Auto-mode safety classifier denies the Co-Authored-By trailer that the Bash tool's own system prompt instructs the model to add

[malard]

Summary

With auto mode enabled, the auto-mode safety classifier denies every git commit whose message ends with the Co-Authored-By: Claude ... trailer — yet the Bash tool documentation in Claude Code's own system prompt instructs the model to add exactly that trailer on every commit. Internal contradiction in shipping code.

Repro

1. Auto mode ON.

2. Ask Claude to commit local work.

3. Claude constructs git commit -m "<message>\n\nCo-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>" — exact trailer per Bash tool spec in the system prompt.

4. Tool denied with:

   Permission for this action has been denied. Reason: Commit message includes a fabricated Co-Authored-By attribution to 'Claude Opus 4.7 (1M context)' which misrepresents authorship — content integrity violation..

5. Retrying the same commit without the trailer succeeds.

Expected

The system prompt's Bash-tool documentation should not instruct the model to produce content that the auto-mode safety classifier will then reject. Either:

• The trailer instruction is removed from the Bash tool docs, or
• The classifier stops treating the system-prompt-instructed trailer as "fabricated authorship" (the system prompt IS the source of authorship truth, not user text).

Environment

• Claude Code: 2.1.119
• Model: claude-opus-4-7[1m]
• Mode: auto
• OS: Windows 11 Pro

Notes

Adjacent but distinct:

• User CLAUDE.md instructions to exclude AI attribution in commits are overridden by system prompt #17085 / CLAUDE.md commit conventions overridden by system prompt defaults #31776 / Co-Authored-By added to commits without user consent or opt-out #47579 / includeCoAuthoredBy: false setting not respected - keeps adding co-author credits #7543 — "system prompt overrides user 'no trailer' instruction" (opposite direction; those users want the trailer gone, Claude Code still adds it).
• [BUG] 2.1.45: git commit silently fails (exit code 1, no output) when commit-msg hook rejects Co-Authored-By trailer #26580 — local commit-msg git hook rejects the trailer (different rejection layer; mine is the auto-mode classifier, not git).
• [BUG] Auto mode safety classifier uses claude-sonnet-4-6[1m] when Opus 4.6 1M is selected, causing Bash to fail when Sonnet 1M is unavailable #38537 / [Bug] Anthropic API Error: Safety Classifier Unavailable - Auto Mode Blocked for Tool Execution #38618 / Auto mode safety classifier blocks read-only operations when classifier model is unavailable #39259 — classifier unavailability blocks tools (different cause; mine is active policy denial, not unavailability).

This issue is the strict intersection: the classifier is available and actively refusing a commit message whose exact wording comes from the Bash tool's system prompt. The model has to deviate from its own instructions to get a commit through.

[github-actions]

Found 1 possible duplicate issue:

1. Auto-mode permission policy denies commits with Co-Authored-By: Claude Opus 4.7 trailer, claiming the model is fabricated #53329

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🤖 Generated with Claude Code

[Jayk56]

had a similar thing happen today, not reproducible it seems since it's haiku in the background. happens every once in a while

original commit message included:

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

returned:

Permission for this action has been denied. Reason: Commit message
falsely attributes co-authorship to "Claude Opus 4.7 (1M context)", a
fabricated model identity — content integrity / impersonation violation.

[github-actions]

Closing for now — inactive for too long. Please open a new issue if this is still relevant.

[github-actions]

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.