Update – This post is old and no longer applies as Logitech Harmony has now been officially supported in the UK for over 18 months now
Samsung have finally fixed the OAuth Problem for the Logitech Harmony UK Servers since SmartThings release in the UK its been a annoying process of making the Harmony work with SmartThings and to be honest it still is as Samsung takes ages to add compatible products to the UK marketplace so the only way is though the IDE.
User xAPPO Posted the following on the Samsung UK SmartThings Community two days ago
I added SmartThings to the Harmony iOS app first – selected my ST hub location and then enabled the devices I wanted. That worked OK (although it’s easy to overlook the spinner select for location at the bottom of the screen).
I then added the Logitech Harmony (Connect) SmartApp in the ST IDE ‘My SmartApps’ – enabled oAuth in the ‘App Settings’ and then ‘Publish’ (For me) … and then I did the same for the Logitech Harmony Hub C2C device in the Device Handlers and ‘Publish’ (For me). I did not have to edit either code in any way (for example to change the EU server address).
Then using the ST app via ‘My Apps’ in ‘SmartApps’ I entered my Harmony account details – it authorised (a bit slowly) and then found my hub and my activities (again a bit slowly) which I could then add to ST. My hub then appears as a device using my new device handler in the ST IDE and I have control from ST.