diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..a19ade0
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1 @@
+CHANGELOG.md merge=union
diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS
new file mode 100644
index 0000000..0211a4e
--- /dev/null
+++ b/.github/CODEOWNERS
@@ -0,0 +1,6 @@
+# CODEOWNERS file
+
+# Protect workflow files
+/.github/ @theissenhelen @jesperdramsch @gmertes @b8raoult @floriankrb
+/.pre-commit-config.yaml @theissenhelen @jesperdramsch @gmertes @b8raoult @floriankrb
+/pyproject.toml @theissenhelen @jesperdramsch @gmertes @b8raoult @floriankrb
diff --git a/.github/ci-hpc-config.yml b/.github/ci-hpc-config.yml
new file mode 100644
index 0000000..cd11ba2
--- /dev/null
+++ b/.github/ci-hpc-config.yml
@@ -0,0 +1,8 @@
+build:
+  python: '3.10'
+  modules:
+    - ninja
+  parallel: 64
+
+  pytest_cmd: |
+    python -m pytest -vv -m 'not notebook and not no_cache_init' --cov=. --cov-report=xml
diff --git a/.github/workflows/changelog-pr-update.yml b/.github/workflows/changelog-pr-update.yml
new file mode 100644
index 0000000..73cb1eb
--- /dev/null
+++ b/.github/workflows/changelog-pr-update.yml
@@ -0,0 +1,18 @@
+name: Check Changelog Update on PR
+on:
+  pull_request:
+    types: [assigned, opened, synchronize, reopened, labeled, unlabeled]
+    branches:
+      - main
+      - develop
+    paths-ignore:
+      - .pre-commit-config.yaml
+      - .readthedocs.yaml
+jobs:
+  Check-Changelog:
+    name: Check Changelog Action
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: tarides/changelog-check-action@v2
+        with:
+          changelog: CHANGELOG.md
diff --git a/.github/workflows/changelog-release-update.yml b/.github/workflows/changelog-release-update.yml
new file mode 100644
index 0000000..17d9525
--- /dev/null
+++ b/.github/workflows/changelog-release-update.yml
@@ -0,0 +1,35 @@
+# .github/workflows/update-changelog.yaml
+name: "Update Changelog"
+
+on:
+  release:
+    types: [released]
+  workflow_dispatch: ~
+
+permissions:
+  pull-requests: write
+  contents: write
+
+jobs:
+  update:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+      with:
+        ref: ${{ github.event.release.target_commitish }}
+
+    - name: Update Changelog
+      uses: stefanzweifel/changelog-updater-action@v1
+      with:
+        latest-version: ${{ github.event.release.tag_name }}
+        heading-text: ${{ github.event.release.name }}
+
+    - name: Create Pull Request
+      uses: peter-evans/create-pull-request@v6
+      with:
+        branch: docs/changelog-update-${{ github.event.release.tag_name }}
+        title: '[Changelog] Update to ${{ github.event.release.tag_name }}'
+        add-paths: |
+          CHANGELOG.md
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..66bb35f
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,43 @@
+name: ci
+
+on:
+  # Trigger the workflow on push to master or develop, except tag creation
+  push:
+    branches:
+      - 'main'
+      - 'develop'
+    tags-ignore:
+      - '**'
+    paths:
+      - "src/**"
+      - "tests/**"
+
+  # Trigger the workflow on pull request
+  pull_request: ~
+
+  # Trigger the workflow manually installs
+  workflow_dispatch: ~
+
+  # Trigger after public PR approved for CI
+  pull_request_target:
+    types: [labeled]
+
+jobs:
+  # Run CI including downstream packages on self-hosted runners
+  downstream-ci:
+    name: downstream-ci
+    if: ${{ !github.event.pull_request.head.repo.fork && github.event.action != 'labeled' || github.event.label.name == 'approved-for-ci' }}
+    uses: ecmwf-actions/downstream-ci/.github/workflows/downstream-ci.yml@main
+    with:
+      anemoi-transform: ecmwf/anemoi-transform@${{ github.event.pull_request.head.sha || github.sha }}
+      codecov_upload: true
+    secrets: inherit
+
+   # Build downstream packages on HPC
+  downstream-ci-hpc:
+    name: downstream-ci-hpc
+    if: ${{ !github.event.pull_request.head.repo.fork && github.event.action != 'labeled' || github.event.label.name == 'approved-for-ci' }}
+    uses: ecmwf-actions/downstream-ci/.github/workflows/downstream-ci-hpc.yml@main
+    with:
+      anemoi-transform: ecmwf/anemoi-transform@${{ github.event.pull_request.head.sha || github.sha }}
+    secrets: inherit
diff --git a/.github/workflows/label-public-pr.yml b/.github/workflows/label-public-pr.yml
new file mode 100644
index 0000000..59b2bfa
--- /dev/null
+++ b/.github/workflows/label-public-pr.yml
@@ -0,0 +1,10 @@
+# Manage labels of pull requests that originate from forks
+name: label-public-pr
+
+on:
+  pull_request_target:
+    types: [opened, synchronize]
+
+jobs:
+  label:
+    uses: ecmwf-actions/reusable-workflows/.github/workflows/label-pr.yml@v2
diff --git a/.github/workflows/python-publish.yml b/.github/workflows/python-publish.yml
new file mode 100644
index 0000000..2cb554a
--- /dev/null
+++ b/.github/workflows/python-publish.yml
@@ -0,0 +1,27 @@
+# This workflow will upload a Python Package using Twine when a release is created
+# For more information see: https://help.github.com/en/actions/language-and-framework-guides/using-python-with-github-actions#publishing-to-package-registries
+
+name: Upload Python Package
+
+on:
+  release:
+    types: [created]
+
+jobs:
+  quality:
+    uses: ecmwf-actions/reusable-workflows/.github/workflows/qa-precommit-run.yml@v2
+    with:
+      skip-hooks: "no-commit-to-branch"
+
+  checks:
+    strategy:
+      matrix:
+        python-version: ["3.9", "3.10"]
+    uses: ecmwf-actions/reusable-workflows/.github/workflows/qa-pytest-pyproject.yml@v2
+    with:
+      python-version: ${{ matrix.python-version }}
+
+  deploy:
+    needs: [checks, quality]
+    uses: ecmwf-actions/reusable-workflows/.github/workflows/cd-pypi.yml@v2
+    secrets: inherit
diff --git a/.github/workflows/python-pull-request.yml b/.github/workflows/python-pull-request.yml
new file mode 100644
index 0000000..2185264
--- /dev/null
+++ b/.github/workflows/python-pull-request.yml
@@ -0,0 +1,23 @@
+# This workflow will upload a Python Package using Twine when a release is created
+# For more information see: https://help.github.com/en/actions/language-and-framework-guides/using-python-with-github-actions#publishing-to-package-registries
+
+name: Code Quality checks for PRs
+
+on:
+  push:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  quality:
+    uses: ecmwf-actions/reusable-workflows/.github/workflows/qa-precommit-run.yml@v2
+    with:
+      skip-hooks: "no-commit-to-branch"
+
+  checks:
+    strategy:
+      matrix:
+        python-version: ["3.9", "3.10"]
+    uses: ecmwf-actions/reusable-workflows/.github/workflows/qa-pytest-pyproject.yml@v2
+    with:
+      python-version: ${{ matrix.python-version }}
diff --git a/.github/workflows/readthedocs-pr-update.yml b/.github/workflows/readthedocs-pr-update.yml
new file mode 100644
index 0000000..dfdd4f5
--- /dev/null
+++ b/.github/workflows/readthedocs-pr-update.yml
@@ -0,0 +1,22 @@
+name: Read the Docs PR Preview
+on:
+  pull_request_target:
+    types:
+      - opened
+      - synchronize
+      - reopened
+    # Execute this action only on PRs that touch
+    # documentation files.
+    paths:
+      - "docs/**"
+
+permissions:
+  pull-requests: write
+
+jobs:
+  documentation-links:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: readthedocs/actions/preview@v1
+        with:
+          project-slug: "anemoi-transform"
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..d4a8551
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,189 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+# .python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# poetry
+#   Similar to Pipfile.lock, it is generally recommended to include poetry.lock in version control.
+#   This is especially recommended for binary packages to ensure reproducibility, and is more
+#   commonly ignored for libraries.
+#   https://python-poetry.org/docs/basic-usage/#commit-your-poetrylock-file-to-version-control
+#poetry.lock
+
+# pdm
+#   Similar to Pipfile.lock, it is generally recommended to include pdm.lock in version control.
+#pdm.lock
+#   pdm stores project-wide configurations in .pdm.toml, but it is recommended to not include it
+#   in version control.
+#   https://pdm.fming.dev/#use-with-ide
+.pdm.toml
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.envrc
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# PyCharm
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+#.idea/
+
+*.grib
+*.onnx
+*.ckpt
+*.swp
+*.npy
+*.download
+?
+?.*
+foo
+bar
+*.grib
+*.nc
+*.npz
+*.json
+*.zarr/
+~$images.pptx
+test.py
+cutout.png
+*.out
+
+_build/
+?
+?.*
+~*
+*.sync
+_version.py
+*.code-workspace
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000..cbb03cb
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,87 @@
+repos:
+# Empty notebookds
+- repo: local
+  hooks:
+  - id: clear-notebooks-output
+    name: clear-notebooks-output
+    files: tools/.*\.ipynb$
+    stages: [commit]
+    language: python
+    entry: jupyter nbconvert --ClearOutputPreprocessor.enabled=True --inplace
+    additional_dependencies: [jupyter]
+- repo: https://github.com/pre-commit/pre-commit-hooks
+  rev: v4.6.0
+  hooks:
+  - id: check-yaml # Check YAML files for syntax errors only
+    args: [--unsafe, --allow-multiple-documents]
+  - id: debug-statements # Check for debugger imports and py37+ breakpoint()
+  - id: end-of-file-fixer # Ensure files end in a newline
+  - id: trailing-whitespace # Trailing whitespace checker
+  - id: no-commit-to-branch # Prevent committing to main / master
+  - id: check-added-large-files # Check for large files added to git
+  - id: check-merge-conflict # Check for files that contain merge conflict
+-   repo: https://github.com/pre-commit/pygrep-hooks
+    rev: v1.10.0  # Use the ref you want to point at
+    hooks:
+    -   id: python-use-type-annotations # Check for missing type annotations
+    -   id: python-check-blanket-noqa # Check for # noqa: all
+    -   id: python-no-log-warn # Check for log.warn
+- repo: https://github.com/psf/black-pre-commit-mirror
+  rev: 24.8.0
+  hooks:
+  - id: black
+    args: [--line-length=120]
+- repo: https://github.com/pycqa/isort
+  rev: 5.13.2
+  hooks:
+  - id: isort
+    args:
+    - -l 120
+    - --force-single-line-imports
+    - --profile black
+- repo: https://github.com/astral-sh/ruff-pre-commit
+  rev: v0.6.4
+  hooks:
+  - id: ruff
+    # Next line if for documenation cod snippets
+    exclude: '.*/[^_].*_\.py$'
+    args:
+    - --line-length=120
+    - --fix
+    - --exit-non-zero-on-fix
+    - --preview
+- repo: https://github.com/sphinx-contrib/sphinx-lint
+  rev: v1.0.0
+  hooks:
+  - id: sphinx-lint
+# For now, we use it. But it does not support a lot of sphinx features
+- repo: https://github.com/dzhu/rstfmt
+  rev: v0.0.14
+  hooks:
+  - id: rstfmt
+    exclude: 'cli/.*' # Because we use argparse
+- repo: https://github.com/b8raoult/pre-commit-docconvert
+  rev: "0.1.5"
+  hooks:
+  - id: docconvert
+    args: ["numpy"]
+- repo: https://github.com/tox-dev/pyproject-fmt
+  rev: "2.2.3"
+  hooks:
+  - id: pyproject-fmt
+-   repo: https://github.com/jshwi/docsig # Check docstrings against function sig
+    rev: v0.60.1
+    hooks:
+    -   id: docsig
+        args:
+        - --ignore-no-params # Allow docstrings without parameters
+        - --check-dunders    # Check dunder methods
+        - --check-overridden # Check overridden methods
+        - --check-protected  # Check protected methods
+        - --check-class      # Check class docstrings
+        - --disable=E113     # Disable empty docstrings
+        - --summary          # Print a summary
+ci:
+  autoupdate_schedule: monthly
+ci:
+  autoupdate_schedule: monthly
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
new file mode 100644
index 0000000..06c8ab4
--- /dev/null
+++ b/.readthedocs.yaml
@@ -0,0 +1,16 @@
+version: 2
+
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.11"
+
+sphinx:
+  configuration: docs/conf.py
+
+python:
+   install:
+    - method: pip
+      path: .
+      extra_requirements:
+        - docs
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..063481c
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,9 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+Please add your functional changes to the appropriate section in the PR.
+Keep it human-readable, your future self will thank you!
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..261eeb9
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
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+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
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+      designated in writing by the copyright owner as "Not a Contribution."
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+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
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+   3. Grant of Patent License. Subject to the terms and conditions of
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+      or contributory patent infringement, then any patent licenses
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+   4. Redistribution. You may reproduce and distribute copies of the
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+      meet the following conditions:
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+      (a) You must give any other recipients of the Work or
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+
+      (b) You must cause any modified files to carry prominent notices
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+
+      (c) You must retain, in the Source form of any Derivative Works
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+      (d) If the Work includes a "NOTICE" text file as part of its
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+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
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+   6. Trademarks. This License does not grant permission to use the trade
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+
+   7. Disclaimer of Warranty. Unless required by applicable law or
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+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
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+      other commercial damages or losses), even if such Contributor
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+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
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+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..2aaccba
--- /dev/null
+++ b/README.md
@@ -0,0 +1,42 @@
+# anemoi-transform
+
+**DISCLAIMER**
+This project is **BETA** and will be **Experimental** for the foreseeable future.
+Interfaces and functionality are likely to change, and the project itself may be scrapped.
+**DO NOT** use this software in any project/software that is operational.
+
+Miscellanous data transformation functions for training data-driven weather forecasts.
+
+## Documentation
+
+The documentation can be found at https://anemoi-transform.readthedocs.io/.
+
+## Install
+
+Install via `pip` with:
+
+```
+$ pip install anemoi-transform
+```
+
+## License
+
+```
+Copyright 2022, European Centre for Medium Range Weather Forecasts.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+In applying this licence, ECMWF does not waive the privileges and immunities
+granted to it by virtue of its status as an intergovernmental organisation
+nor does it submit to any jurisdiction.
+```
diff --git a/docs/Makefile b/docs/Makefile
new file mode 100644
index 0000000..6c0762a
--- /dev/null
+++ b/docs/Makefile
@@ -0,0 +1,22 @@
+#!/usr/bin/env make -f
+
+# Minimal makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line, and also
+# from the environment for the first two.
+SPHINXOPTS    ?=
+SPHINXBUILD   ?= sphinx-build
+SOURCEDIR     = .
+BUILDDIR      = _build
+
+# Put it first so that "make" without argument is like "make help".
+help:
+	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+
+.PHONY: help Makefile
+
+# Catch-all target: route all unknown targets to Sphinx using the new
+# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
+%: Makefile
+	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
diff --git a/docs/_static/logo.png b/docs/_static/logo.png
new file mode 100644
index 0000000..f78572e
Binary files /dev/null and b/docs/_static/logo.png differ
diff --git a/docs/_static/style.css b/docs/_static/style.css
new file mode 100644
index 0000000..9a2b3af
--- /dev/null
+++ b/docs/_static/style.css
@@ -0,0 +1,48 @@
+.wy-side-nav-search {
+    background-color: #f7f7f7;
+}
+
+/*There is a clash between xarray notebook styles and readthedoc*/
+
+.rst-content dl.xr-attrs dt {
+    all: revert;
+    font-size: 95%;
+    white-space: nowrap;
+}
+
+.rst-content dl.xr-attrs dd {
+    font-size: 95%;
+}
+
+.xr-wrap {
+    font-size: 85%;
+}
+
+.wy-table-responsive table td, .wy-table-responsive table th {
+    white-space: inherit;
+}
+
+/*
+.wy-table-responsive table td,
+.wy-table-responsive table th {
+    white-space: normal !important;
+    vertical-align: top !important;
+}
+
+.wy-table-responsive {
+    margin-bottom: 24px;
+    max-width: 100%;
+    overflow: visible;
+} */
+
+/* Hide notebooks warnings */
+.nboutput .stderr {
+    display: none;
+}
+
+/*
+Set logo size
+*/
+.wy-side-nav-search .wy-dropdown > a img.logo, .wy-side-nav-search > a img.logo {
+    width: 200px;
+}
diff --git a/docs/_templates/.gitkeep b/docs/_templates/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/docs/conf.py b/docs/conf.py
new file mode 100644
index 0000000..02b57ba
--- /dev/null
+++ b/docs/conf.py
@@ -0,0 +1,126 @@
+# Configuration file for the Sphinx documentation builder.
+#
+# This file only contains a selection of the most common options. For a full
+# list see the documentation:
+# https://www.sphinx-doc.org/en/master/usage/configuration.html
+
+# -- Path setup --------------------------------------------------------------
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#
+import datetime
+import os
+import sys
+
+read_the_docs_build = os.environ.get("READTHEDOCS", None) == "True"
+
+sys.path.insert(0, os.path.join(os.path.abspath(".."), "src"))
+
+source_suffix = ".rst"
+master_doc = "index"
+pygments_style = "sphinx"
+html_theme_options = {"logo_only": True}
+html_logo = "_static/logo.png"
+
+
+# -- Project information -----------------------------------------------------
+
+project = "Anemoi Transform"
+
+author = "ECMWF"
+
+year = datetime.datetime.now().year
+if year == 2024:
+    years = "2024"
+else:
+    years = "2024-%s" % (year,)
+
+copyright = "%s, ECMWF" % (years,)
+
+try:
+    from anemoi.transform._version import __version__
+
+    release = __version__
+except ImportError:
+    release = "0.0.0"
+
+
+# -- General configuration ---------------------------------------------------
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = [
+    "sphinx.ext.todo",
+    "sphinx_rtd_theme",
+    "nbsphinx",
+    "sphinx.ext.graphviz",
+    "sphinx.ext.intersphinx",
+    "sphinx.ext.autodoc",
+    "sphinx.ext.napoleon",
+    "sphinxarg.ext",
+]
+
+# Add any paths that contain templates here, relative to this directory.
+# templates_path = ["_templates"]
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This pattern also affects html_static_path and html_extra_path.
+exclude_patterns = ["_build", "Thumbs.db", ".DS_Store", "'**.ipynb_checkpoints'"]
+
+intersphinx_mapping = {
+    "python": ("https://python.readthedocs.io/en/latest", None),
+    "anemoi-utils": (
+        "https://anemoi-utils.readthedocs.io/en/latest/",
+        ("../../anemoi-utils/docs/_build/html/objects.inv", None),
+    ),
+    "anemoi-datasets": (
+        "https://anemoi-datasets.readthedocs.io/en/latest/",
+        ("../../anemoi-datasets/docs/_build/html/objects.inv", None),
+    ),
+    "anemoi-models": (
+        "https://anemoi-models.readthedocs.io/en/latest/",
+        ("../../anemoi-models/docs/_build/html/objects.inv", None),
+    ),
+    "anemoi-training": (
+        "https://anemoi-training.readthedocs.io/en/latest/",
+        ("../../anemoi-training/docs/_build/html/objects.inv", None),
+    ),
+    "anemoi-inference": (
+        "https://anemoi-inference.readthedocs.io/en/latest/",
+        ("../../anemoi-inference/docs/_build/html/objects.inv", None),
+    ),
+    "anemoi-graphs": (
+        "https://anemoi-graphs.readthedocs.io/en/latest/",
+        ("../../anemoi-graphs/docs/_build/html/objects.inv", None),
+    ),
+    "anemoi-registry": (
+        "https://anemoi-registry.readthedocs.io/en/latest/",
+        ("../../anemoi-registry/docs/_build/html/objects.inv", None),
+    ),
+    "anemoi-transform": (
+        "https://anemoi-transform.readthedocs.io/en/latest/",
+        ("../../anemoi-transform/docs/_build/html/objects.inv", None),
+    ),
+}
+
+# -- Options for HTML output -------------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+html_theme = "sphinx_rtd_theme"
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ["_static"]
+html_css_files = ["style.css"]
+
+
+todo_include_todos = not read_the_docs_build
+
+autodoc_member_order = "bysource"  # Keep file order
diff --git a/docs/index.rst b/docs/index.rst
new file mode 100644
index 0000000..a32e88c
--- /dev/null
+++ b/docs/index.rst
@@ -0,0 +1,62 @@
+.. _anemoi-transform:
+
+.. _index-page:
+
+##############################################
+ Welcome to `anemoi-transform` documentation!
+##############################################
+
+.. warning::
+
+   This documentation is work in progress.
+
+*Anemoi* is a framework for developing machine learning weather
+forecasting models. It comprises of components or packages for preparing
+training datasets, conducting ML model training and a registry for
+datasets and trained models. *Anemoi* provides tools for operational
+inference, including interfacing to verification software. As a
+framework it seeks to handle many of the complexities that
+meteorological organisations will share, allowing them to easily train
+models from existing recipes but with their own data.
+
+This package provides a series of utility functions for used by the rest
+of the *Anemoi* packages.
+
+-  :doc:`installing`
+
+.. toctree::
+   :maxdepth: 1
+   :hidden:
+
+   installing
+
+*********
+ Modules
+*********
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   modules/*
+
+*****************
+ Anemoi packages
+*****************
+
+-  :ref:`anemoi-utils <anemoi-utils:index-page>`
+-  :ref:`anemoi-transform <anemoi-transform:index-page>`
+-  :ref:`anemoi-datasets <anemoi-datasets:index-page>`
+-  :ref:`anemoi-models <anemoi-models:index-page>`
+-  :ref:`anemoi-graphs <anemoi-graphs:index-page>`
+-  :ref:`anemoi-training <anemoi-training:index-page>`
+-  :ref:`anemoi-inference <anemoi-inference:index-page>`
+-  :ref:`anemoi-registry <anemoi-registry:index-page>`
+
+*********
+ License
+*********
+
+*Anemoi* is available under the open source `Apache License`__.
+
+.. __: http://www.apache.org/licenses/LICENSE-2.0.html
diff --git a/docs/installing.rst b/docs/installing.rst
new file mode 100644
index 0000000..1055752
--- /dev/null
+++ b/docs/installing.rst
@@ -0,0 +1,31 @@
+############
+ Installing
+############
+
+To install the package, you can use the following command:
+
+.. code:: bash
+
+   pip install anemoi-transform[...options...]
+
+The options are:
+
+-  ``dev``: install the development dependencies
+-  ``all``: install all the dependencies
+
+**************
+ Contributing
+**************
+
+.. code:: bash
+
+   git clone git@github.com:ecmwf/anemoi-transform.git
+   cd anemoi-transform
+   pip install .[dev]
+   pip install -r docs/requirements.txt
+
+You may also have to install pandoc on MacOS:
+
+.. code:: bash
+
+   brew install pandoc
diff --git a/docs/modules/placeholder.rst b/docs/modules/placeholder.rst
new file mode 100644
index 0000000..68d1836
--- /dev/null
+++ b/docs/modules/placeholder.rst
@@ -0,0 +1,8 @@
+#############
+ placeholder
+#############
+
+.. automodule:: anemoi.transform.placeholder
+   :members:
+   :no-undoc-members:
+   :show-inheritance:
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..4dcaca3
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,71 @@
+#!/usr/bin/env python
+# (C) Copyright 2024 ECMWF.
+#
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+
+# https://packaging.python.org/en/latest/guides/writing-pyproject-toml/
+
+[build-system]
+requires = [ "setuptools>=60", "setuptools-scm>=8" ]
+
+[project]
+name = "anemoi-transform"
+
+description = "A package to hold various data transformation functions to support training of ML models on ECMWF data."
+keywords = [ "ai", "tools" ]
+
+license = { file = "LICENSE" }
+authors = [
+  { name = "European Centre for Medium-Range Weather Forecasts (ECMWF)", email = "software.support@ecmwf.int" },
+]
+
+requires-python = ">=3.9"
+
+classifiers = [
+  "Development Status :: 4 - Beta",
+  "Intended Audience :: Developers",
+  "License :: OSI Approved :: Apache Software License",
+  "Operating System :: OS Independent",
+  "Programming Language :: Python :: 3 :: Only",
+  "Programming Language :: Python :: 3.9",
+  "Programming Language :: Python :: 3.10",
+  "Programming Language :: Python :: 3.11",
+  "Programming Language :: Python :: 3.12",
+  "Programming Language :: Python :: Implementation :: CPython",
+  "Programming Language :: Python :: Implementation :: PyPy",
+]
+
+dynamic = [ "version" ]
+dependencies = [
+  "earthkit-data",
+  "earthkit-meteo",
+]
+
+optional-dependencies.all = [ "anemoi-transform" ]
+optional-dependencies.dev = [ "anemoi-transform[all,docs,tests]" ]
+
+optional-dependencies.docs = [
+  "nbsphinx",
+  "pandoc",
+  "requests",
+  "sphinx",
+  "sphinx-argparse<0.5",
+  "sphinx-rtd-theme",
+  "termcolor",
+]
+
+optional-dependencies.tests = [ "pytest" ]
+
+urls.Documentation = "https://anemoi-transform.readthedocs.io/"
+urls.Homepage = "https://github.com/ecmwf/anemoi-transform/"
+urls.Issues = "https://github.com/ecmwf/anemoi-transform/issues"
+urls.Repository = "https://github.com/ecmwf/anemoi-transform/"
+
+scripts.anemoi-transform = "anemoi.transform.__main__:main"
+
+[tool.setuptools_scm]
+version_file = "src/anemoi/transform/_version.py"
diff --git a/src/anemoi/transform/__init__.py b/src/anemoi/transform/__init__.py
new file mode 100644
index 0000000..7a799a1
--- /dev/null
+++ b/src/anemoi/transform/__init__.py
@@ -0,0 +1,9 @@
+# (C) Copyright 2024 European Centre for Medium-Range Weather Forecasts.
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+
+
+from ._version import __version__
diff --git a/src/anemoi/transform/__main__.py b/src/anemoi/transform/__main__.py
new file mode 100644
index 0000000..be940c2
--- /dev/null
+++ b/src/anemoi/transform/__main__.py
@@ -0,0 +1,28 @@
+#!/usr/bin/env python
+# (C) Copyright 2024 ECMWF.
+#
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+#
+
+from anemoi.utils.cli import cli_main
+from anemoi.utils.cli import make_parser
+
+from . import __version__
+from .commands import COMMANDS
+
+
+# For read-the-docs
+def create_parser():
+    return make_parser(__doc__, COMMANDS)
+
+
+def main():
+    cli_main(__version__, __doc__, COMMANDS)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/src/anemoi/transform/commands/__init__.py b/src/anemoi/transform/commands/__init__.py
new file mode 100644
index 0000000..cebb539
--- /dev/null
+++ b/src/anemoi/transform/commands/__init__.py
@@ -0,0 +1,24 @@
+#!/usr/bin/env python
+# (C) Copyright 2024 ECMWF.
+#
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+#
+
+import os
+
+from anemoi.utils.cli import Command
+from anemoi.utils.cli import Failed
+from anemoi.utils.cli import register_commands
+
+__all__ = ["Command"]
+
+COMMANDS = register_commands(
+    os.path.dirname(__file__),
+    __name__,
+    lambda x: x.command(),
+    lambda name, error: Failed(name, error),
+)
diff --git a/src/anemoi/transform/commands/hello.py b/src/anemoi/transform/commands/hello.py
new file mode 100644
index 0000000..793d126
--- /dev/null
+++ b/src/anemoi/transform/commands/hello.py
@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+# (C) Copyright 2024 ECMWF.
+#
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+#
+
+
+from . import Command
+
+
+class Hello(Command):
+
+    def add_arguments(self, command_parser):
+        command_parser.add_argument("--what", help="Say hello to someone")
+
+    def run(self, args):
+        if args.what:
+            print(f"Hello {args.what}!")
+        else:
+            print("Hello!")
+
+
+command = Hello
diff --git a/src/anemoi/transform/placeholder.py b/src/anemoi/transform/placeholder.py
new file mode 100644
index 0000000..1b4d478
--- /dev/null
+++ b/src/anemoi/transform/placeholder.py
@@ -0,0 +1,9 @@
+# (C) Copyright 2024 European Centre for Medium-Range Weather Forecasts.
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+
+
+# Remove this file when we have a few functions
diff --git a/tests/test_transform.py b/tests/test_transform.py
new file mode 100644
index 0000000..edacad9
--- /dev/null
+++ b/tests/test_transform.py
@@ -0,0 +1,17 @@
+# (C) Copyright 2024 European Centre for Medium-Range Weather Forecasts.
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+
+
+def test_transform():
+    pass
+
+
+if __name__ == "__main__":
+    for name, obj in list(globals().items()):
+        if name.startswith("test_") and callable(obj):
+            print(f"Running {name}...")
+            obj()