takes a screenshot; the duration and shortcuts can be changed. Saved clips appear in a local library with search, favorites and playback.
From there, the editor can trim the start and end and export an MP4 using one of four quality presets. It currently handles simple trimming, not a multitrack timeline. The original media stays on disk.
Other features include audio-device selection, per-game capture profiles, optional Discord activity and an on-screen confirmation when a capture is saved. Closing the main window leaves the app running in the system tray.
How it's put together
Moment uses C++ and Qt Quick. Screen access goes through the XDG ScreenCast portal, and frames arrive through PipeWire. The replay buffer retains recent video frames and optional audio in memory. Saving a replay exports that interval to a video file.
SQLite keeps the local library index, and FFmpeg handles edited exports and prepares compatible MP4 copies for experimental Drive sharing. Local recording does not need an online account.
Desktop integration matters here: the compositor's portal backend controls screen permission and global shortcuts. KDE Plasma on Wayland is the setup I've been using; I still need feedback from other desktops and GPUs. There is no dedicated X11 capture backend yet.
Trying it
The code is MIT-licensed:
https://github.com/rancidavi-dotcom/MomentReplay
For Arch Linux and derivatives, the repository includes a PKGBUILD:
git clone https://github.com/rancidavi-dotcom/MomentReplay.git
cd MomentReplay
makepkg -si
There are also manual CMake instructions in the README. Google Drive sharing still needs an OAuth-configured build, so the main workflow to try first is capture, save, browse and trim.
I'm particularly interested in feedback on hotkey reliability while a game has focus, audio synchronization, replay memory use and long-session stability. A bug report with your distribution, desktop, GPU and reproduction steps would help a lot.
Transparency: Moment is conceived and led by a human, with AI assistance in development. AI also assisted in preparing this post.
Top comments (1)
Instant replay is a great use case for making capture invisible until it matters. The tricky edges are storage limits, capture latency, audio device switching, and a reliable way to protect a clip before the rolling buffer overwrites it.