Kavynex

Kavynex is a desktop app for archiving YouTube channels and playing back what you saved.

Downloading the video is the easy part. What goes with a channel and does not come back is everything around it, so Kavynex saves the comment section and the live chat replay alongside the media, keeps all of it in a library on your own disk, and plays it back offline. No server, no container, no account. It is an application you install.

It was built to preserve the channels I follow, and it is what I use for that.

Features

Archiving

• Back up a channel's video and audio with yt-dlp
• Save the comment section, with the reply threads rebuilt as they were
• Save a stream's live chat and replay it alongside the video, in sync through seeks
• Save thumbnails with the media they belong to

Your library

• Organize media by channel, with the channel avatar fetched from its handle
• Import video and audio files you already have on disk
• Search, filter and sort within a channel
• Mark media watched or unwatched
• Resume where you stopped
• Reconcile the database against the files on disk with the built-in diagnostics
• Everything stays local, so nothing is uploaded, and loading remote images is off by default

Requirements

For normal use, Kavynex requires:

• yt-dlp
• FFmpeg

Make sure yt-dlp and ffmpeg are installed and available in your system PATH.

If you cannot change your PATH (a locked-down work machine, or a portable install you want to keep self-contained), drop the executables into a tools/ folder inside the app's data directory instead. Kavynex falls back to it when the PATH lookup finds nothing. docs/DIRECTORIES.md lists that directory per OS, and docs/TROUBLESHOOTING.md covers how the lookup works and what the in-app Diagnostics dialog reports about it.

Installation

Prebuilt installers and packages are available on the latest GitHub release:

Download the latest release

Windows

Download the installer matching your processor, arm64 for a Windows on ARM device (Snapdragon and similar), x64 for everything else:

• kavynex_*_x64-setup.exe
• kavynex_*_arm64-setup.exe

The .msi package is also available if you prefer it:

• kavynex_*_x64_en-US.msi
• kavynex_*_arm64_en-US.msi

macOS

Download the package according to your Mac:

• Apple Silicon / M1, M2, M3, M4: kavynex_*_aarch64.dmg
• Intel Mac: kavynex_*_x64.dmg

Linux

Choose the package according to your distribution, in the build matching your processor. The amd64/x86_64 files are for a normal 64-bit PC, the arm64/aarch64 ones for an ARM machine (a Raspberry Pi 5, an Ampere server, an ARM cloud VM):

• AppImage: kavynex_*_amd64.AppImage / kavynex_*_aarch64.AppImage
• Debian/Ubuntu: kavynex_*_amd64.deb / kavynex_*_arm64.deb
• Fedora/RHEL/openSUSE: kavynex-*.x86_64.rpm / kavynex-*.aarch64.rpm

(The architecture is spelled differently by each packaging format. That is the format's convention, not an inconsistency in the build.)

Verifying a download

The installers are not code-signed (a deliberate tradeoff explained in docs/RELEASE-SECURITY.md), so SmartScreen/Gatekeeper will warn on first run. To confirm a download is authentic:

• Compare its hash against SHA256SUMS.txt, published alongside the installers.

• Or, with the GitHub CLI, verify its build provenance:

  gh attestation verify <installer-file> --repo eduardoghi/kavynex
  

  A successful check confirms the file was built by this repository's release workflow.

Both apply from v1.2.0 onward. The checksum and provenance steps were added to the release workflow after v1.1.1 was published, so v1.1.1 and earlier have neither, and gh attestation verify will report no attestation for those installers rather than a failure to trust.

Screenshots

Channel library

YouTube import

Video player

Live chat backup

Diagnostics

Light theme

Development

To run the project from source, you need Node.js, pnpm, Rust, yt-dlp, and FFmpeg.

pnpm install
pnpm tauri dev

Build

pnpm tauri build

Tests

pnpm test:run

(pnpm test runs the same suite in watch mode.) See CONTRIBUTING.md for the Rust suite and the rest of the checks CI runs.

Troubleshooting and privacy

Both outgrew being README sections and now have documents of their own:

• docs/TROUBLESHOOTING.md: yt-dlp/FFmpeg not being found, the app not starting (WebView2 on Windows, Gatekeeper on macOS, FUSE and WebKitGTK on Linux), a library on a drive that is not connected, why adding a video again downloads nothing or keeps the file you already have, a corrupted database, why "Open file location" behaves differently on each platform, and where the log file lives.
• docs/PRIVACY.md: everything Kavynex stores, the only three things it sends over the network, and how to take your data with you or remove it.

Third-party assets

Kavynex's own code is MIT (see LICENSE). The one bundled asset under a different license is the display typeface used for headings, Bricolage Grotesque, licensed under the SIL Open Font License 1.1. The OFL permits bundling a font inside an application without affecting that application's own license, but it does require the copyright notice and license text to travel with the distribution, so the font's license is shipped verbatim as licenses/bricolage-grotesque-OFL-1.1.txt inside the app bundle (from public/licenses/ in this repository), and applies to the font files only, not to Kavynex itself.

More documentation

• docs/ARCHITECTURE.md: the layered backend/frontend architecture, the IPC boundary, and a walk-through of the main flows (adding media, changing the library folder, database recovery).
• docs/decisions/: why a handful of non-obvious shapes were chosen, and what breaks if one of them is reverted.
• docs/DATABASE.md: the SQLite schema, migrations, and backup/restore/export/import model.
• docs/DIRECTORIES.md: the runtime directories and library layout the app uses on disk.
• docs/TROUBLESHOOTING.md: what to do when something does not behave the way you expect, and where the log file lives.
• docs/PRIVACY.md: what Kavynex stores, what it sends over the network, and how to take your data with you or remove it.
• docs/RELEASING.md: how a release is cut and published (needs repository write access).
• CONTRIBUTING.md: development setup, commands, and commit conventions.
• docs/THREAT-MODEL.md: what the app defends against at runtime: the IPC trust boundary, path safety, the capability grants, the asset-protocol scope and the CSP.
• docs/RELEASE-SECURITY.md: what makes a shipped build verifiable: the updater, why installers are unsigned, checksums, build provenance, the SBOM, static analysis and the dependency supply chain.
• SECURITY.md: how to report a vulnerability, and which versions are supported.
• SUPPORT.md: where to report a bug, what to include, and what to expect.
• CODE_OF_CONDUCT.md: the standard expected of everyone taking part, and how to report a problem.