standalone programs which take an audio file as argument

you may want to forget about all this fancy complicated stuff and just use event hooks instead (which doesn't need -e2ts or ffmpeg)

NOTE: these all require -e2ts to be functional, meaning you need to do at least one of these: apt install ffmpeg or pip3 install mutagen

some of these rely on libraries which are not MIT-compatible

audio-bpm.py detects the BPM of music using the BeatRoot Vamp Plugin; imports GPL2
audio-key.py detects the melodic key of music using the Mixxx fork of keyfinder; imports GPL3

these invoke standalone programs which are GPL or similar, so is legally fine for most purposes:

media-hash.py generates checksums for audio and video streams; uses FFmpeg (LGPL or GPL)
image-noexif.py removes exif tags from images; uses exiftool (GPLv1 or artistic-license)

these do not have any problematic dependencies at all:

cksum.py computes various checksums
exe.py grabs metadata from .exe and .dll files (example for retrieving multiple tags with one parser)
wget.py lets you download files by POSTing URLs to copyparty
- also available as an event hook

dangerous plugins

plugins in this section should only be used with appropriate precautions:

very-bad-idea.py combined with meadup.js converts copyparty into a janky yet extremely flexible chromecast clone
- also adds a virtual keyboard by @steinuil to the basic-upload tab for comfy couch crowd control
- anything uploaded through the android app (files or links) are executed on the server, meaning anyone can infect your PC with malware... so protect this with a password and keep it on a LAN!

dependencies

run install-deps.sh to build/install most dependencies required by these programs (supports windows/linux/macos)

alternatively (or preferably) use packages from your distro instead, then you'll need at least these:

copyparty -e2dsa -e2ts followed by any combination of these:

-mtp key=f,audio-key.py
-mtp .bpm=f,audio-bpm.py
-mtp ahash,vhash=f,media-hash.py
f, makes the detected value replace any existing values
the . in .bpm indicates numeric value
assumes the python files are in the folder you're launching copyparty from, replace the filename with a relative/absolute path if that's not the case
mtp modules will not run if a file has existing tags in the db, so clear out the tags with -e2tsr the first time you launch with new mtp options

instead of affecting all volumes, you can set the options for just one volume like so:

copyparty -v /mnt/nas/music:/music:r:c,e2dsa:c,e2ts immediately followed by any combination of these: