Community Contributions

We aim to support the ecosystem of Databay users by collating and promoting third-party inlets and outlets that implement popular functionalities. We encourage you to share the inlets and outlets you write with the community. See the list of currently shared inlets and outlets, as well as the description of the submission process on Databay’s GitHub Page.


To ensure your contribution is widely adopted, we recommend the following guideline of implementation.

Read the documentation

Understand the design decisions behind Databay, and the inlets and outlets. Read through the examples as well as the currently implemented inlets and outlets to understand how Databay can be used.

Write tests

The more reliable your code is, the more likely other users will choose to rely on it. In this StackOverflow question you can read more about why tests matter. You can test some fundamental Databay functionality by using InletTester. You should write additional tests outside of scope of InletTester to cover the custom logic introduced by you. Remember that apart from writing unit tests, it is easy to write integration tests using Databay planners.

See to the tests of the built-in inlets and outlets for reference.

Write documentation

Your inlets and outlets should be well documented. Each implementation will be dependant on the functionality it provides, therefore your design decisions should be laid out and the API explained. We encourage you to write external standalone documentation apart from writing docstrings in code. Your GitHub page should also contain a short introduction, overview and examples.

Correctly use metadata


When writing inlets, remember to not modify or read the metadata provided, and to correctly initialise your inlet using super().__init__(*args, **kwargs).


class MyInlet(Inlet):

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.my_argument = self.metadata['my_argument']


class MyInlet(Inlet):

    def __init__(self, my_argument, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.my_argument = my_argument


When writing outlets supporting metadata, you should clearly describe the expected behaviour of each metadata in the documentation.

Your outlet should not exclusively rely on metadata and error out in its absence. Provide a method of setting default values for all metadata you expect and use these when encountering records that don’t carry metadata.

To prevent name clashing with other implementations, each metadata key should contain the name of your outlet included in its body.




FILEPATH:MetadataKey = 'CsvOutlet.FILEPATH'