I've updated my old-fashioned youtube-dl.exe. It now includes the visionOS client information in the YouTube extractor. See this pull request. ./youtube-dl -v 6p7f7gAj4Uk
[debug] System config: []
[debug] User config: ['--console-title', '--rm-cache-dir', '-i', '-o', '/dev/shm/test-ytd/%(title)s.%(ext)s', '-f', 'bestvideo[height<=1080][ext=mp4][vcodec^=avc]+bestaudio[ext=m4a]/best[ext=mp4]/best', '--no-mtime', '--embed-thumbnail', '--force-ipv4']
[debug] Custom config: []
[debug] Command-line args: ['-v', '6p7f7gAj4Uk']
[debug] Encodings: locale UTF-8, fs utf-8, out utf-8, pref UTF-8
[debug] youtube-dl version 2026.08.23
[debug] Lazy loading extractors enabled
[debug] Single file build
[debug] Python 3.10.12 (CPython x86_64 64bit) - Linux-5.15.0-190-generic-x86_64-with-glibc2.35 - OpenSSL 3.0.2 15 Mar 2022 - glibc 2.35
[debug] exe versions: ffmpeg N-125972-ge13b2e00e8-Nico-20260806, ffprobe N-125972-ge13b2e00e8-Nico-20260806, rtmpdump 2.4
[debug] Proxy map: {}
Removing cache dir /home/nico/.cache/youtube-dl ..
[youtube] 6p7f7gAj4Uk: Downloading webpage
[youtube] 6p7f7gAj4Uk: Downloading VISIONOS API JSON
[youtube] 6p7f7gAj4Uk: Downloading m3u8 information
[youtube] 6p7f7gAj4Uk: Downloading thumbnail ...
[youtube] 6p7f7gAj4Uk: Writing thumbnail to: /dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.jpg
[debug] Invoking downloader on 'https://rr3---sn-u15hn5-cc.googlevideo.com/videoplayback?expire=1787486311&ei=B4yKatPKIdq6zPsP9dzOiQM&ip=<REDACTED> &id=o-AGjSrhMVDDk3_jKqNHQfGsrY2oWejYirD11QpTDBIkrK&itag=137&source=youtube&requiressl=yes&xpc=EgVo2aDSNQ%3D%3D&cps=210&met=1787464711%2C&mh=TD&mm=31%2C29&mn=sn-u15hn5-cc%2Csn-5hnekn7z&ms=au%2Crdu&mv=m&mvi=3&pl=19&rms=au%2Cau&initcwndbps=3891250&bui=AR3QkAkDt1_g3LCZjMXIxkCVc8-W0tGMIM_6sBK3NGAHf4yPJIihO2KPezPDpD_afM1QFfB8P3Cxk9Oq&spc=KBGBcsMQiLFWnlI5uJk7Z82SosMcEvnZawKZsT26x_MoqDnZ46KjcPK-kA&vprv=1&svpuc=1&mime=video%2Fmp4&rqh=1&gir=yes&clen=51343758&dur=310.000&lmt=1733645440420066&mt=1787464360&fvip=5&keepalive=yes&fexp=51565116&c=VISIONOS&txp=4532434&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cxpc%2Cbui%2Cspc%2Cvprv%2Csvpuc%2Cmime%2Crqh%2Cgir%2Cclen%2Cdur%2Clmt&sig=AE0s2JYwRQIgEWnrYi-gVj6A-TlgvUVxNIayGFITp5jJNf36jd3XAwQCIQCIrHyshicOhH93LO0Pkt1mK7ETKK5gaTIy9QKnH9ls4w%3D%3D&lsparams=cps%2Cmet%2Cmh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Crms%2Cinitcwndbps&lsig=APaTxxMwRQIhAIbAGUIA_MNMGaiw8vyLB-91zx2F4IWiqmaFGC4b7hBbAiAm2-OG5OjJ0CY1y4haN_bumVXGOfSky3M6Rmvc4oOkDQ%3D%3D'
[dashsegments] Total fragments: 5
[download] Destination: /dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.f137.mp4
[download] 100% of 48.97MiB in 00:05
[debug] Invoking downloader on 'https://rr3---sn-u15hn5-cc.googlevideo.com/videoplayback?expire=1787486311&ei=B4yKatPKIdq6zPsP9dzOiQM&ip=<REDACTED> &id=o-AGjSrhMVDDk3_jKqNHQfGsrY2oWejYirD11QpTDBIkrK&itag=140&source=youtube&requiressl=yes&xpc=EgVo2aDSNQ%3D%3D&cps=210&met=1787464711%2C&mh=TD&mm=31%2C29&mn=sn-u15hn5-cc%2Csn-5hnekn7z&ms=au%2Crdu&mv=m&mvi=3&pl=19&rms=au%2Cau&initcwndbps=3891250&bui=AR3QkAkDt1_g3LCZjMXIxkCVc8-W0tGMIM_6sBK3NGAHf4yPJIihO2KPezPDpD_afM1QFfB8P3Cxk9Oq&spc=KBGBcsMQiLFWnlI5uJk7Z82SosMcEvnZawKZsT26x_MoqDnZ46KjcPK-kA&vprv=1&svpuc=1&mime=audio%2Fmp4&rqh=1&gir=yes&clen=5018775&dur=310.056&lmt=1733642532609993&mt=1787464360&fvip=5&keepalive=yes&fexp=51565116&c=VISIONOS&txp=4532434&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cxpc%2Cbui%2Cspc%2Cvprv%2Csvpuc%2Cmime%2Crqh%2Cgir%2Cclen%2Cdur%2Clmt&sig=AE0s2JYwRQIhALLl9LTWrc7G3jETDRTX60ADlPUOzrUg4fp0VdJcojeKAiBXlb97WXpBCCIXzmqyx8TMqP6Dt5PcM6eu8AhYFi-atA%3D%3D&lsparams=cps%2Cmet%2Cmh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Crms%2Cinitcwndbps&lsig=APaTxxMwRQIhAIbAGUIA_MNMGaiw8vyLB-91zx2F4IWiqmaFGC4b7hBbAiAm2-OG5OjJ0CY1y4haN_bumVXGOfSky3M6Rmvc4oOkDQ%3D%3D'
[dashsegments] Total fragments: 1
[download] Destination: /dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.m4a.f140.m4a
[download] 100% of 4.79MiB in 00:00
[ffmpeg] Merging formats into "/dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.mp4"
[debug] ffmpeg command line: ffmpeg -y -loglevel repeat+info -i 'file:/dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.f137.mp4' -i 'file:/dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.m4a.f140.m4a' -c copy -map 0:v:0 -map 1:a:0 'file:/dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.temp.mp4'
Deleting original file /dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.f137.mp4 (pass -k to keep)
Deleting original file /dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.m4a.f140.m4a (pass -k to keep)
[ffmpeg] Adding thumbnail to "/dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.mp4"
[debug] ffmpeg command line: ffmpeg -y -loglevel repeat+info -i 'file:/dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.mp4' -i 'file:/dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.jpg' -c copy -map 0 -map 1 -disposition:v:1 attached_pic 'file:/dev/shm/test-ytd/Βέβηλος _ Ακάθαρτοι συμμ. Ματούλα Ζαμάνη.temp.mp4'