ab-v3 / ab-v4 showed Phase 1A (cookbook strip on obvious difficulty)
shaved ~4.4k tokens off T-obvious. Phase 2 adds a per-category gate
that strips cookbook recipes whose domain doesn't match the prompt's
category — mobile briefs don't see dashboard recipes, dashboard
briefs don't see mobile / landing recipes, etc.
Mechanism: HTML comment block markers in elements.md
(`<!-- @domain:dashboard --> ... <!-- /@domain -->`) plus a
stripNonMatchingDomains() pass in buildSystemPrompt that drops blocks
whose tag list doesn't include the active category. Untagged content
is "general" and stays in every variant — the safe default.
Tagged 7 single-domain cookbook recipes:
- dashboard: Team / members list, Audit / activity feed, Faceted
search filter sidebar, Dashboard KPI strip
- landing: Pricing section
- mobile: Onboarding "How it works", Support chat thread
Cross-domain recipes (Login, Signup, Settings page, OTP, Empty
inbox) stay untagged so they load for every category. Decision tree
+ PREFER list also untagged today; the per-tool annotations there
would be a much larger judgment pass for marginal additional savings.
Token measurements (chars / 4 estimate):
full mobile dashboard landing
- T + composite 19.0k 17.9k 18.4k 17.7k
(-1.1k) (-0.6k) (-1.3k)
- T + obvious 14.6k 13.5k 14.0k 13.3k
(-1.1k) (-0.6k) (-1.3k)
Modest absolute savings — Phase 2 only filters cookbook RECIPES (in
elements.md), and most cookbook content is in elements-cookbook.md
which Phase 1A already strips on obvious. To hit the 6-8k T target
we still need decision-tree compression or PREFER-list trim, but
both are lossier than this gate. Phase 3 candidates noted in the
ab-v4 results doc.
real-model.ts plumbs call.prompt.category through to buildSystemPrompt.
3766 vitest pass (+6 category filter tests including a 500-char
floor regression guard that the filter actually shaves bytes).
c835976479