DAS protocol

The DAS protocol can be used to retrieve track data from a Distributed Annotation System (DAS) server. It supports DNA and region tracks, but not numeric tracks.

The protocol has two configurable settings: Base URL and Feature.

The Base URL should be set to the address of the DAS end-point, where the data for the track can be retrieved for a specific genome build. For DNA tracks this could for instance be something like "https://genome.ucsc.edu/cgi-bin/das/hg38/dna" for the "hg38" genome build. For region tracks, the base URL would usually end with "features" rather than "dna", e.g. "https://genome.ucsc.edu/cgi-bin/das/hg38/features".

The "Feature" setting is only used for region tracks (not for DNA tracks), and specifies the name of the tracks you want to retrieve. This value will be used as an added "type" argument when contacting the DAS server.