# Fatiando Development Calls 2026

📱 **Join the video call:** https://meet.jit.si/fatiando-a-terra

📅 **Shared calendar:** https://www.fatiando.org/calendar

> **IMPORTANT**: Everyone is required to follow our
> [Code of Conduct](https://github.com/fatiando/community/blob/main/CODE_OF_CONDUCT.md)
> when participating in the Fatiando community. Please review it carefully.

Development calls are **open to everyone**! Here we discuss project development, socialize, and do some live coding from time to time.

**Everyone is encouraged to participate and edit the notes below.**

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## Next meeting

## 2026-05-06

### Participants

* Matt
* Leo
* Arthur

### Notes

* Mostly just chatting
* State of xrft in Harmonica
* Review of the draft AI policy https://github.com/fatiando/community/pull/177

## 2026-04-22

### Participants

* Santi
*

### Notes

Policy on Generative AI usage:

* Started a draft in https://github.com/fatiando/community/pull/177
* Discuss policy on usage of genAI tools in code review.
* Santi would like to forbid using genAI tools to write the code review. But there are a few acceptable uses: writing a snippet to show an example, add extra tests, fix grammar. Basically, all accepted uses for developing code and writing documentation.
* We should improve that sentence.
* The text might be too long. Should we trim it?

Potential issue with xrft and next Harmonica release:

* https://github.com/fatiando/harmonica/issues/646
* Santi would like to release Harmonica 0.8.0 this or next week.
* Should we remove the constrain on xrft as dependency for now? It's very unlikely that the issue will get solved upstream during this week.
* Should we implement our own ffts on dataarrays instead?
* Maybe we can remove the version constrain in the conda-forge feedstock instead?

## 2026-04-08

### Participants

* Santi
* Leo
* Arthur

### Notes

* Reviewing the Euler Inversion PR in Harmonica: https://github.com/fatiando/harmonica/pull/660
* Arthur wants to start coding in Fatiando. Wil probably start by adding spherical kernels for Choclo. Maybe finish Lu's PR: https://github.com/fatiando/choclo/pull/57

## 2026-03-25

### Participants

* Santi
* Leo

### Notes

* Verde v1.9.0 was released!
* Now we can get rid of pinning of sklearn in Harmonica's CI
* Idea for 2.0: in KNeighbors.predict weight the reduction by distance. That will make the predictions less dependent on the value of k.
* Boule got some love
* ruff, no codecov, python 3.13, src layout
* breaking change for new version: coordinates are now taken as a tuple. Specify what type of coordinates through the coordinate_system argument
* we will need to bump minimum version of boule in Harmonica

## 2026-03-11

### Participants

* Santi
* Leo
* Mariana

### Notes

- Thinking about applying for a fiscal host:
- Open Collective: https://documentation.opencollective.com/
- Choosing fiscal hosts:
- https://opencollective.com/opensource
- https://opencollective.com/numfocus (things to consider: https://pirsquared.org/blog/numfocus-concerns.html#NF-europe)
- https://opencollective.com/europe
- Do they need us to be based there?
- Example of coops: https://coop.planetary-research.org/

- AI usage in Fatiando: https://github.com/fatiando/community/issues/171
- No PRs from agents.
- Checklist item on PR template about AI use.
- Suspected AI generated PRs can be closed without lengthy justification.
- Contributions are for us to teach and train new contributors and not bots.
- Put summary of the policy in all the READMEs
- State preference about human-written code
- Copyright issues:
- License infringements without noticing
- US court saying that genAI products are not copyrightable
- Hardly going to be enforced
- Trust people to do the right thing.
- Talk about our position and how we envision Fatiando.
- Say we prefer no AI since we're about getting people together to work on things
- Add examples of acceptable uses for genAI
- Translation to English if you are not a native speaker
- Use AI to review your code
- Add section to general CONTRIBUTING.md and add sections with links to project READMEs and CONTRIBUTING files.

## 2026-02-25

### Participants

* Dom
* Tizian
* Santi
* Pascal

### Notes

Tizian, Pascal and Dom shared their progress on `pooch-doi`, the new package that will handle fetching files from DOI-based services, like DataVerse, Figshare and Zenodo.

Naming packages, ideas:

- `pooch-doi`
- `pooch-zenodo`
- `pooch-figshare`
- `pooch-dataverse`

Potentially, we could have more repositories for other data repositories.

Where do the new pooch-related packages live?
We could create repos in the fatiando organziation for them, and appoint Dom, and anyone else that would like to step in, as maintainers.

## 2026-01-28

### Participants

* Santi
* Collin Cronkite-Ratcliff

### Notes

> :mega: **Announcement** :mega:
> In case you missed it: Matt Tankersely has joined as Harmonica maintainer! Welcome! :raised_hands:

Harmonica:

- Created an `environment.yml` file used to build docs in GitHub Actions: https://github.com/fatiando/harmonica/pull/626
- Instead of collecting requirements from the `env` files with `dependente` for two main reasons: those packages have PyPI names (we needed to rename a few to get the right conda package, like `build` into `python-build`), and with this file we can constrain particular versions of the optional packages if anything stop working upstream.
- Had to constrain `sklearn` version to `<1.8.0` since `1.8.0` is making Verde to error out because of missing attribute. See https://github.com/fatiando/harmonica/pull/628.
- Fixed docs failing due to incompatibilty with Pandas 3.0.0
- The `DataFrame.ravel()` method got deprecated, so I patched the equivalent sources to use `np.ravel()` on the input data array instead. This way we also ensure that the ravelled data is always a Numpy array.

Verde:

- The `DummyEstimator` is failing with `sklearn==1.8.0` due to a missing attribute `__sklearn_tags__`. See https://github.com/fatiando/verde/issues/530
- Possible solution: make it a child of `sklearn.base.BaseEstimator`. See https://github.com/fatiando/verde/pull/531

Pooch:

- Merged a few PRs
- Better error messages when requests fail.
- Support for Python 3.14
- Patch to bypass (at one extent) Zenodo's rate limits. Pass a default Pooch's User-Agent when making requests.
- Still some issues with how DOI downloaders are designed. Hard to standardize all requests. First try in this PR: https://github.com/fatiando/pooch/pull/514
- Planning to release this/next week, so users can make use of these changes.

USGS:

- Collin mentioned that they'll work on a USGS open-source project to develop a workflow for processing potential field data.
- Mostly interested in gravity for now.
- They will use Fatiando for the underlying computations.
- Open to contribute back if there's some methods that would be nice to have in Fatiando.