An event category is a group of different kind of context information. This can be ACTIVITY, BIO or ENVIRONMENT. The categories aren't supposed to be changed. Categories can be used as a filter for requesting context models.

Yes, please take a look at Authentication. To keep it simple, only the data parameter is mentioned on this page, but keep in mind that the other parameters are also necessary.

JSON

GET

http://api.learning-context.de/3/env/categories

The JSON object data is not necessary here since there is no need to transfer any parameters.

data={
}

{
   "APIVersion":3,
   "result":1,
   "categories":[
      "ACTIVITY",
      "BIO",
      "ENVIRONMENT"
   ]
}

In case of an error, a different response is sent. Please take a look at Error Responses.