Contract history
Contract Changelog
Every contract change, organized by design dimension. Track what was added, modified, adopted, and deprecated across versions — from the initial 6-check contract through the current v0.4.0 40-check engine.
Pattern from Artificial Analysis: changelog organized by modality (dimension), not by version. Each entry shows the version, date, what changed, which checks were affected, and the rationale.
Four heuristic checks: button verb phrases (no "Click Here"), no trailing periods on interactive elements, descriptive link text (WCAG 2.4.4), no ALL CAPS in body copy. Grounded in NN/g, Microsoft Fluent, IBM Carbon, and WCAG.
Copy is design — "Click Here" is an accessibility failure and a usability smell. 8% weight. New in v0.4.0.
Source: NN/g, Microsoft Fluent, IBM Carbon, WCAG 2.4.4
Engine expanded from 36 to 40 checks. Copywriting category added (4 checks). Accessibility floor enforced: if accessibility scores below 60%, overall grade capped at C. Twelve anti-slop rules now subtract up to 20 points. Seven originality signals add up to 8 points.
The engine must evolve with the contract. Each version bump adds precision — the anti-slop rules catch generic AI-generated patterns that pass individual checks but fail as a composition.
Source: Designesy engine v1.0, contract v0.4.0
New check: validates DESIGN.md spec file using Google's @google/design.md CLI linter. Integrates the spec layer beneath designesy's own 40-check contract verification.
DESIGN.md is the AI-agent-facing spec file. Without it, AI coding tools build around your system, not from it. The check validates its presence and structure.
Source: Google @google/design.md CLI linter
Public commitment: Designesy does not accept payment for scores, methodology changes, or leaderboard placement. API responses now include compliance_index_version field (currently "1.0") for machine-consumable CI pipeline integration.
The trust asset must be structurally non-monetizable. Pattern from Artificial Analysis (independence firewall) and Arena (structural neutrality). The compliance_index_version field makes scores machine-consumable for CI pipelines.
Source: Artificial Analysis independence firewall, Arena structural neutrality
Lab Four acoustic mapping rules promoted to contract: interaction sound synthesis via Web Audio API, acoustic tokens for press/hover/settle sounds, sound-toggle aria-pressed, reduced-motion tiering for acoustic events.
Acoustics is the frontier — most design systems have no acoustic layer at all. The contract defines acoustic tokens the same way it defines motion tokens: named, typed, and tiered for reduced-motion.
Source: Lab Four — Acoustic mapping, Cuelume v0.1.0 engine
Lab Three typography rules promoted to contract: font-smoothing, rem-based sizes, line-height, text-wrap (balance/pretty), tabular-nums, selection styling, font-synthesis, underline-position, skip-ink. 12 checks — the largest category.
Cadence is typography rendering discipline — the difference between type that looks crisp and type that looks fuzzy. 18% weight — the highest-weighted category. Most sites fail here because font-synthesis and text-wrap are rarely declared.
Source: Lab Three — Cadence typography experiments, NY Times editorial reference
Lab Two interface-feel rules promoted to contract: stagger enter animation-delays, soften exit transforms with ease-out, concentric border-radius sets. Named after the German word for precise, musical timing.
Takt is the musicality of interaction — the timing and scaling that makes a press feel intentional. Press scales above the 0.95 floor: 0.96 cells, 0.985 cards, 0.995 surfaces.
Source: Lab Two — Takt interface-feel experiments
Lab One interaction rules promoted to contract: hover lifts with @media (hover: hover) guards, press settle scales, keyboard-path documentation, sound-toggle aria-pressed.
Poise is interaction poise — the difference between a site that feels considered and one that feels janky. Hover guards prevent touch-device flash; press scales provide tactile feedback.
Source: Lab One — Poise interaction experiments
Two scored checks for token presence: --paper foundation variable at :root, and token layer depth (primitive → semantic → component).
Token architecture is the substrate — without a root surface variable and layered tokens, every other dimension is ad-hoc. 9% weight.
Source: Designesy design system contract v0.1.0
Four checks: no transition:all, will-change restricted to transform/opacity, prefers-reduced-motion block present, duration tokens declared.
Motion hygiene is the most violated dimension in the cohort. transition:all causes layout thrashing; missing reduced-motion is an accessibility failure.
Source: Designesy design system contract v0.1.0
Six checks: contrast ratios, touch targets (44px), heading hierarchy, input font floor (16px), button-text contrast, forced-colors readiness.
Accessibility carries the a11y floor: if this category scores below 60%, the overall grade is capped at C. 15% weight — the highest single category.
Source: WCAG 2.2 AA, APCA contrast model
Two checks: semantic HTML landmarks (h1, title, meta description, main/header/nav) and AI-disclosure readiness per EU AI Act Art 50.
Document identity is the machine-readable surface — without landmarks and meta, the page is opaque to both screen readers and AI agents.
Source: EU AI Act Article 50, HTML landmark spec
One check: UTS #39 confusable detection in token names and CSS identifiers. Prevents Cyrillic/Greek homoglyph shadowing attacks.
Designesy is the only design verification engine that checks this surface. Homoglyph attacks in CSS identifiers can spoof brand colors and redirect trust.
Source: Unicode Technical Standard #39
The scoring engine itself: CSS extraction, :root custom property parsing, 40 checks across 14 weighted categories, A-F grade bands.
The engine is the moat — deterministic, open, and reproducible. No LLM, no human judgment, no survey. The same engine scores every site identically.
Source: Designesy engine v1.0