Response format

Most endpoints can return data either as JSON or CSV. The default is JSON. To get a CSV, specify the query parameter dataFormat=csv.

Responses returned in JSON have three top level attributes:

  • “info” - data about the API itself

  • “errors” - an array (hopefully empty!) of things that went wrong

  • “data” - the actual response data



Genomic sequences (fasta and fasta-aligned endpoints) are returned in the FASTA format.


Every response, independent of the data format, contains the data version as it is a very important information. See the data versions page for details.