# Unable to connect to localhost Nucleus from Python standalone application

**URL:** <https://forums.developer.nvidia.com/t/unable-to-connect-to-localhost-nucleus-from-python-standalone-application/283068>\
**Category:** Isaac Sim\
**Tags:** nucleus\
**Created:** [February 16, 2024, 4:12pm UTC](https://forums.developer.nvidia.com/t/unable-to-connect-to-localhost-nucleus-from-python-standalone-application/283068 "2024-02-16T16:12:18Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![koehne1](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@koehne1](https://forums.developer.nvidia.com/u/koehne1)\
**Post date:** [February 16, 2024, 4:12pm UTC](https://forums.developer.nvidia.com/t/unable-to-connect-to-localhost-nucleus-from-python-standalone-application/283068/1 "2024-02-16T16:12:18Z")

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I’m trying to connect to my localhost Nucleus server installed on an Ubuntu 22.04 Workstation I’m working from. The Nucleus Server is perfectly reachable from the web browser using [http://localhost:34080](http://localhost:34080). Whenever I try to access assets from Nuclues in my Standalone Python app, the log is telling me that Nucleus is not accessible.

[Info] [omni.isaac.core.utils.nucleus] Check /persistent/isaac/asset\_root/default setting  
[Info] [omni.isaac.core.utils.nucleus] Checking path: omniverse://localhost/NVIDIA/Assets/Isaac/2023.1.1/Isaac  
[Info] [omni.isaac.core.utils.nucleus] Failure: omniverse://localhost/NVIDIA/Assets/Isaac/2023.1.1/Isaac not accessible

is there anything I am missing here? I even passed my Nucleus admin credentials with:

$export OMNI\_USER=  
$ export OMNI\_PASS=

Any help is really appreciated!

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**Author:** ![VickNV](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/vicknv/32/14043_2.png) [@VickNV](https://forums.developer.nvidia.com/u/VickNV)\
**Post date:** [April 19, 2026, 9:59pm UTC](https://forums.developer.nvidia.com/t/unable-to-connect-to-localhost-nucleus-from-python-standalone-application/283068/3 "2026-04-19T21:59:46Z")

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Hi @koehne1,

A local Nucleus server is no longer required for Isaac Sim. Starting with **Isaac Sim 5.0+** , assets are served directly from NVIDIA’s CDN and the `get_assets_root_path()` function resolves to an S3 URL by default — no Nucleus setup needed.

If you’re still working with a local Nucleus server on a newer version, the connection issue was likely due to the `omni.client` library requiring Nucleus authentication via the Omniverse Launcher login rather than environment variables.

We recommend upgrading to [Isaac Sim 6.0.0](https://docs.isaacsim.omniverse.nvidia.com/6.0.0/installation/install_workstation.html) where asset access is simpler and doesn’t require Nucleus.

Closing due to age.

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<div class="post-metadata">

**Author:** ![VickNV](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/vicknv/32/14043_2.png) [@VickNV](https://forums.developer.nvidia.com/u/VickNV)\
**Post date:** [April 19, 2026, 9:59pm UTC](https://forums.developer.nvidia.com/t/unable-to-connect-to-localhost-nucleus-from-python-standalone-application/283068/4 "2026-04-19T21:59:49Z")

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