Agent builder: Skill attached to Shell disappears after reload/tab close

API Bugs
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1

I am using Agent Builder on platform.openai.com.

I can upload/select a Skill in the Agent Builder UI and it appears attached to the Agent node / Hosted Shell tool, but after reloading the page or closing and reopening the tab, the Skill is gone.

I tested this with:

  1. a newly created agent/workflow;
  2. a minimal valid skill package containing only one top-level folder and SKILL.md;
  3. a simplified skill package following the documented structure;
  4. a package where the folder name and the skill name match;
  5. publishing/updating the workflow before closing/reloading.

The issue persists, so it does not appear to be caused by the skill content.

Also, when I click Code → Agents SDK, code generation fails with: “Failed to generate code. Unknown tool type: shell.”

This seems inconsistent because the Platform documentation describes shell as a supported Responses API tool and documents skills as mountable through tools [].environment.skills in hosted shell environments.

Expected behaviour: Agent Builder should either generate valid code for Hosted Shell or clearly indicate that Hosted Shell is not supported by the code exporter.

Actual behaviour: the Builder allows adding Hosted Shell, but the code exporter fails with “Unknown tool type: shell.”

Could you confirm whether Skills are currently fully supported as persistent attachments in Agent Builder, or whether the UI is exposing an incomplete/beta integration?

Expected behavior:
The Skill remains attached to the Agent node / Hosted Shell tool after reload or tab close.

Actual behavior:
The Skill appears temporarily in the UI but disappears after reload or after closing and reopening the tab.

2

This is happening to me also. Hosted Shell is suddenly gone when I upload the skill. I think this is a bug.

To make things worse, I don’t think the SKILLS appear to be working at all.

If you ask the agent “what are your skills” (just use you are a helpful assistant as agent instructions). The agent is unable to find any skill.

I tried two methods.

(1) Uploading the skill via agent builder > tools > shell > upload skills

(2) In platform.openai > storage > skills > upload

both are not working