The Short Time Historic (STH, aka. Comet) is a component of the FIWARE ecosystem in charge of managing (storing and retrieving) historical raw and aggregated time series information about the evolution in time of context data (i.e., entity attribute values) registered in an Orion Context Broker instance.
All the communications between the STH and the Orion Context Broker as well as between the STH and any third party (typically for data retrieval) use standardized NGSIv2 interfaces.
Documentation and API
Additional information and documentation about the Short Time Historic (STH) component can be obtained at the ReadTheDocs site of the component at http://fiware-sth-comet.readthedocs.io/en/latest/index.html as well as at its Github repository at https://github.com/telefonicaid/fiware-sth-comet.