Read AirTag data from the FindMy.app cache and convert to GPX

airtag-to-gpx-sync.sh

#!/usr/bin/env bash

# 
# Reads AirTag data from the FindMy.app cache and converts it to a daily GPX file
#
# Rsyncs the data to a web accessible folder that can be displayed with e.g. 
# https://gist.github.com/henrik242/84ad80dd2170385fe819df1d40224cc4
#
# This should typically be run as a cron job
#

set -o pipefail -o nounset -o errexit

export PATH=/usr/local/bin:$PATH
DATADIR=/tmp/airtag-data
TODAY=$(date +%d)

mkdir -p $DATADIR
DATA=$DATADIR/airtagdata-$TODAY.txt
GPX=$DATADIR/airtagdata-$TODAY.gpx
TAGNAME=Foobar

if [[ $(uname -s) == "Darwin" ]]; then
  TOMORROW=$(date -v +1d +%d)
else
  TOMORROW=$(date --date="tomorrow" +%d)
fi
rm -f $DATADIR/airtagdata-$TOMORROW.gpx

jq -r '.[] | select(.name == "'$TAGNAME'") | .location | "\(.latitude) \(.longitude) \(.altitude) \(.timeStamp/1000 | todate)"' \
   $HOME/Library/Caches/com.apple.findmy.fmipcore/Items.data >> $DATA

START='<?xml version="1.0" encoding="UTF-8"?>
<gpx xmlns="http://www.topografix.com/GPX/1/1" xmlns:mytracks="http://mytracks.stichling.info/myTracksGPX/1/0" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" creator="myTracks" version="1.1" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd">
   <trk>
      <name>'$TAGNAME'</name>
      <extensions>
         <mytracks:color red="0.000000" green="0.000000" blue="1.000000" alpha="1.000000" />
         <mytracks:area showArea="no" areaDistance="0.000000" />
         <mytracks:directionArrows showDirectionArrows="yes" />
         <mytracks:sync syncPhotosOniPhone="no" />
         <mytracks:timezone offset="120" />
      </extensions>
      <trkseg>'

END='      </trkseg>
   </trk>
</gpx>'


echo $START > $GPX 

function elems() {
    LAT=$1
    LON=$2
    ELE=$3
    TS=$4
}

cat $DATA | while read line; do
  elems $line
  echo '<trkpt lat="'$LAT'" lon="'$LON'">
            <ele>'$ELE'</ele>
            <time>'$TS'</time>
         </trkpt>' >> $GPX
done

echo $END >> $GPX
cp $GPX $DATADIR/airtagdata.gpx

rsync -a --exclude='*.txt' $DATADIR example.com:public_html/airtag/

A full decryption tool for macOS 14.4+ FindMy cache data has been published at https://github.com/Pnut-GGG/findmy-cache-decryptor

Nice!