Output Schema Plugins


pycsw allows for extending the implementation of output schemas to the core standard. outputschemas allow for a client to request metadata in a specific format (ISO, Dublin Core, FGDC, NASA DIF Atom and GM03 are default).

All outputschemas must be placed in the pycsw/plugins/outputschemas directory.


  __init__.py # empty
    __init__.py # __all__ is a list of all provided outputschemas
    atom.py # default
    dif.py # default
    fgdc.py # default
    gm03.py # default

Implementing a new outputschema

Create a file in pycsw/plugins/outputschemas, which defines the following:

  • NAMESPACE: the default namespace of the outputschema which will be advertised
  • NAMESPACE: dict of all applicable namespaces to outputschema
  • XPATH_MAPPINGS: dict of pycsw core queryables mapped to the equivalent XPath of the outputschema
  • write_record: function which returns a record as an lxml.etree.Element object

Add the name of the file to __init__.py:__all__. The new outputschema is now supported in pycsw.


New outputschemas must add examples to the Tester interface, which must provide example requests specific to the profile.