Lilith Metaverse · Reference & analysis

V3 Web First-Load Budget

shell reaching interactive render of the root route (/) on a cold HTTP cache and cold service-worker state: no prior oshun-v3-tier2-cache-v1 entries, no warm DNS/TLS session.

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Canonical source: libs/oshun/analytics/src/v3-web-first-load-budget.ts

Manifest version: v3-web-first-load-budget.v1

The GA web first-load gate validates the root V3 web route on the required desktop and mobile profiles. The p95 budgets are normative; the committed "observed" figures are hand-authored projections — the corresponding V3/V3_TODOS.md §66 task is [~] and V3/VERIFICATION_AUDIT_2026-05-31.md confirmed no real-device run exists. Real-device measurement is pending.

Profile Device Network p95 budget Projected p95 (measurement pending)
m1-mac-broadband M1 Mac Broadband <= 8,000 ms 6,940 ms
pixel-7-cellular Pixel 7 Cellular <= 12,000 ms 10,860 ms

Methodology#

  • Metric. First load is wall-clock time from navigation start to the V3 web shell reaching interactive render of the root route (/) on a cold HTTP cache and cold service-worker state: no prior oshun-v3-tier2-cache-v1 entries, no warm DNS/TLS session. Each sample is one full cold navigation in a fresh browser context.
  • Percentile definition. p95 is computed per profile over the full sample set using nearest-rank on the sorted first-load times. A profile passes only if p95 <= its budget; the per-sample max and sample count are retained in the evidence so percentile consistency can be re-checked.
  • Sample count. >= 30 samples per profile is the manifest floor (minSampleCount); the committed evidence set declares 60 samples per profile. Runs below the floor are rejected.
  • Device / network profiles.
    • m1-mac-broadband: Apple M1 macOS, Chromium-engine browser, unthrottled broadband (>= 100 Mbps, < 20 ms RTT to the nearest edge).
    • pixel-7-cellular: Pixel 7 Android, Chrome, cellular profile throttled to sustained 4G (~9 Mbps down / 170 ms RTT), matching the §66 budget's "Pixel 7 cellular" wording.
  • Measurement procedure. For each profile: (1) deploy the production build of the V3 web app (apps/v3/lilith-web); (2) clear browser storage, caches, and service workers; (3) navigate to the root route and record navigation-start → interactive-render time via the Playwright trace (apps/v3/lilith-web-e2e first-load spec, with source parity coverage in the Tier-2 fallback shell); (4) repeat for the full sample count, discarding no samples; (5) write per-sample timings, sample count, p95, and measuredAtIso into the evidence consumed by the manifest. This mirrors the deterministic-harness structure of V3/COLD_JOIN_VALIDATION.md, but unlike cold join it requires the real devices and network shaping above — which is why it is measurement-pending rather than locally verified.

The evidence path is apps/v3/lilith-web/e2e/lilith-web-shell.spec.ts, with source parity coverage in the Tier-2 fallback shell. The verifier (pnpm verify:v3 web-first-load-budget) fails closed when a required profile is missing, p95 exceeds budget, sample count is below the profile floor, CI is not green, or percentile evidence is malformed. When the real-device runs land, replace the projected column with measured values and drop the measurement-pending caveat.