# How to upload a Custom Theme from scratch using the Gateway API?

**URL:** <https://forum.inductiveautomation.com/t/how-to-upload-a-custom-theme-from-scratch-using-the-gateway-api/116771>\
**Category:** Ignition\
**Tags:** ignition83\
**Created:** [August 12, 2026, 9:33pm UTC](https://forum.inductiveautomation.com/t/how-to-upload-a-custom-theme-from-scratch-using-the-gateway-api/116771 "2026-08-12T21:33:18Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Michael\_Lindon](https://avatars.discourse-cdn.com/v4/letter/m/3d9bf3/32.png) [@Michael\_Lindon](https://forum.inductiveautomation.com/u/Michael_Lindon)\
**Post date:** [August 12, 2026, 9:33pm UTC](https://forum.inductiveautomation.com/t/how-to-upload-a-custom-theme-from-scratch-using-the-gateway-api/116771/1 "2026-08-12T21:33:18Z")

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![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/4/f/4f82e0f09bb95793fcca776efead58ca38ab3611.png)

Trying to see if I can setup a Theme remotely using the Ignition API. I have gotten my API calls to read theme data and have used the create theme API endpoint to create the theme instance. Now, I am trying to figure out how to upload the customized CSS files. There isn't a create endpoint, so I am thinking I need to use this endpoint. Is that correct? If so, what is the expected payload? When I send the payload as Text/CSS I am getting empty responses from the Ignition Server. Any help is appreciated!

Note, I am using Ignition 8.3.8.

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [August 13, 2026, 12:00am UTC](https://forum.inductiveautomation.com/t/how-to-upload-a-custom-theme-from-scratch-using-the-gateway-api/116771/2 "2026-08-13T00:00:40Z")

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Related topic:

> [@Using system.config to create themes across gateways](https://forum.inductiveautomation.com/t/using-system-config-to-create-themes-across-gateways/116738):
>
> I am trying out the new system.config functions to send a custom theme to remote gateways. Here is my project library script and my corresponding message script. def sendHpHmiTheme(gateways = None): if not gateways: gateways = getOnlineGateways() if not gateways: # No gateways are online return # Get resource definition and package it into payload res = system.config.getResource(moduleId="com.inductiveautomation.perspective", typeId="themes", name="hp-hmi") configData = { 'nam…