Hi,
Sorry for the delay - it looks like Firebase changed their API so I've had to change the libs which are in the latest release on my github.
If you search for NestBinding you should see more log lines.
In particular:
06:20:24.864 INFO o.o.b.n.internal.NestBinding[:105]- Creating Nest API Binding for clientId[XXX] clientSecret[YYY]
06:20:24.864 INFO o.o.b.n.internal.NestBinding[:106]- Binding started but not connected waiting for code from Nest website
06:20:24.866 INFO o.o.b.n.internal.NestBinding[:109]- Then set the code state in Openhab
06:20:24.866 INFO o.o.b.n.internal.NestBinding[:111]- Where "NestCode" is the name of the Nest code type in your item file
06:20:24.944 INFO o.o.c.s.AbstractActiveService[:169]- Nest Refresh Service has been started
That being said watou is out now as well and has been in development a lot longer than this months vs a handful of days so that might be stable.
In answer to your question mine doesn't use polling and doesn't store the code in the openhab.cfg file. As far as I know the code has to be changed every 2 days which is why I've gone with the approach of setting it as a variable in Openhab to make it easy to update (essentially what the instructions above are saying).
Hope that helps,
Neil