# 2026.04.21 Weekly Meeting

**URL:** <https://discourse.slicer.org/t/2026-04-21-weekly-meeting/46789>\
**Category:** Weekly meetings\
**Created:** [April 20, 2026, 5:27pm UTC](https://discourse.slicer.org/t/2026-04-21-weekly-meeting/46789 "2026-04-20T17:27:34Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![ebrahim](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ebrahim/32/13403_2.png) [@ebrahim](https://discourse.slicer.org/u/ebrahim)\
**Post date:** [April 20, 2026, 5:27pm UTC](https://discourse.slicer.org/t/2026-04-21-weekly-meeting/46789/1 "2026-04-20T17:27:35Z")

</div>

Title: 2026.04.21 Weekly Meeting

Next Tuesday, we will be having our next weekly hangout at **10:00 AM ET until 11:00 AM ET.**

Anyone is welcome to join at this link: [https://bit.ly/slicer-googlemeet-hosted-by-kitware](https://bit.ly/slicer-googlemeet-hosted-by-kitware)

* * *

> **Weekly Meeting**
>
> **Starts:** April 21, 2026, 10:00am (America/New\_York)\
> **Link:** <https://bit.ly/slicer-googlemeet-hosted-by-kitware>

**Agenda:**

Please post to this thread to put a topic on the agenda! We will try to prioritize agenda items during the meeting.

* * *

Thanks  
Sam and Ebrahim

---

<div class="post-metadata">

**Author:** ![ebrahim](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ebrahim/32/13403_2.png) [@ebrahim](https://discourse.slicer.org/u/ebrahim)\
**Post date:** [April 20, 2026, 5:29pm UTC](https://discourse.slicer.org/t/2026-04-21-weekly-meeting/46789/2 "2026-04-20T17:29:57Z")

</div>

> 🤖 This post was written with AI assistance.

Already on the agenda is the discussion started at [2026.04.14 Weekly Meeting - #3 by pieper](https://discourse.slicer.org/t/2026-04-14-weekly-meeting/46731/3)

## Extension review and publishing

[ExtensionsIndex#2341](https://github.com/Slicer/ExtensionsIndex/issues/2341) by Steve: make it easy to install extension PRs, since unfunded review creates a backlog that hurts contributors and users.

### To discuss:

- Tier-based filtering of extensions (status update from Kyle).
- Move packaging off the factory onto GitHub Actions:
  - Andras’s prototype: [Slicer#9118](https://github.com/Slicer/Slicer/pull/9118).
  - Example use: [SlicerMONAIAuto3DSeg#105](https://github.com/lassoan/SlicerMONAIAuto3DSeg/pull/105).

- Proposals as to how much review we want:
  - _Andras:_ allow publish-without-review; surface quality via ratings/likes; promote highly-rated ones into higher tiers.
  - _Steve:_ treat it like publishing a repo/website; minimal formal process; users recommend to users.
  - _Murat:_ keep peer review but make high-demand extensions pay an annual review/support fee; use an AI agent to screen new submissions for malicious code and ship others as “use at your own risk.”

- Sandboxing to protect users from untrusted extension code (and untrusted AI agents). Options raised: containers, cloud execution, and eventually browser-based (SlicerTrame, VTK wasm, pyodide).
- A feature in Slicer to install/build extension PRs directly. Pure-Python extensions are low-hanging fruit; also a “check out and build” button when running a locally built Slicer.

---

<div class="post-metadata">

**Author:** ![ebrahim](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ebrahim/32/13403_2.png) [@ebrahim](https://discourse.slicer.org/u/ebrahim)\
**Post date:** [April 20, 2026, 5:31pm UTC](https://discourse.slicer.org/t/2026-04-21-weekly-meeting/46789/3 "2026-04-20T17:31:28Z")

</div>

Also adding for myself: [Slicer#9010](https://github.com/Slicer/Slicer/pull/9010) is ready for review

---

<div class="post-metadata">

**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [April 20, 2026, 6:09pm UTC](https://discourse.slicer.org/t/2026-04-21-weekly-meeting/46789/4 "2026-04-20T18:09:57Z")

</div>

I also want to give some more quick demos of the new rendering mode I’ve been playing with.

---

<div class="post-metadata">

**Author:** ![ebrahim](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ebrahim/32/13403_2.png) [@ebrahim](https://discourse.slicer.org/u/ebrahim)\
**Post date:** [April 21, 2026, 2:22am UTC](https://discourse.slicer.org/t/2026-04-21-weekly-meeting/46789/5 "2026-04-21T02:22:52Z")

</div>

I also recently took a stab at upgrading SlicerJupyter for Slicer 5.10 and Python 3.12 and would like to see what folks think or if anyone understands if the windows-specific aspect of the issue, which I may not have addressed.

---

<div class="post-metadata">

**Author:** ![ebrahim](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ebrahim/32/13403_2.png) [@ebrahim](https://discourse.slicer.org/u/ebrahim)\
**Post date:** [April 22, 2026, 4:42am UTC](https://discourse.slicer.org/t/2026-04-21-weekly-meeting/46789/6 "2026-04-22T04:42:38Z")

</div>

Notes from the meeting:

## Extension review and publishing (Everyone)

[ExtensionsIndex#2341](https://github.com/Slicer/ExtensionsIndex/issues/2341) by Steve: make it easy to install extension PRs, since unfunded review creates a backlog that hurts contributors and users.

### To discuss:

- Tier-based filtering of extensions (status update from Kyle).
- Move packaging off the factory onto GitHub Actions:
  - Andras’s prototype: [Slicer#9118](https://github.com/Slicer/Slicer/pull/9118).
  - Example use: [SlicerMONAIAuto3DSeg#105](https://github.com/lassoan/SlicerMONAIAuto3DSeg/pull/105).

- Proposals as to how much review we want:
  - _Andras:_ allow publish-without-review; surface quality via ratings/likes; promote highly-rated ones into higher tiers.
  - _Steve:_ treat it like publishing a repo/website; minimal formal process; users recommend to users.
  - _Murat:_ keep peer review but make high-demand extensions pay an annual review/support fee; use an AI agent to screen new submissions for malicious code and ship others as “use at your own risk.”

- Sandboxing to protect users from untrusted extension code (and untrusted AI agents). Options raised: containers, cloud execution, and eventually browser-based (SlicerTrame, VTK wasm, pyodide).
- A feature in Slicer to install/build extension PRs directly. Pure-Python extensions are low-hanging fruit; also a “check out and build” button when running a locally built Slicer.

### Action for now regarding the open extn index PRs

First step: go through and tag as to whether they are awaiting response or whether maintainer response is needed.

In general just like we have a checklist for extension developers, we should also have a _maintainer’s_ checklist of things to do. It will just be a set of steps to go through, and if it passes all those steps then it goes through. (Sam looking into this.)

## slicer.packaging PR finalized (Ebrahim)

[Slicer#9010](https://github.com/Slicer/Slicer/pull/9010) ready for review.

All review comments addressed, and now we can use the name `slicer.packaging`. Consolidated commits to somehting more comprehensible.

## New rendering mode demo (Steve)

Continued demo of WebGPU rendering experiments in Slicer, with a differet approach:  
Use WebGPU for volume rendering, but then have that volume rendering get composited into the vtk renderer.

> **[GitHub - pieper/SlicerWGPU: Use wgpu, a rust-python WebGPU implementation, in...](https://github.com/pieper/SlicerWGPU)**
>
> Use wgpu, a rust-python WebGPU implementation, in 3D Slicer

![image](https://hackmd.io/_uploads/rkT1rbSaZx.png)

Some kinks to work out but one thing that this can make possible is multi-volume rendering with proper occlusion!

![image](https://hackmd.io/_uploads/HyG9rZS6-x.png)

## SlicerJupyter (Ebrahim)

> <https://github.com/Slicer/SlicerJupyter/pull/79>
>
> I tested this on linux only. It works well!
> 
> @lassoan this picks up from your …\[xeus-update-202406\](https://github.com/Slicer/SlicerJupyter/commits/xeus-update-202406/) branch from a couple of years ago, which seems to have done most of the work of upgrading. Thank you!
> 
> On linux, this got SlicerJupyter building and running in a fairly recent Slicer 5.11 with Python 3.12.
> (I am guessing it would work in the current Slicer 5.10 as well)
> 
> Addresses the Linux aspects of the issues discussed in #78.
> 
> (There's also a possible second issue to address regarding windows and vs2022 build, which @benbennett
> was working on at \[vs2022fixes\](https://github.com/benbennett/SlicerJupyter/tree/vs2022fixes) -- I don't fully understand what was happening there but it suggests to me that what I've done here probably doesn't solve all the problems that were encountered on windows)

> [@SlicerJupyter not available for latest version?](https://discourse.slicer.org/t/slicerjupyter-not-available-for-latest-version/41791):
>
> Hello, I just noticed that SlicerJupyter was not available as an extension for both the latest stable version and the latest unstable version. What are the plans moving forward? Will SlicerJupyter work? SlicerJupyter is mission critical for my work. Thanks, Juergen