Legal

Third-party licenses

Sift ships with these open-source programs and models. Each is under its own license, and we're grateful to the people who make them. Sift unpacks the programs into ~/Library/Application Support/Sift/bin on first launch and runs them as separate processes.

Bundled with the app

Component	Version	License	Source
FFmpeg (ffmpeg, ffprobe)Built from the ffmpeg.org source as an LGPL build (no GPL or non-free parts), statically linked, run as separate programs.	7.1.5	LGPL-2.1-or-later	Source
dav1d (inside FFmpeg)AV1 decoder, linked into the FFmpeg build.	1.5.4	BSD-2-Clause	Source
whisper.cpp (whisper-cli, whisper-server)Speech-to-text on your Mac, with Metal.	v1.9.4	MIT	Source
yt-dlpThe macOS release build. It bundles CPython and its dependencies, each under its own license.	2026.08.19	Unlicense	Source
ONNX Runtime Web (onnxruntime-web)Runs the YAMNet sound model.	1.30.0	MIT	Source
YAMNet modelGoogle's AudioSet sound-event model, converted to ONNX. Finds applause, cheering and other cues.	—	Apache-2.0	Source
PGliteThe embedded database. It is a build of PostgreSQL, which is under the PostgreSQL License.	0.5.8	Apache-2.0	Source

FFmpeg and the LGPL

FFmpeg is licensed under the GNU Lesser General Public License, version 2.1 or later. Sift's FFmpeg is built from the unmodified FFmpeg 7.1.5 source without GPL or non-free components (the build refuses --enable-gpl and --enable-nonfree), and runs as its own ffmpeg and ffprobe programs rather than being linked into Sift. FFmpeg is a trademark of Fabrice Bellard.

Downloaded during setup

Model	License	Source
Whisper large-v3-turbo (ggml, q5_0)OpenAI's Whisper weights in whisper.cpp's format. Downloaded from Hugging Face during setup, not shipped in the app.	MIT	Source

Runtime

The Sift app is compiled with Bun (MIT). Bun includes JavaScriptCore from WebKit, which is under the LGPL-2.0, and other components under their own licenses; see Bun's licensing page.