This is perfect, I have used this on the manifest of all games created by GUI, and it shows exactly what I needed - size of the library. Now I have a clue of how much space I would need to dedicate for backups. Whether or not you incorporate it in the main GUI, combo of tools like these are going to make personal game copy preservation automated and easier.
Thank you.

On a side note: I have to admit that I have just discovered the "right click on Add To Manifest, then click Download All option" thing ("discovered", as in, I have finally and carefully read the text in the biggest info button on screen). Needless to say, before that, I started adding game by game to manifest, manually, to use for ManifestDB. The horror... of not reading manuals.

One issue I encountered: Exactly at the game titled "Kajko i Kokosz", script dropped an error (I didn't remember to copy error details, but in command line error 503 and "Will try again" was mentioned).
But for this issue, I have healing - First I tried was clicking on the next game on the list (Kerbal Space Program), and clicking "Manifest for all", but it gave 503 error again. Then I clicked on "Kajko i Kokosz" - same error.
Here's the healing part - I exited the GUI, opened it up again, clicked on KSP, then "Manifest for all" and it worked.

"Kajko i Kokosz" was recently announced for delisting, and I also bought it at around that time. :) Could that be the problem with adding the game to manifest, now that it is delisted? If you need, I can check if the issue is reproducible with fresh GUI install, and copy errors.

Off-topic: In one recent thread, regarding rep points, Red Green was mentioned. Have you heard of Possum Lodge Podcast?

Checking if my previous comment will pop up.
EDIT: Yes, it did, apologies for the clutter.

Anyway, I had some time, so I did "Manifest for All" retrieval again, with fresh install of GUI.

Process stopped at "Kajko i Kokosz" again, with pop-up error "Retrieval failed! Error 3". But this time, i clicked on next game in the list, KSP, and after initiating "Manifest for All", it continued retrieval without issues. Restarting GUI wasn't needed this time around.

Manual adding of "Kajko i Kokosz", as expected, fails as well.

No apology needed. :)

Glad you got it sorted, and yes sometimes a game will, get de-listed, though in my experience it will only be unavailable through your manifest if it is a demo. If you paid for the game, it should still have an entry, de-listed or not.

Another thing that does happen, is a game can get renamed, and after you refresh your games list, you might have a duplicate entry issue, and one will work and one won't ... or maybe not, and it is just an issue of a title mismatch with an ID check ... I forget. I've certainly seen GOG rename a few games ... a few recently. Not sure if they ever change the Game ID, though I know there can be different IDs sometimes in your wishlist compared to the manifest ones. I've been told that is based on a game update scenario ... perhaps from pre-release basis to released.

I don't know if you have ever noticed with your online GOG Library, but on the odd occasion when you check it, and it is sorted correctly, the odd older purchase will be at the start of the list. This is generally an indicator of a game name change. I have seen that happen a few time when the Roman Numeral has been changed to a regular number or vice-a-versa. Perhaps a mistake was made when they first gave the game its title.

Yes, a few buttons and the main 'Games' list of course, have right-click options.
That was my way of reducing the clutter, keeping the GUI as simple looking as I could, while still offering all the needed features.
It is tricky that approach, as not everyone reads all the instructions or checks out the tutorials very deeply ... no doubt most don't. Plus I haven't kept up with the Wiki Tutorials. In some ways these somewhat hidden features are like little Easter Eggs in my program.

Pretty sure I have heard of it, but don't think I have ever checked it out. I'm not much of a podcast listener. Not because I am not interested, but purely because I lack the time and motivation due to all that goes on in my life. I am also guilty of still having many Red Green Show episodes left to watch, and I'd rather be watching them than listening to a related podcast.

Thanks for letting me know anyway, and the feedback. :)

v1.8 of GetGameInfo, a complimentary program to GOGcli GUI has now been uploaded to GitHub.

This update is a major one and adds future support for GOGcli GUI with the manifest files it can create. I am currently adapting GOGcli GUI for this, which is nearly finished.

One of the included improvements, is using gogcli.exe and a Cookie.txt file to get needed file names and checksums.

DOWNLOAD & SCREENSHOTS & INFO - https://github.com/Twombs/GOGcli-GUI/releases/tag/v1.8g

IMPORTANT - The 'Settings.ini' file has been renamed to 'Options.ini'. Prior users will need to rename manually, before running this update (to make life easier). This has been done so that the program can be run from the GOGcli GUI folder, if you wish to.

Stay Tuned!

GetGameInfo v1.9 is now available.

Bugfix etc Update.

DOWNLOAD & SCREENSHOTS & INFO - https://github.com/Twombs/GOGcli-GUI/releases/tag/v1.9g

IMPORTANT - See details from previous post of mine.

NOTES - The bugfix is in relation to bytes recorded in the created manifest. For some reason there is a disparity between what a GOG SDK query returns and what gogcli.exe returns, with the gogcli value being the correct one. Not sure how often that happens, but my first download test revealed the issue to me.

I also discovered that some image downloads were incomplete. No idea what caused that, and it only occurred to several cover (larger) images for me, and never the boxart images. Might be some temporary issue was at play or something on my system. Anyway, in order to more easily deal with this issue if discovered, I have added a 'Replace' button to the program, which avoids the user having to manually delete any corrupted image file and then do the ADD process again. One or both images (boxart and cover) can be replaced with a few clicks (delete and download again).

P.S. If you are feeling adventurous then check the following out. Testers always welcome.

https://github.com/Twombs/GOGcli-GUI/tree/main/Work-In-Progress

GetGameInfo v2.0 is now available.

Couldn't resist doing more improvements while testing.

DOWNLOAD & SCREENSHOTS & INFO - https://github.com/Twombs/GOGcli-GUI/releases/tag/v2.0g

IMPORTANT - See details from previous 2 posts of mine above.

GetGameInfo v2.1 is now available.

Further improvements.

DOWNLOAD & SCREENSHOTS & INFO - https://github.com/Twombs/GOGcli-GUI/releases/tag/v2.1g

EARLIER RELEASES - https://github.com/Twombs/GOGcli-GUI/releases

IMPORTANT - See details from previous 3 posts of mine above.

And for those feeling adventurous, check the following work-in-progress update out for GOGcli GUI v2.9. Now supports multiple manifest selection and more error handling etc. See the included Instructions.txt file on how to use.

https://github.com/Twombs/GOGcli-GUI/tree/main/Work-In-Progress

In regard to problematic games with GOGcli GUI, where I haven't been able to create or update a manifest entry, I have had this happen so far with the following games.

Card Shark Demo (belatedly added)
Dying Light: The Following (Enhanced Edition)
Legend of Grimrock
Legend of Grimrock 2

Plus one or two others, that I haven't kept a specific record of.

Legend of Grimrock I was able to get all the manifest data for using my GetGameInfo program, and then download all the files with GOGcli GUI, using the new DOWNLOAD OTHER option, including verifying size and checksums.

Legend of Grimrock 2 was similar, except for one file, the main game EXE. I was able to get the filename, by starting to initiate a download with the browser link in my browser. I added that to the entry in the manifest created by GetGameInfo, to then download all files using GOGcli GUI. All but that problem file verified correctly. I then used my GOGPlus Download Checker program to verify that file.

As for Dying Light: The Following (Enhanced Edition), I was initially able to get all the required manifest data using GetGameInfo, but subsequent tries failed with 3 files. I did subsequent tries, because I was still developing GetGameInfo at the time. Luckily I had backed up the data, so was able to download all files for the game, using GOGcli GUI, including full verification of all.

Every few days, I check to see if GOG have fixed the issue with Dying Light: The Following (Enhanced Edition), which still hasn't happened. I will likely do the same with the Gimrock games, which I have only just bought.

EDIT
Card Shark Demo is another one, that was brought back to mind today. The MAC file data cannot be retrieved, preventing the manifest from being added with GOGcli GUI. I was able to get the Windows game file data though, using GetGameInfo.

GetGameInfo v2.2 is now available.

Further improvements again.

DOWNLOAD & INFO - https://github.com/Twombs/GOGcli-GUI/releases/tag/v2.2g

EARLIER RELEASES & SCREENSHOTS - https://github.com/Twombs/GOGcli-GUI/releases

IMPORTANT - See details from previous posts of mine above.

The Warhammer Skulls 2022 - Digital Goodies Pack is another add to manifest failure, and even using my GetGameInfo program didn't help much, as the resulting download links were incorrect, and therefor file sizes are wrong. The correct links are the browser download links. I was able to manually edit the created manifest to have the downloads work, but files size validation failed of course for the zip files, though the zips themselves passed zip testing. At least the related free game, Warhammer 40,000: Chaos Gate, was added to the manifest without issue and all files downloaded fine.

EDIT
Card Shark Demo now adds to the manifest, so is fixed, though the installer file has been updated.
Legend of Grimrock and Legend of Grimrock 2 have been fixed too, and now add to the manifest.

No change with Dying Light: The Following (Enhanced Edition), that hasn't been fixed yet, still fails to update the manifest.

Another add to manifest failure for me - Man O' War: Corsair - Warhammer Naval Battles

EDIT
Once again my GetGameInfo program came to the rescue, getting data for all the Windows downloads for the game, just failing for the MAC download(s). That MAC error being enough to prevent addition to the manifest using my GOGcli GUI program.

Been somewhat hectic at work. Some complicated integration.

I'll get down to applying the workaround at the api level, but realistically, it might be anywhere between 1-4 more weeks.

No problem and no worries. I look forward to the result.

As usual I am just having a play around and seeing if I can come up with anything useful ... added extra sort of thing.

Right now I am having trouble grabbing multiple download links in one go via the browser for downloads in my GOG library. So unless I solve that, it may be just drag & drop per link onto a floating dropbox ... or copy & paste of each, so my program won't be quite as I hoped ... still useful though. I could do a web page save & scrape, but that's a bit b-grade.