[BUG]

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

In Auto Mode, every tool call that requires the Auto Mode safety classifier (Write, Edit, and MCP tools requiring approval such as preview_start) fails with:

"claude-sonnet-5[1m] is temporarily unavailable, so auto mode cannot determine the safety of <tool> right now. Wait briefly and then try this action again..."

This has been happening continuously for 2 days across at least 3 separate sessions, including after a full system reboot and multiple Claude Code restarts. Read-only operations (Read, Grep, Glob, non-mutating Bash) are unaffected — only classifier-gated actions fail.

I initially suspected a local permission/config issue and set "permissions.defaultMode": "acceptEdits" in ~/.claude/settings.json, but this had no effect — Auto Mode still fails identically, indicating the Auto Mode classifier gate is independent of standard local permission-mode settings.

What Should Happen?

Write, Edit, and MCP tools should be evaluated by the Auto Mode safety classifier and either approved or denied based on actual safety judgment, not fail categorically due to the classifier backend being unavailable.

Error Messages/Logs

claude-sonnet-5[1m] is temporarily unavailable, so auto mode cannot determine the safety of Write right now. Wait briefly and then try this action again. If it keeps failing, continue with other tasks that don't require this action and come back to it later. Note: reading files, searching code, and other read-only operations do not require the classifier and can still be used.

Same error reproduced for Edit and mcp__Claude_Browser__preview_start, with only the tool name changing.

Steps to Reproduce

1. Start Claude Code in Auto Mode.
2. Run Bash: echo test → succeeds (read-only path, no classifier needed).
3. Use Write to create a new file (e.g. /tmp/test.txt with content "test") → fails with the classifier-unavailable error above.
4. Use Edit to modify an existing file → fails with the same error.
5. Use an MCP tool requiring approval (e.g. browser preview_start) → fails with the same error.
6. Reproduced identically across 3 separate sessions over 2 days, and on both Sonnet 5 and Opus 5.
7. As a workaround test: set "permissions.defaultMode": "acceptEdits" in ~/.claude/settings.json (global) and restart — Auto Mode still fails identically, ruling out local permission config as the cause.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

Unknown

Claude Code Version

2.1.218 (Claude Code)

Platform

Other

Operating System

Windows

Terminal/Shell

Non-interactive/CI environment

Additional Information

Debug log excerpt (~/.claude/debug/*.txt) showing the permission check being denied around the classifier failure:

"SDK permission prompt deny+interrupt: tool=Write message=User rejected writing to file: \tmp\classifier_test2.txt"
"Write tool permission denied"

Despite the "User rejected" wording, no interactive prompt was answered by a human at that point — this appears to be the SDK's internal label for an auto-deny fallback when the classifier call fails, not an actual user rejection.
Running via the Claude desktop app (not a traditional terminal) — debug log shows this session is backed by the Agent SDK ("Fast mode is not available in the Agent SDK" appears repeatedly). This may be relevant to why Auto Mode's approval flow doesn't reach an interactive human confirmation.