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Garry Tan
6cedecd585
Cuts Haiku classifier false-positive rate from 44.1% → 22.9% on BrowseSafe-Bench smoke. Detection trades from 67.3% → 56.2%; the lost TPs are all cases Haiku correctly labeled verdict=warn (phishing targeting users, not agent hijack) — they still surface in the WARN banner meta but no longer kill the session. Key changes: - combineVerdict: label-first voting for transcript_classifier. Only meta.verdict==='block' block-votes; verdict==='warn' is a soft signal. Missing meta.verdict never block-votes (backward-compat). - Hallucination guard: verdict='block' at confidence < LOG_ONLY (0.40) drops to warn-vote — prevents malformed low-conf blocks from going authoritative. - New THRESHOLDS.SOLO_CONTENT_BLOCK = 0.92 decoupled from BLOCK (0.85). Label-less content classifiers (testsavant, deberta) need a higher solo-BLOCK bar because they can't distinguish injection from phishing-targeting-user. Transcript keeps label-gated solo path (verdict=block AND conf >= BLOCK). - THRESHOLDS.WARN bumped 0.60 → 0.75 — borderline fires drop out of the 2-of-N ensemble pool. - Haiku model pinned (claude-haiku-4-5-20251001). `claude -p` spawns from os.tmpdir() so project CLAUDE.md doesn't poison the classifier context (measured 44k cache_creation tokens per call before the fix, and Haiku refusing to classify because it read "security system" from CLAUDE.md and went meta). - Haiku timeout 15s → 45s. Measured real latency is 17-33s end-to-end (Claude Code session startup + Haiku); v1's 15s caused 100% timeout when re-measured — v1's ensemble was effectively L4-only in prod. - Haiku prompt rewritten: explicit block/warn/safe criteria, 8 few-shot exemplars (instruction-override → block; social engineering → warn; discussion-of-injection → safe). Test updates: - 5 existing combineVerdict tests adapted for label-first semantics (transcript signals now need meta.verdict to block-vote). - 6 new tests: warn-soft-signal, three-way-block-with-warn-transcript, hallucination-guard-below-floor, above-floor-label-first, backward-compat-missing-meta. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>