Open with… > napari not working correctly on macOS

[jni]

I installed the napari 0.6.6 bundle for macOS to be able to open my files in napari 🤩, but unfortunately it doesn't work: napari gets launched but with an empty viewer, that I then need to drag and drop the file to.

Can others reproduce on other OSs? @psobolewskiPhD @brisvag @TimMonko

napari info:

napari: 0.6.6 (from conda)
Platform: macOS-15.6-arm64-arm-64bit
System: MacOS 15.6
Python: 3.11.14 | packaged by conda-forge | (main, Oct 13 2025, 14:29:50) [Clang 19.1.7 ]
Qt: 6.9.3
PySide6: 6.9.3
NumPy: 2.3.3
SciPy: 1.16.2
Dask: 2025.10.0
VisPy: 0.15.2
magicgui: 0.10.1
superqt: 0.7.6
in-n-out: 0.2.1
app-model: 0.4.0
psygnal: 0.14.2
npe2: 0.7.9
pydantic: 2.12.2

OpenGL:
- PyOpenGL: 3.1.10
- GL version: 2.1 Metal - 89.4
- MAX_TEXTURE_SIZE: 16384
- GL_MAX_3D_TEXTURE_SIZE: 2048

Screens:
- screen 1: resolution 3200x1800, scale 2.0
- screen 2: resolution 1800x1169, scale 2.0

Optional:
- numba: 0.62.1
- triangle not installed
- napari-plugin-manager: 0.1.7
- bermuda: 0.1.6
- PartSegCore: 0.15.14

Experimental Settings:
- Async: False
- Autoswap buffers: False
- Triangulation backend: Fastest available

Settings path:
- /Users/jni/Library/Application Support/napari/napari-0.6.6_81e0b94dcde979ec1c843c3cc54ba708f1d7b6ca/settings.yaml

Launch command:
- /Library/napari-0.6.6/envs/napari-0.6.6/lib/python3.11/site-packages/napari/__main__.py

Plugins:
- napari-svg: 0.2.1 (2 contributions)
- napari-console: 0.1.4 (0 contributions)
- napari: 0.6.6 (88 contributions)

[TimMonko]

I am unable to reproduce on Windows -- things are working for me.

napari: 0.6.6 (from conda)
Platform: Windows-10-10.0.26100-SP0
Python: 3.11.14 | packaged by conda-forge | (main, Oct 13 2025, 14:00:26) [MSC v.1944 64 bit (AMD64)]
Qt: 6.9.3
PySide6: 6.9.3
NumPy: 2.3.3
SciPy: 1.16.2
Dask: 2025.10.0
VisPy: 0.15.2
magicgui: 0.10.1
superqt: 0.7.6
in-n-out: 0.2.1
app-model: 0.4.0
psygnal: 0.14.2
npe2: 0.7.9
pydantic: 2.12.2

OpenGL:
- PyOpenGL: 3.1.10
- GL version: 4.6.0 NVIDIA 581.08
- MAX_TEXTURE_SIZE: 32768
- GL_MAX_3D_TEXTURE_SIZE: 16384

Screens:
- screen 1: resolution 2560x1440, scale 1.5
- screen 2: resolution 1440x2560, scale 1.0

Optional:
- numba: 0.62.1
- triangle not installed
- napari-plugin-manager: 0.1.7
- bermuda: 0.1.6
- PartSegCore: 0.15.14

Experimental Settings:
- Async: False
- Autoswap buffers: False
- Triangulation backend: Fastest available

Settings path:
- C:\Users\timmo\AppData\Local\napari\napari-0.6.6_a0e4edcdd9b3d273b02f5e96c04af9b38aef73cd\settings.yaml

Launch command:
- C:\Users\timmo\AppData\Local\napari-0.6.6\envs\napari-0.6.6\Lib\site-packages\napari\__main__.py C:\Users\timmo\Downloads\01\01\t001.tif

Plugins:
- napari: 0.6.6 (88 contributions)
- napari-console: 0.1.4 (0 contributions)
- napari-svg: 0.2.1 (2 contributions)

[jni]

That's good! @psobolewskiPhD? Would be interesting to know whether it's macOS or my macOS.

[TimMonko]

Well, can you open a file that you are sure will open with base napari? I know from past testing that if you try to load in something that imageio thinks it can load, than you will get a blank napari viewer without any type of warning on what happened.

[jni]

yes: if I then drag the same file into the empty viewer I just opened, it opens perfectly fine.

[psobolewskiPhD]

Hmm, so first of all I got:

But the app is there in my Applications...
...and it does run.

Open with... and choosing napari gives me an empty viewer.
Also if I associate the file with napari and double click it, I get the same thing -- empty viewer.
I tested several different tiff, jpg, and png, all of which open just fine by drag and drop.

So it's not fully baked on macOS it seems.

[jni]

Ok, so I went back to the original PR (#284), since moved to napari/napari (#308 and napari/napari#8359) and it looks like the file name is missing from the macOS invocation:

Windows invocation uses %*:

https://github.com/napari/napari/blob/21cc57c225c041c8369a14d34c1dfdfbd896a048/resources/conda_menu_config.json#L21-L26

                    "command": [
                        "{{ PYTHON }}",
                        "-m",
                        "napari",
                        "%*"
                    ],

Linux invocation uses %F:

https://github.com/napari/napari/blob/21cc57c225c041c8369a14d34c1dfdfbd896a048/resources/conda_menu_config.json#L217-L222

                    "command": [
                        "{{ PYTHON }}",
                        "-m",
                        "napari",
                        "%F"
                    ],

macOS invocation has no file patterns:

https://github.com/napari/napari/blob/21cc57c225c041c8369a14d34c1dfdfbd896a048/resources/conda_menu_config.json#L520-L524

                    "command": [
                        "{{ MENU_ITEM_LOCATION }}/Contents/Resources/python",
                        "-m",
                        "napari"
                    ],

Since the windows and linux %exprs are different, I'm not sure what is the correct invocation for macOS. @jaimergp would you mind pointing out what it should be and whether there is a documentation page for this in constructor? I couldn't find it... 🙏

[jni]

Ah, I found this:

https://conda.github.io/menuinst/defining-shortcuts/#file-types

which says:

On macOS, use CFBundleDocumentTypes. Requires no placeholder. The opened document will be automatically passed as a regular command-line argument.

However, that does not seem to have panned out. 😅