# Designesy — /contracts/drift Canonical page: https://www.designesy.org/contracts/drift --- ## Drift Drift is the named 2026 design-system crisis: AI-generated UI drifts off-contract in four documented ways. This contract defines the checks that detect drift deterministically from compiled CSS, not from prose advice. Version 0.1.0 · provisional · [machine export](https://www.designesy.org/contracts/drift.json) ## Source authority Designesy design intelligence research 2026-08-01 Superdesign / DLS Lead / Codexical — four-mode drift taxonomy OverlayQA — ~160 visual issues per AI-generated app (Jason Arbon, 1000+ checks) Figma 2025 — 23% design-system drift in 8 weeks without formal review vs 4% with it ## The four drift modes ## Conformance Fetch the URL HTML + all linked CSS. Extract :root custom property declarations and all var() references. Compare declared tokens against referenced tokens. Measure value variance across declarations for spacing, color, radius, shadow, and timing. ## Verification 12 checks — 12 checks. PASS=1, WARN=0.5, FAIL=0. Score = (points/12) × 100. A≥90, B≥80, C≥70, D≥60, F<60. Validation: Designesy drift engine — CSS extraction + var() reference analysis. Method: Fetch HTML + linked CSS, extract :root declarations and var() calls, compute variance. Browser-only checks: None — all 12 checks are static CSS/HTML analysis, no browser needed. ## Open questions - Between-session amnesia (mode 3) requires historical snapshots — the current engine detects within-page drift only - Silent breaking changes (mode 4) require version tracking — the current engine detects the current state only - Cross-page drift (mode 2) requires crawling multiple pages — the current engine analyzes the single fetched URL - The engine may flag third-party CSS (analytics, embeds) as fabricated tokens — a suppression list may be needed ## Run it Score any URL for drift: