There is a REST API which allows pulling current sensor data
Take a look at This Tutorial
@Charles_Schwer created SmartApp that logs to Google Sheets which would be a good example on how to do it.
If you are logged into the IDE
You can go to https://graph.api.smartthings.com/api/hubs to get your hub id
Then go to https://graph.api.smartthings.com/api/hubs/idHashString/devices to get a list of devices
Then go to https://graph.api.smartthings.com/api/devices/idHashString/events to get recent events
The only problem with the ones in the box above is you have to be logged into the ide, there is no oauth for this. There used to be a loophole where you could use any oauth token on your account to get to this but it was closed recently for security reasons