Bug: Images sent via App Engine are treated as generic files instead of images

[Pratheek555]

Description:

When sending images through apps built using the Rocket.Chat App Engine, the images are delivered to the chat as generic file attachments instead of being rendered as inline images (with preview / thumbnail support).

Steps to reproduce:

1. Create a Rocket.Chat app using the App Engine
2. From the app, send a message containing an image attachment using the App Engine APIs. (in my case this a customized slash command to the user)
3. Open the message in a channel

Expected behavior:

2026-02-08.23-10-57.mp4

Actual behavior:

[Pratheek555]

If anyone is interested to work on this issue would love to collaborate. I have made the changes locally which is shown in the EXPECTED BEHAVIOR of the issue, but I feel there could be a better implementation.

[deepak0x]

hey @Pratheek555
i would like to work on this issue

[Shreyas2004wagh]

Hey @Pratheek555 , I would like to work on this

[Pratheek555]

Hey guys,

I am fellow contributor as you are and as far as I know we don't get issues assigned. So feel free to solve the issue and if required collaborate on it.