Rated 3 out of 5 stars

Sadly this is history, but gContactSync works well.
gContactSync is being kept up to date and uses the now required OAuth2 - a more secure method of authentication that does not require application-specific passwords for accounts using 2-step authentication.

(Below TB means Thunderbird).

If you have this old Google Contacts installed, then 1st Uninstall it (via TB Tools menu/Add-ons and then select the old Google Contacts add-on and click Remove). Then open the TB Address book and rename the old Google address book to "old-something" or better yet, just delete it.

Then download and save the gContactSync xpi file from https://addons.mozilla.org/en-US/thunderbird/addon/gcontactsync/?src=search

[Note, if you block cookies in Firefox, then read the following link (If you do not understand what this means, then skip this step as the normal default Firefox settings work fine).see http://www.pirules.org/addons/gcontactsync/faq.php#cookies ]

Now install gContactsync as follows...

In TB, get to the Tools menu (Don't see it? try Alt-T) Open Add-ons from the Tools menu.
Near the top right of the screen, find the Options button (which is the gear shaped icon next to the "search all add-ons" field).
Click this Options (gear shaped) button and select "Install Add-on From File..." and locate the just downloaded gcontactSync add-on xpi file and select it. etc.
Let it install.
Restart TB.
It will ask how to set up - pick your Google email address from the drop down list (if not there then enter it). Take the default and create an address book named the same as your gmail address. This should be a new address book - if it is not, then change the name so it is new.

I told it to sync all groups and contacts, and told it to sink one way only - from Google to here. But the other options should work find. (I have seen suggestions to only sync the My Contacts group and not the group lists, but I find the group lists convenient.)

Now open TB's Address book - it may ask to login to Google. Do it. Give the complete Google email address. (It does not save the password).

It will now quickly set up a new TB address book for your Google contacts and sync it. You are all ready to go.

Rated 5 out of 5 stars

We need to save this addon as a community!!!

I would have fixed this by now if i knew how to code better! So github it??

Looks like google officially deprecated the old ClientLogin api.
as shown here

google now uses the new OAuth2 API and new API files.
as shown here

and just peaking into the gmcont.js file is see the following code for one...
var feedUrl = "https://www.google.com/accounts/ClientLogin";

i guess we just need to update all code to the new API and API files.??? doubt it'll be that simple.
problem is i think this new Oauth2 needs to be enabled via the developers admin console to use the new API.

so i guess its reworking it to work with a new account too

if only i had the skill.

gContactSync doesn't seem better than this if im honest.

try gContactSync instead Rated 3 out of 5 stars

It was good while it lasted.

There is another addon that looks even better: gContactSync. It seem to synchronize the full contact, including photos. I just started using it and it looks pretty good.

Rated 1 out of 5 stars

Lets fork!

fork Rated 3 out of 5 stars

wildstray, do it please. and post the repo link

Coders are humans so will we need to fork / recode the extension? Rated 1 out of 5 stars

Dear Ace Frahm, coders are human but this is an abondoned project. I tried to contact the author and he didn't reply me. HUNDREDS persons opened and updated tickets about the authentication, from months, without an answer.
Is this awful? Or is awful to leave persons with an extension used on daily basis not working from months?
And by the by, because I'm an awful person, I'm inclined to unpack the extension and fork it on github. At least the COMMUNITY could fix and carry on the project, seeing the lack of interest of the original author.

This user has a previous review of this add-on.

Coders Are Human, Humans Need Time To Code Rated 5 out of 5 stars

Give him some time to fix the recurring password dialog problem, it only just started happening, be patiient. Real human coders might take a few days to realize there's a problem, and a few more to fix it. Plus, he gets to have a summer vacation sometime too, and that might be now. So knock it off with your 1 or 2 star ratings, that's awful behavior.

Useless Rated 1 out of 5 stars

Doesn't work anymore and is useless until it gets fixed.
It may be Google's fault, but that's not relevant as long as it doesn't work.

Rated 4 out of 5 stars

Was fixed, but the log-in pop-up started happening again. Thunderbird 38.0.1, Google Contacts 0.7.12

Useless in secure environment with TorBirdy/TOR and TorBirdy/JonDo Rated Rated 1 out of 5 stars

Google Contacts 0.7.12 not working with Thunderbird & Enigmail & TorBirdy/TOR and TorBirdy/JonDo Anomynization

not working with Thunderbird & Enigmail & TorBirdy/TOR and TorBirdy/JonDo Anomynization

Working again Rated 5 out of 5 stars

I don't know what is happened, but now 11.06.2015 this add-on is working again. Problems with authentication are gone. The add-on version is the same, maybe Google has changed something once again :)

Problème avec Google Contacts 0.7.12 Rated 5 out of 5 stars

J'ai le même souci depuis une dizaine de jours: plus de synchronisation avec Google Contacts. Il demande toujours le mot de passe et même en le renseignant, la demande réapparaît sans être prise en compte...
Une mise à jour est-elle prévue?
Ce module est super sinon!!

OwnCloud Rated 4 out of 5 stars

Google changed API again... annoying. Possible fix: no longer use google contacts, use owncloud instead and regain control over your data....

problème authentification google contatcs Rated 2 out of 5 stars

J'ai un soucis avec la dernière version de Thunderbird. j'utilise le module complémentaire Google Contacts 0.7.12 pour synchroniser mon carnet d'adresse
avec Thunderbird et depuis 15 jours maintenant il refuse de prendre mon mot de passe en compte. j'ai supprimé le module et réinstallé, rien à faire.

A chaque fois que je redémarre TB il me redemande le mot de passe de google contact , je le met et il me le redemande sans cesse je dois faire annuler pour continuer

This user has 2 previous reviews of this add-on.

Не работает синхронизация контактов Rated 1 out of 5 stars

При запуске Thunderbird появляется окно аутентификации, пароль не принимается :(((

Same here. Google API change, doesn't work any more Rated 1 out of 5 stars

Same here. Google API change, doesn't work any more

Deprecated Rated 1 out of 5 stars

Goto : gContactSync

Switched to gContactSync Rated 1 out of 5 stars

JakeV - many thanks. I've installed gContactSync and it is working.

This user has a previous review of this add-on.

Same here. Google API change, doesn't work any more Rated 1 out of 5 stars

Used it for a long time, but since May 2015, it hasn't work, with an endless loop of windows requesting log on to Google Contacts despite using the correct account password and even the one time passwords in Google for accounts with 2-Step verification turned on.

Google Contacts does not work anymore Rated 1 out of 5 stars

For a week, the password is asked without stopping and without end.
No new developer!
I ended up leaving the "Add-on" and for those interested, replacing I took "gContactSync"