How to package plugins#

This section focuses on how to package AiiDA extensions (plugins) so that they can be tested, published and eventually reused by others.

Creating a plugin package#

AiiDA plugins can be bundled and distributed in a Python package that provides a set of extensions to AiiDA.


The Python community uses the term ‘package’ rather loosely. Depending on context, it may refer simply to a folder containing individual Python modules or it may include the files necessary for building and installing a package to be distributed via the Python Package Index (PyPI).


The fastest way to jumpstart an AiiDA plugin package is to use the AiiDA plugin cutter in order to template the basic folder structure, already customized according to the desired name of your plugin, following AiiDA conventions.

Simply go to the AiiDA plugin cutter and follow the usage instructions. See also the aiida-diff demo plugin package for an in-depth explanation of the files & folders produced by the plugin cutter.

In the following, we explain some of the conventions implemented by the AiiDA plugin cutter.

Choosing a name#

The naming convention for AiiDA plugin packages is aiida-mycode for the plugin distribution on PyPI and aiida_mycode for the corresponding python package, leading to the following folder structure:



Python package names cannot contain dashes, thus the underscore.

If you intend to eventually publish your plugin package, please go to the AiiDA plugin registry and choose a name that is not already taken. You are also encouraged to pre-register your package (instructions provided on the registry), both to reserve your plugin name and to inform others of your ongoing development.

Folder structure#

The overall folder structure of your plugin is up to you, but it is useful to follow a set of basic conventions. Here is an example of a folder structure for an AiiDA plugin, illustrating different levels of nesting (see also the aiida-diff demo plugin):

aiida-mycode/           - distribution folder
   aiida_mycode/        - top-level package (from aiida_mycode import ..)
      calculations/      - contains MycodeCalculation
      parsers/       - contains BasicMycodeParser        - contains FullMycodeParser
      data/    - contains code-specific MyData data format       - contains verdi subcommand for visualizing MyData
      workflows/       - contains a basic workflow using mycode
   LICENSE              - license of your plugin          - lists non-python files to be installed, such as LICENSE            - project description for github and PyPI
   pyproject.toml       - plugin metadata: installation requirements, author, entry points, etc.

A minimal plugin package instead might look like:


Registering plugins through entry points#

An AiiDA plugin is an extension of AiiDA that announces itself by means of a new entry point (for details, see What is an entry point?). Adding a new entry point consists of the following steps:

  1. Deciding a name. We strongly suggest to start the name of each entry point with the name of the plugin package (omitting the ‘aiida-’ prefix). For a package aiida-mycode, this will usually mean "mycode.<something>"

  2. Finding the right entry point group. You can list the entry point groups defined by AiiDA via verdi plugin list. For a documentation of the groups, see AiiDA entry point groups.

  3. Adding the entry point to the entry_points field in the pyproject.toml file:

    "mycode.<something>" = "aiida_mycode.calcs.some:MysomethingCalculation"

Your new entry point should now show up in verdi plugin list aiida.calculations.


Taking a package with the name aiida-diff as example, what does pip install aiida-diff do?

  • It resolves and installs the dependencies on other python packages

  • It creates a folder aiida_diff.egg-info/ with metadata about the package

  • If the -e option is given, a symbolic link from the python package search path to the aiida-diff directory is created and the .egg-info folder is put there instead. Changes to the source code will be picked up by python without reinstalling (when restarting the interpreter), but changes to the metadata will not.

For further details, see the Python packaging user guide.

Testing a plugin package#

Writing tests for your AiiDA plugins and running continuous integration tests using free platforms like GitHub Actions is the best way to ensure that your plugin works and keeps working as it is being developed. We recommend using the pytest framework for testing AiiDA plugins.

For an example of how to write tests and how to set up continuous integration, see the aiida-diff demo plugin package.

Folder structure#

We suggest the following folder structure for including tests in AiiDA plugin packages:

aiida-mycode/           - distribution folder
   aiida_mycode/        - plugin package
   tests/               - tests directory (possibly with subdirectories)


Keeping the tests outside the plugin package keeps the distribution of your plugin package light.

AiiDA’s fixtures#

Many tests require a full AiiDA environment to be set up before the test starts, e.g. some AiiDA data nodes. The pytest library has the concept of fixtures for encapsulating code you would like to run before a test starts. AiiDA ships with a number of fixtures in that take care of setting up the test environment for you (for more details, see Plugin test fixtures).

In order to make these fixtures available to your tests, create a (see also pytest docs) at the root level of your plugin package as follows:

import pytest
pytest_plugins = ''  # make AiiDA's fixtures available
# tip: look inside to see which fixtures are provided

By importing AiiDA’s fixtures, the aiida_profile fixture gets used automatically, which takes care that a test profile is created and loaded. The profile (and configuration directory in which it is hosted) is only temporary and is automatically removed after the test session finished. This ensures that any production profiles on the system are not affected by the tests.

Other fixtures have to be explicitly used in a test to be of use. They usually allow creating some resources that are required by the test, such as a Code node:

def test_calculation(aiida_code_installed):

“””Test running a calculation using a CalcJob plugin.””” from aiida.engine import run

code = aiida_code_installed(default_calc_job_plugin=’core.arithmetic.add’, filepath_executable=’/bin/bash’) builder = code.get_builder() builder.x = orm.Int(1) builder.y = orm.Int(2)

results, node = run.get_node(builder)

assert node.is_finished_ok assert results[‘sum’] == 3

In order to run your tests, simply type pytest at the root level or your package. pytest automatically discovers and executes files, classes and function names starting with the word test.

Documenting a plugin package#

AiiDA plugin packages are python packages, and general best practises for writing python documentation apply.

In the following, we mention a few hints that apply specifically to AiiDA plugins.

Repository-level documentation#

Since the source code of most AiiDA plugins is hosted on GitHub, the first contact of a new user with your plugin package is likely the landing page of your GitHub repository.

  • Make sure to have a useful, describing what your plugin does and how to install it.

  • Leaving a contact email and adding a license is also a good idea.

  • Make sure the information in the pyproject.toml file is correct and up to date (in particular the version number), since this information is used to advertise your package on the AiiDA plugin registry.

Source-code-level documentation#

Source-code level documentations matters both for users of your plugin’s python API and, particularly, for attracting contributions from others.

When adding new types of calculations or workflows, make sure to use docstrings, and use the help argument to document input ports and output ports. Users of your plugin can then inspect which inputs the calculations/workflows expect and which outputs they produce directly through the verdi cli. For example, try:

verdi plugin list aiida.calculations core.arithmetic.add

Documentation website#

For simple plugins, a well-written can be a good start. Once the README grows out of proportion, you may want to consider creating a dedicated documentation website.

The Sphinx tool makes it very easy to create documentation websites for python packages, and the ReadTheDocs service will host your sphinx documentation online for free. The aiida-diff demo plugin comes with a full template for a sphinx-based documentation, including a mix of manually written pages and an automatically generated documentation of your plugin’s python API. See the developer guide of aiida-diff for instructions on how to build it.

AiiDA provides a sphinx extension for inserting automatically generated documentations of Process classes (calculations and workflows) into your sphinx documentation (analogous to the information displayed by verdi plugin list). Enable the extension by adding aiida.sphinxext to the list of extensions in your docs/ file. You can now use the aiida-process, aiida-calcjob or aiida-workchain directives in your ReST files like so:

.. aiida-workchain:: MyWorkChain
    :module: my_plugin


  • MyWorkChain is the name of the workchain to be documented.

  • :module: is the python module from which the workchain can be imported.

  • :hide-unstored-inputs: hides workchain inputs that are not stored in the database (shown by default).


The aiida-workchain directive is hooked into sphinx.ext.autodoc, i.e. it is used automatically by the generic automodule, autoclass directives when applied to workchain classes.

Publishing a plugin package#

AiiDA plugin packages are published on the AiiDA plugin registry and the python package index (PyPI).

Before publishing your plugin, make sure your plugin comes with:

  • a pyproject.toml file with the plugin metadata and for installing your plugin via pip

  • a license

For examples of these files, see the aiida-diff demo plugin.

Publishing on the plugin registry#

The AiiDA plugin registry aims to be the home for all publicly available AiiDA plugins. It collects information on the type of plugins provided by your package, which AiiDA versions it is compatible with, etc.

In order to register your plugin package, simply go to the plugin registry and follow the instructions in the README.


The plugin registry reads the metadata of your plugin from the pyproject.toml file in your plugin repository.

We encourage you to get your plugin package listed as soon as possible, both in order to reserve the plugin name and to inform others of the ongoing development.

Publishing on PyPI#

For distributing AiiDA plugin packages, we recommend to follow the guidelines for packaging python projects, which include making the plugin available on the python package index. This makes it possible for users to simply pip install aiida-myplugin.