DesignSync fails with design-system authorization error on 2.1.247 in desktop app (worked on 2.1.237)

DesignSync broken in desktop app on 2.1.247 (worked on 2.1.237)

Summary

DesignSync fails with a design-system authorization error on Claude Code
2.1.247. It worked on 2.1.229 and 2.1.237 with no setup. The error
tells the user to run /design-login, which is not available in the desktop
app — so there is no in-product path to recover.

Impact

Design-system access is unusable from the Claude Code desktop app. The
suggested remedy is a CLI-only command, leaving desktop users with no
supported route.

Error

DesignSync needs design-system authorization, and /design-login cannot run in this non-interactive session. Ask the user to run /design-login once from an interactive Claude Code session on this machine...

Reproduces on every method, including list_projects, which takes no
projectId — so it is not project- or path-specific.

Evidence (from local transcripts, ~/.claude/projects//.jsonl)

| cwd | version | DesignSync calls | auth errors |
|--------------------|---------|------------------|-------------|
| ~/develop/gwh | 2.1.229 | 4 | 0 |
| ~/develop/gwh | 2.1.237 | 6 | 0 |
| ~/develop/repeteva | 2.1.247 | 11 | 22 |

100% success before 2.1.247, 100% failure after.

Key facts ruling out user error

• /design-login has never been invoked on this machine (0 occurrences

across all transcripts). Design access previously rode on the ordinary
claude.ai login. So this is not a lapsed grant the user once created.

• The user is signed in to both the Claude Code desktop app and Claude Design

on the web, same account.

• Not path-related: no design-scoped state exists per project in

~/.claude.json (the old and new project entries have identical key sets,
neither containing design keys), and list_projects takes no path.

Confound, stated honestly

The working directory was renamed gwh -> repeteva at roughly the same time as
the upgrade, so no sample exists for gwh@2.1.247 or repeteva@2.1.237. The
rename is nonetheless ruled out by mechanism: there is no path-keyed design
credential, and the no-argument list_projects fails identically.

Suspected cause

2.1.247 appears to have added an authorization gate for design-system access
that (a) requires consent that was previously implicit, and (b) detects the
desktop app as a "non-interactive session", so it refuses to prompt and
recommends a command the desktop app cannot run.

Expected

DesignSync keeps working off the existing claude.ai login, or the consent
prompt is presented in-app where the desktop user can act on it.

Environment

• Claude Code desktop app, version 2.1.247 (broken); 2.1.229 / 2.1.237 (working)
• macOS (Darwin 25.6.0)
• Observed 2026-08-30