1. Login at https://graph.api.smartthings.com/
2. Navigate: My SmartApps > New SmartApp > From Code (tab)
3. Paste contents of rest-api.groovy
4. Click: Create, Publish > For Me
5. Navigate: App Settings > OAuth
6. Click: Enable OAuth in Smart App
7. Note the Client ID (i.e. abc123) and Client Secret (i.e. def321)

1. Replace the client_id value and open this URL in a browser: https://graph.api.smartthings.com/oauth/confirm_access?response_type=code&scope=app&redirect_uri=http%3A%2F%2Flocalhost&client_id=abc123
2. Login and Click "Authorize".
3. You will be redirected to http://localhost; note the code query value (i.e. aD4kF5 in http://localhost/?code=aD4kF5)
4. Run curl -v -H "Content-Type: application/x-www-form-urlencoded" -X POST --data 'grant_type=authorization_code&code=aD4kF5&client_id=abc123&client_secret=def321&redirect_uri=http%3A%2F%2Flocalhost' https://graph.api.smartthings.com/oauth/token
5. Note access_token in response (i.e. xyz123). This will be the access token used to authenticate to the REST API.
6. Run curl -v -H "Authorization: Bearer xyz123" https://graph.api.smartthings.com/api/smartapps/endpoints
7. Note the uri value (i.e. https://graph1.smartthings.com/api/smartapps/installations/123987). This will be the Endpoint URL used to access the REST API.

(Assumming Access Token: xyz123 and Endpoint URL: https://graph1.smartthings.com/api/smartapps/installations/123987)

curl -v -H "Authorization: Bearer xyz123" \
  https://graph1.smartthings.com/api/smartapps/installations/123987/devices

curl -v -H "Authorization: Bearer xyz123" \
  https://graph1.smartthings.com/api/smartapps/installations/123987/device/123/attribute/switch

curl -H "Authorization: Bearer xyz123" -X POST \
  https://graph1.smartthings.com/api/smartapps/installations/123987/device/123/command/on

curl -H "Authorization: Bearer xyz123" -X POST \
  https://graph1.smartthings.com/api/smartapps/installations/123987/device/123/command/off

curl -H "Authorization: Bearer xyz123" -X POST \
  https://graph1.smartthings.com/api/smartapps/installations/123987/device/123/command/setLevel?arg=50