Calibre Sync broken by Calibre v9?

[GeniusJ]

Originally Posted by ReadingEnjoyer

I emailed the developer of Calibre Sync. I hope he will fix it soon. The last update on Android was in April 2025. There is as far as I can tell, no alternative. I purchased Calibre Sync awhile ago and have relied on it extensively. I'm surprised it is the only program like it.

It's not the only program like it. A few messages back in this thread, someone pointed out Calibre View (although it won't read my Dropbox account correctly, so I can't properly test it).

[jbusnengo]

Originally Posted by GeniusJ

It's not the only program like it. A few messages back in this thread, someone pointed out Calibre View (although it won't read my Dropbox account correctly, so I can't properly test it).

That doesn't help those of us with Android devices.

[ReadingEnjoyer]

Originally Posted by jbusnengo

That doesn't help those of us with Android devices.

I use android. I found the original developer by name and emailed him too. He replied saying he no longer has any involvement. This doesn't seem like a good sign. I still haven't received a reply from the official developer email.

calibre.sync.help@gmail.com is their official support email.

[GeniusJ]

I posted a Windows Powershell script which fixes it for me. It adds the 3 columns back to the db file, and only needs to be run once after every time Calibre updates and drops the tables again. Just quit Calibre, run the powershell, and viola the columns are back until the next time Calibre updates. My post is in another thread about this.

[PeterT]

Originally Posted by GeniusJ

I posted a Windows Powershell script which fixes it for me. It adds the 3 columns back to the db file, and only needs to be run once after every time Calibre updates and drops the tables again. Just quit Calibre, run the powershell, and viola the columns are back until the next time Calibre updates. My post is in another thread about this.

calibre will NOT drop the columns on each upgrade. The DB updates are based on the USER_VERSION stored in the database. If the upgrade contains a newer version than the actual database the required code is run once and the database USER_VERSION updated to reflect that change.

[GeniusJ]

Oh cool, then in that case it sounds like maybe the script only needs to be updated once. I like one and done.

[VelvetElvis]

Originally Posted by ReadingEnjoyer

I still haven't received a reply from the official developer email.

calibre.sync.help@gmail.com is their official support email.

I emailed him right after the issue came up, and provided information on the fields in question. No response. Mailed him again Saturday, and said if he's not going to fix it, then he should at least pull it from The Play Store so people won't get burned buying a broken app. Of course, no response to that either.

[xyris]

Originally Posted by GeniusJ

I posted a Windows Powershell script which fixes it for me. It adds the 3 columns back to the db file, and only needs to be run once after every time Calibre updates and drops the tables again. Just quit Calibre, run the powershell, and viola the columns are back until the next time Calibre updates. My post is in another thread about this.

Sorry if this is a stupid question, but WHERE did you post your PowerShell script? I'd like to try it, if you allow.

Alternatively, could someone post instructions for the computer-adventurous like me, who are willing to learn, but need guidance with such technical stuff like editing metadata.db to restore CS functionality?

Thanks a lot!

[DNSB]

Originally Posted by xyris

Sorry if this is a stupid question, but WHERE did you post your PowerShell script? I'd like to try it, if you allow.

Check message #328 in the Calibre Sync for Android & iOS thread.

[jtmart]

I am tempted to run @Glsparks2 script @GeniusJ's script, but also feel slightly reluctant to do so because I have several* instances relying on my Calibre's main DB with 7k entries.

Is there evidence that @kovidgoyal (or goodwillers) is/are willing to work on a fix to be implemented in Calibre 9.x? If so, I am more than happy to wait 2-3 months rather than alter right now the DB from outside Calibre...

--

*Calibre Synç on five devices, Calibre Server for my uni. students, Calibre View, four Powershell scripts to monitor various two-way syncs with my Android readers, etc.

[kovidgoyal]

I am not going to be fixing this in calibre. As I have explained elsewhere metadata.db is *private to calibre*. Third party applications should not rely on it being unchanged. If an application such as calibre sync wants to use metadata.db then it is very much on it to ensure it handles changes to the database schema. Indeed given that calibre sync appears to be unmaintained, I would discourage anyone from relying on it since as metadata.db and other parts of calibre change over time, it is quite likely calibre sync will either break or worse corrupt data.

[Josieb1]

Originally Posted by VelvetElvis

I emailed him right after the issue came up, and provided information on the fields in question. No response. Mailed him again Saturday, and said if he's not going to fix it, then he should at least pull it from The Play Store so people won't get burned buying a broken app. Of course, no response to that either.

It’s annoying that this is the second paid for app that gave me calibre information on a phone or tablet that has ended up a waste of money. Ironically I’d have been happy paying a subscription for calibre sync but the developer has walked away.

[jtmart]

Originally Posted by kovidgoyal

I am not going to be fixing this in calibre. As I have explained elsewhere metadata.db is *private to calibre*. Third party applications should not rely on it being unchanged. If an application such as calibre sync wants to use metadata.db then it is very much on it to ensure it handles changes to the database schema. Indeed given that calibre sync appears to be unmaintained, I would discourage anyone from relying on it since as metadata.db and other parts of calibre change over time, it is quite likely calibre sync will either break or worse corrupt data.

Thanks a ton for clarifying things out @kovidgoyal, this saves folks in this thread from waiting for Calibre or Calibre Sync updates that would fix the issue. I guess you are also dissuading us from manually altering the Calibre DB or doing a rollback to version 8.x.

This leaves me a bit concerned about the future of Android companions apps to Calibre, as no actively maintained project seems to currently exist. It is a bit of a missed opportunity; with the death of CS and Calibre Companion (have not yet tried JetReader which is in alpha I think), there is clearly a vacuum as many e‑reader manufacturers move to platforms that allow APK side-loading and/or provide Google Play access.

Accessing Calibre‑synced cloud files directly on my e‑reader is extremely convenient and suits my reading workflow best. Alternatives (I mainly use Dropsync) either require input on your main PC or to sync everything, which is not feasible/reasonable for even medium-sized digital libraries. The in-built Calibre server is truly excellent, but many institutions (like my uni) limit port opening/tunneling on their networks, so I can't easily access my books' catalogue remotely from my e-ink devices.

Just my two cents, but without a viable companion app, Android e-readers with a remote Calibre integration cannot be leveraged to their full potential...

[mitra1]

Many times i donated money to Kovid Goyal, but i never understood why there isn't an android version or an api that third party developers can use. Android is the most used operating system more than windows so i think it's reasonable that many people would want access to their library directly on smartphone or tablet/chromebook.

[BetterRed]

Sheesh - I see the Age of Entitlement is alive and well, thriving even.

Any Android or IOS developer who wants to leverage (make money from) Kovid Goyal's Free Open Source Software should do whatever it takes to monitor what's happening here, at Github, and Launchpad etc. The fact that they don't or even worse they fold their tent and head off into the sunset without so much as a 'thank your Mum for the rabbits' is down to them.

Same for users, products such as calibre-synch are of no use without access to a calibre library… which can only be created and maintained by Kovid Goyal's calibre software on Linux, MacOS, and Windows.

BR