There are several different ways to install the asdf package. Each is described in detail below.


The asdf package has several dependencies which are listed in the project’s build configuration pyproject.toml. All dependencies are available on pypi and will be automatically installed along with asdf.

Support for units, time, and transform tags requires an implementation of these types. One recommended option is the asdf-astropy package.

Optional support for lz4 compression is provided by the lz4 package.

Installing with pip

Stable releases of the ASDF Python package are registered at PyPi. The latest stable version can be installed using pip:

$ pip install asdf

Installing with conda

asdf is also distributed as a conda package via the conda-forge channel. It is also available through the astroconda channel.

To install asdf within an existing conda environment:

$ conda install -c conda-forge asdf

To create a new conda environment and install asdf:

$ conda create -n new-env-name -c conda-forge python asdf

Building from source

The latest development version of ASDF is available from the main branch on github. To clone the project:

$ git clone

To install:

$ cd asdf
$ pip install .

To install in development mode:

$ pip install -e .

Running the tests

To install the test dependencies from a source checkout of the repository:

$ pip install -e ".[tests]"

To run the unit tests from a source checkout of the repository:

$ pytest

It is also possible to run the test suite from an installed version of the package.

$ pip install "asdf[tests]"
$ pytest --pyargs asdf

It is also possible to run the tests using tox.

$ pip install tox

To list all available environments:

$ tox -va

To run a specific environment:

$ tox -e <envname>