Desktop app: a cloud session opened from a claude.ai/code/session_… link inside an Artifact never finishes loading
<img width="1607" height="1182" alt="Image" src="https://github.com/user-attachments/assets/e6836b37-8e3f-4c21-9515-d5f5bf45dc9c" />
What happens
In the Claude desktop app (Windows 11), clicking a link to a cloud Claude Code session from inside a published Artifact opens the session in a new Code window, but the window never finishes loading. The session title and the Runs panel header appear, so the app resolved the session. The conversation stays on the grey skeleton placeholders and the Runs panel spins forever. Waiting doesn't help.
Steps to reproduce
- Start a cloud session from a Routine (any routine run).
- Publish an Artifact page with a plain link to that session's URL, as the Routines API returns it:
<a href="https://claude.ai/code/session_<id>" target="_blank" rel="noopener">Open session</a>
- Open the Artifact in the desktop app and click the link.
Expected
The session loads, as it does when opened from Routines → the run in the same app.
Actual
The new Code window stays on the loading skeleton (screenshot attached; personal details redacted).
What still works
- The same link clicked from the same Artifact in Chrome opens the session in a new tab, and it loads completely.
- Opening the session from Routines inside the desktop app loads normally.
So the URL is valid. The failure is only in the desktop app's handling of that link when it comes from an Artifact.
Regression
This worked until recently, with the same links on the same Artifact. It started failing on or before 2026-10-14.
Environment
- Claude desktop app, Windows 11 Pro 10.0.26100
- Cloud session started by a Routine; model Opus 5.5