Claude Code system prompt diff: stricter email privacy, safer deletes, clearer game rules

rchardkovacs · x · 2026-11-04

rchardkovacs, who diffs Claude Code's system prompts daily across Opus, Sonnet, Haiku and Fable, spotted a new update:

Stricter email privacy: Claude is now told that a site's request to put a contact email in the User-Agent isn't a good enough reason to expose yours — use a generic client name or ask the user first.
Safer deletes: calling delete without specifying which onboarding guide no longer deletes anything; instead it returns a list of your guides.
Clearer game rule: making a game in an existing genre or with similar mechanics is fine; recreating a specific existing game remains off limits.
Artifact listings now paginate, so long lists no longer get cut off.

The author reads these small changes as Anthropic tightening two areas: personal data protection and irreversible actions.

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