Contract Changelog

POST /api/score takes an optional contract: your DESIGN.md or DTCG token file, pasted or linked. The answer is two numbers that are never blended. Contract fidelity reads your contract: palette, type scale, line heights, radius, spacing, contrast pairs, aliases and token use (f01 to f14). The baseline reads no contract: focus rings, reduced motion, headings, inputs, button and link copy, identity. A contract the engine cannot read answers with each problem, its path and line. The formula is published at /api/score/checks/own-contract.

A team's own design system is the contract its pages are meant to follow, and the Designesy score measures Designesy's. Fidelity answers how closely a page follows the team's own; the baseline keeps the universal checks every site is held to, without Designesy's own taste checks, slop or originality. Requests without a contract are unchanged: no legacy verdict, detail or score moves, measured on the calibration corpus and on every legacy request the gate replays.

Source: engine 1.5.0 entry in CHANGELOG.md; W3C Design Tokens Format Module 2025.10; the DESIGN.md format (alpha); WCAG 2.2 SC 1.4.3 and 2.5.8

The accessibility sweep that runs on each change to designesy.org filtered axe-core by the tag wcag2a2a, which axe does not have. Given an unknown tag, axe runs no rules and reports no violations, so from its first run on 2026-10-04 to 2026-10-13 the axe half of the gate could not fail; its heading and landmark checks still ran. The sweep now runs the five tags the accessibility contract names (wcag2a, wcag2aa, wcag21a, wcag21aa, wcag22aa) and fails any page where axe runs no rules. Re-run on 2026-10-13 on all 70 routes, light theme at 1440px: no violations at any impact level.

A sweep that runs no rules reports the same result as one that passes, so a run with no rules is now a failure. Scores of other sites are untouched: the engine does not use this sweep. The 0 violations figure on /docs/mcp comes from a separate sweep on 2026-10-11 with the five tags, 140 page scans in the light and dark themes, so it stands.

Source: designesy-org pull request 316; axe-core 4.12.1 (runOnly with an unknown tag evaluates no rules)

Two edits shipped under 0.1.0 without a version. On 2026-10-12 the adoption signal moved to the 2026 zeroheight report for the hand-synced figure (60%, where it had said 40%: 40% is the share of teams with a token pipeline), and the designMd bundle line named the open DESIGN.md format without the vendor. On 2026-10-13 token adoption moved to the 2026 report's 86% (84% is the 2025 report's figure, and the 2025 report does not date the 56% it rose from).

Every contract change is versioned and dated in this changelog. These two were not, so 0.1.1 records them. No rule, threshold or weight changed.

Source: Designesy guardrails contract v0.1.1; zeroheight Design Systems Report 2026 (report.zeroheight.com)

r05 and the readiness signal list now say "the DESIGN.md format" where they said "the @google/design.md standard" and "Google design.md standard". The readiness check reports r05 under the same new name. The package name stays where it is an install command, a code sample or a source citation.

Wording only: the DESIGN.md format is the thing a site serves, and the package is one tool that lints it. No rule, threshold or weight changed.

Source: Designesy AI readiness contract v0.1.1

The method line now says the bundle generates "a file in the open DESIGN.md format", where 0.1.1 read "the DESIGN.md file (the open DESIGN.md format)".

Wording only: the name appeared twice in one phrase. No rule, threshold or weight changed.

Source: Designesy guardrails contract v0.1.2

The g06 check now reads "DESIGN.md emitted: the open DESIGN.md format (google-labs-code/design.md)", where it read "DESIGN.md emitted: Google open spec (google-labs-code/design.md)". The guardrails report shows the new name.

Wording only: the DESIGN.md format is the thing the bundle emits, and the repository stays as its source. No rule, threshold or weight changed.

Source: Designesy guardrails contract v0.1.3

The schema description and the token-path field description name the DESIGN.md format where they said "Google design.md".

review-findings schema: description wording; schemaVersion 1.0 unchanged, no field or constraint changed.

Source: Designesy review-findings schema (/specs/review-findings.json)

One edit shipped under 0.1.0 without a version. On 2026-09-28 em dashes became colons or parentheses in source_authority, the diff dimensions, every check, the scoring note, the validation tools, relationship_to_core and open_questions. The purpose says "instead of file uploads", the scoring note says the score reflects diff completeness "rather than design quality, which is the /score surface", and token-value-changed is "the core drift indicator" where it said signal.

Every contract change is versioned and dated in this changelog. This one was not, so 0.1.1 records it. No rule, threshold or weight changed.

Source: Designesy compare contract v0.1.1; designesy-org pull request 153 (3d62df0)

One edit shipped under 0.1.0 without a version. On 2026-09-28 the Card / pillar hover obligation became "fine pointer only: gated on (hover: hover) and (pointer: fine)", with a colon where it had an em dash. This export also reads the design-system contract: its contract_version, component list, press scales and accessibility list follow that contract, and this changelog records those changes under the design-system versions.

Punctuation only. No rule, binding, threshold or weight changed.

Source: Designesy components contract v0.1.1; designesy-org pull request 153 (3d62df0)

Two edits shipped under 0.1.0 without a version. On 2026-09-28 em dashes became colons or parentheses across the drift modes, the twelve checks, the validation tools and open_questions, and silent_breaking_changes says consumers inherit the change "without notice" where it said signal. On 2026-10-12 the purpose dropped the line calling drift "the named 2026 design-system crisis" and now says AI-generated UI can drift off the tokens a site declares, and source_authority dropped two entries: the attribution of the four-mode taxonomy, and a drift-rate figure (23% in 8 weeks without formal review, 4% with it). The DRIFT_CHECK_COUNT export added on 2026-09-24 changed no served text.

Wording and citations only: the four drift modes, the twelve checks, their thresholds and the scoring are unchanged. No rule, threshold or weight changed.

Source: Designesy drift contract v0.1.1; designesy-org pull requests 153 (3d62df0) and 283 (6d75289)

Three edits shipped under 0.1.0 without a version. On 2026-08-03 an open question that named an internal rule ID now names the HyperFrames quality gate in plain words, and the full_contract_path field, which carried an internal file path, left the export. On 2026-09-28 the purpose dropped the words "not ornament", standard 1 says to use contract cubicBezier tokens "instead of bare CSS keywords", and em dashes became colons across the Lottie fields, the version notes, the reduced-motion notes and relationship_to_core.

Wording, and one field removed from the export. The ten motion standards, the checks, their thresholds and the scoring are unchanged. No rule, threshold or weight changed.

Source: Designesy motion contract v0.1.1; commits fb550a4 and 7f6d098, designesy-org pull request 153 (3d62df0)

Three edits shipped under 0.1.0 without a version. On 2026-08-30 the composition, the score dimension, rp02 and relationship_to_core moved from a 40-check to a 42-check score engine. On 2026-09-24 those four places began reading the engine's check count instead of a typed number, with the same served text, and the count has since followed engine releases. On 2026-09-28 em dashes became colons or parentheses throughout, the rp08 warn band reads "20 to 30 points" where it used a dash, and "clearer signal" became "clearer result". This version also drops the "2026 crisis" claim from the weighting rationale, as drift's purpose did in #283: drift is second because it measures how far AI-generated UI departs from its declared system.

The weights (score 0.5, drift 0.3, readiness 0.2), the eight synthesis checks, the coherence thresholds (20 and 30 points) and the grade bands are unchanged. The check count states the size of the score engine, which the engine entries above record. No rule, threshold or weight changed.

Source: Designesy report contract v0.1.1; commit fe77f42, designesy-org pull requests 119 (d53eeae) and 153 (3d62df0)

A new check, v46, reads the type scale from a page's own :root type tokens (their values plus their median ratio) and judges every static rem or px font-size against it: off the scale when it sits more than 2.5% from every step, under the floor when it is smaller than the smallest type token. Deliberate fluid type, a clamp(), min() or max() that moves with a viewport or container unit, is accepted as written; only its lower bound is held to the floor. It WARNs, it never FAILs. The registry grows to 45 checks, 42 scored.

v16 asks for rem and cannot tell a rem on the scale from one between steps, so a page could pass it while its sizes drifted off the scale its own tokens declare. Measured on this site the day it shipped: v46 WARNs on 7 sizes under the 12.8px floor and 7 between steps, the display numerals and home rules this site's own type gate lists as deliberate exceptions. Fluid section titles pass as written.

Source: Brand ledger D59 and D68 (the Major Third scale and its floor), CSS Values 4 (clamp, min, max, viewport and container units), engine 1.4.0 entry in CHANGELOG.md

v27 found the word input, textarea or select and then the next rule, across a closing brace, so "select" in user-select: none made the following rule a field rule and a 12px caption failed the page. It now reads each font-size against the selector of the rule it sits in. A class that names a field still counts, and select { font-size: 14px } still fails. v37 is renamed "DESIGN.md spec-layer validation (DESIGN.md format lint)", and its fix text names the format's linter; the install and run commands are unchanged.

A FAIL on a page whose fields are right is a wrong reading, and it caps the grade. Removing it raises the affected scores: measured on the leaderboard cohort on the same bytes, two sites move up, one by a full grade where the false FAIL had pulled its accessibility checks under the 60% cap. No score goes down. The leaderboard shows the new scores from its next weekly re-score. This site stays 100 A, and a real field under 16px still fails.

Source: engine 1.4.1 entry in CHANGELOG.md; brand ledger D75 (the DESIGN.md format named in prose)

Atkinson Hyperlegible Mono replaces Geist Mono for labels, URLs, timestamps, score units and code. The type scale becomes six tokens on a Major Third over a 16px root: --text-label 0.8rem, the floor for all text, --text-body 1rem, --text-lead 1.25rem, --text-h3 1.563rem, --text-h2 1.953rem and --text-h1 2.441rem, no two adjacent steps closer than 25%.

The mono text on this site is the text a reader cannot guess from context: hosts, check IDs, scores and dates. Atkinson Hyperlegible Mono is the Braille Institute's face for low-vision readers, and it draws every confusable pair (0 and O, 1, l and I, 5 and S, 8 and B) distinct. Named sizes replace one-off values, so a page cannot drift off the scale. No check, weight or verdict changed.

Source: Designesy design system contract v0.4.5, adoption history; Atkinson Hyperlegible Mono 2.001 (SIL Open Font License 1.1)

v26 no longer counts a face named with the word fallback, such as a metric-matched stand-in drawn only until the real face loads, as a typeface choice. v27 reads font-size: var(--token) in a field rule through the :root tokens, so a field set to a 1rem token is the 16px floor it renders as, and one set to a 0.875rem token fails. v38 drops the keycaps a button marks up as kbd, and plain ctrl+s style hints in any case, from button labels, and accepts Get, Set, Try and a short list of call-to-action verbs (Flip, Learn, Sign, Join, Expand, Select, Read). v43 counts --destructive, the error role in shadcn/ui, as an error colour. The npm engine stops after three redirects instead of following a loop.

Each defect was a warning on a page that was right, this site among them: four families counted where three render, a 16px input read as unset, and a keycap button read as the words ctrl and i. A warning on correct work teaches readers to ignore warnings. v42 is unchanged: Tailwind v4 writes only the theme variables a project uses, so a sheet full of hue-named tokens is using them.

Source: engine 1.3.1 entry in CHANGELOG.md; Tailwind CSS v4 theme documentation (only used CSS variables are generated); shadcn/ui theming (--destructive)

axe_tag and a01 now list wcag2a, wcag2aa, wcag21a, wcag21aa and wcag22aa, and the Playwright and CLI commands pass all five. 0.1.1 named wcag22aa as if it included the others, and its commands passed wcag2a, wcag21aa and wcag22aa. axe-core tags are not cumulative: wcag22aa alone marks only the WCAG 2.2 AA additions. rules_in_scope changed from "~75+ rules" to a count: 70 axe-core 4.13.0 rules carry one of the five tags (counted on 2026-10-11).

This changed what a01 measures: a run with the 0.1.1 tags left out the rules tagged wcag2aa and wcag21a. The pass and fail conditions (0 violations, any violation) did not change.

Source: Designesy a11y contract v0.1.2; designesy-org pull request 281 (83d1bcf)

m01 changed from "Schedule registered: URL + cadence recorded" to "History supplied": the request carries earlier runs to compare against, and nothing is scheduled or stored on the server. With no history m01 is N/A, because a first run sets the baseline. Scoring does not count that SKIP: the score is points over scored checks, where it divided by 10.

Rules changed: m01 checks what the engine does, which is compare against history passed in, and the scoring denominator.

Source: Designesy monitor contract v0.1.2; designesy-org pull request 281 (83d1bcf)

m02 changed. It passes when the newest supplied run is within one cadence window (daily, weekly or monthly; weekly by default), warns between one and two windows, fails past two, and is N/A with no history or no usable timestamp. In 0.1.2 it said only that the last run fell within the cadence window. A SKIP of m02 on a first run is not scored. Earlier the same day, pull request 283 corrected how the contract describes monitor: each call re-runs the drift checks and compares the result with the history the caller passes in, nothing is scheduled, and the server keeps no history. In the same edit two quoted sources were re-quoted and re-attributed, a third was removed, and the competitor line became a description of the method.

Rules changed: the m02 thresholds, and the scoring of a first run. The description edit from pull request 283 changed no check.

Source: Designesy monitor contract v0.1.3; designesy-org pull requests 297 (7190efc) and 283 (6d75289)

A page with a failing check can no longer score an A: any FAIL caps the score at 89.9, a B, and every cap applies after the originality lift, which can carry a score up to a cap but never past it. v44, status colors used as text, caps at 65 as v06 does. v34 fails only a chat surface that names itself a chatbot or an AI assistant; a live-chat widget, an ad tag or page text about AI is at most a review item, and its text cites California SB 1001 and Colorado SB 26-189 and names Article 50(1) as a duty on the provider of the AI system. v06 and v22 read oklch(), space-syntax rgb() and hsl(), 8-digit hex, and tokens declared as :root, :host. v42 and v43 follow var() aliases, and hue-named primitives that role tokens alias form the palette layer, which sits outside the role share.

The engine could report its own failing WCAG contrast check and an A for the same page, and its review printed Block and Grade A together. A grade beside its own failing verdict says two things at once, so the owner chose the stricter reading.

Source: Owner decision (2026-10-11), WCAG 2.2 SC 1.4.3 and 1.4.11, EU AI Act Article 50, California Bus. & Prof. Code §17940-17943, Colorado SB 26-189, CSS Color 4, engine 1.3.0 entry in CHANGELOG.md

Azure #0A94FF replaces the previous blue as --signal. In the light theme, text, links, focus and selected states take Deep Azure #016ABB (--signal-access, --signal-deep), and text on an Azure fill is ink #010102 (--paper-on-signal, 6.65 to 1). Activated Orange #F56B00 replaces the previous yellow (light text #B04D00), and grade D moves to rose. New tokens: --signal-deep, --signal-teal, --action, --on-action, --action-pressed and --paper-white.

The contract states the identity v1 colour system that designesy.org serves. It changes token values only: no check, weight or verdict changed.

Source: Designesy design system contract v0.4.4, adoption history

Scoring counts a WARN as 0.5 where 0.1.1 counted it 0: score = (PASS + 0.5 × WARN) / scored checks × 100, as in the motion contract, the score engine and the npm validator. t08 resolves a {group.token} alias to the dimension it points at, and a $root token is checked like any other. The open item on aliases now says t08 resolves them on dimension tokens and that checking every alias target type is not wired. live_export states 9 PASS, 0 WARN, 0 FAIL and t07 SKIP, and describes the export's DTCG values.

Rules changed: the WARN weight in the scoring formula, and how t08 reads aliases.

Source: Designesy tokens contract v0.1.2; designesy-org pull request 258 (e10ed5f)

m09 changed: it compares the design contract version the run is scored against (the version designesy_score reports), where 0.1.0 read the scanned site's own DTCG or agent.json version, which on designesy.org is the catalog version. Snapshots do not record that version yet, so a change between runs is stated rather than compared. An edit that shipped under 0.1.0 without a version is recorded here too: on 2026-08-02 m10 changed from a webhook, email or Slack alert to an email alert, and an alert_delivery section says when email is sent and that alerts show on the page when it is not. On 2026-09-28 an editorial pass replaced em dashes.

Rules changed: what m09 compares, and the delivery channel m10 checks.

Source: Designesy monitor contract v0.1.1; designesy-org pull request 254 (f4f9a51), with commit b1e1e66 and pull request 153 (3d62df0)

Edits that shipped under 0.1.0 without a version come first. On 2026-08-30 the ten checks were replaced with the ten that designesy_tokens_score runs: t01 $schema declared, t02 token groups, t03 $type, t04 $value, t05 structured colour, t06 standard types, t07 namespaced custom types, t08 dimension units, t09 nested groups, t10 no deprecated patterns. $schema moved from SHOULD to MUST, scoring counted a WARN as 0 where it had counted 0.5, and the five rules the engine does not check moved to documented_not_engine_wired. Before that, on 2026-08-03 the full_contract_path field, which carried an internal file path, left the export, and on 2026-08-09 a live_export line was added. On 2026-09-28 an editorial pass replaced em dashes. The 0.1.1 edit itself: a SKIP is not scored (it had counted in the denominator, so a clean file with no custom types scored 90), and live_export reports the DTCG export at 100 with t07 SKIP.

Rules changed: the check list, the $schema requirement and the scoring formula. Each edit is recorded here because none had a version or a changelog line when it shipped.

Source: Designesy tokens contract v0.1.1; designesy-org pull request 254 (f4f9a51), with commits 7f6d098, ed99914, 7f8e7d4 and pull request 153 (3d62df0)

Each status, grade and activation hue gains a text token, --<hue>-ink: the hue itself in the dark theme, and in the light theme the hue mixed toward ink until it reads at 4.5 to 1 or better on every surface. Light --muted-dim darkens from #70707a to #686872. Dots, bars, borders and tints keep the hue.

A rendered sweep of every public page found 230 text elements under WCAG AA in the light theme and 11 in the dark. Nearly all were one mistake repeated: a colour chosen to mark a state (3 to 1 is enough for an icon) used to write the word for it (text needs 4.5 to 1). A text token per hue makes the right choice the default, and the site build now fails on a bare hue used as text.

Source: WCAG 2.2 SC 1.4.3 and 1.4.11, rendered contrast sweep of designesy.org (2026-10-08), CSS Color 5 color-mix()

v44 measures every status color a stylesheet uses as text, in every theme it declares, and fails a status-named color with a hue that reads under 4.5 to 1 (3 to 1 for large text, an icon or a bar) on a surface the stylesheet attests; where it cannot attest the surface, or the text is white or grey, it warns. v45 fails an entrance that starts at opacity 0 and stays held invisible when a visitor pauses motion. Every score gains both, so the engine runs 44 checks. The S2 and S8 anti-slop rules stop deducting for components and prose, and the npm engine caps scores by the same accessibility floor as the site.

Both defects shipped on this site and passed every check the engine had: the CSS was valid and the default view looked right. The light warning color wrote status words at 3.51 to 1, and the pause control emptied whole pages for the visitors who had asked for less motion. A check that catches its own author is the one worth publishing.

Source: WCAG 2.2 SC 1.4.3 and 2.2.2, CSS Animations Level 1 (animation-play-state), engine 1.2.0 entry in CHANGELOG.md

v05 passes a site that declares its motion only inside prefers-reduced-motion: no-preference, provided the block opts into motion; an empty block, or one that only switches motion off, still warns. v27 reads N/A on a page with no text input, textarea or select when its CSS sets no input font size. v14 and v18 join the optional tier, so an external site that does not adopt the Cadence rules is skipped on them. The MCP token validator checks against the 13 types DTCG 2025.10 defines. Scored on pages captured from the 30 leaderboard sites on 2026-10-08, 21 change at least one verdict.

Each fix removes a verdict the engine could not defend. Gating motion behind no-preference is a recommended way to honour reduced motion; a page with no field gives iOS nothing to zoom into; and v14 and v18 judged external sites on Designesy taste under the scope meant to be fair to them. The engine version moves so a score from before the fix and one from after it can be told apart.

Source: Media Queries Level 5 (prefers-reduced-motion), DTCG Format Module 2025.10, engine 1.1.0 entry in CHANGELOG.md

The header, the page wrappers and the footer now share the content edges at every width, so nothing sits on a different gutter than the thing above it. A 12-column grid with a named 7|5 seam replaces the per-page split rules. The material, elevation and floor recipes became tokens rather than values repeated per component. The WCAG 2.2 AA pass added the accessibility tint tokens, including --signal-text as the text-safe role for the brand blue. The reduced-motion tiering is stated as it now behaves: movement stops, opacity fades and transitions of 200ms or less stay.

The site described one alignment system and implemented four, and the disagreement was invisible to every automated check because none of them compared one region's edge to another's. The accessibility tokens close a measured contrast failure: the brand blue as text read 2.0 to 2.3 to 1 in dark mode against a 4.5 to 1 minimum. Naming the motion tiering settles a documented conflict between two readings of the same clause.

Source: Designesy a11y contract v0.1.1, WCAG 2.2 AA (2.4.11, 1.4.3, 2.5.8), edge-contract measurements

a10 changed. Under 0.1.0 it read "prefers-reduced-motion disables animations" and passed when a reduced-motion rule was present, failing when it was missing. Under 0.1.1 it passes only when nothing translates, rotates, scales or pans for longer than 200 ms or in a loop under reduce, and fails when movement continues. Opacity-only fades may continue, and demos whose motion is the content play on request. Edits that shipped under 0.1.0 without a version are recorded here too: on 2026-08-03 a11 named internal control-plane names where it said internal naming, and the full_contract_path field, which carried an internal file path, left the export; on 2026-08-30 the named axe-core version moved from 4.12.1 to 4.13.0; on 2026-09-28 an editorial pass replaced em dashes.

This version changed a rule: a10 used to pass on the presence of a reduced-motion block and now passes on what moves under reduce, as the motion contract requires.

Source: Designesy a11y contract v0.1.1; designesy-org pull request 173 (66f51e5), with commits fb550a4, 7f6d098, d2cc52e and pull request 153 (3d62df0)

The contract modules and the /contracts pages were revised together. A colon or parentheses replaces the em dash, the positive claim replaces rhetorical negation pivots, and number ranges read "to". No rule, value, token or check changed. The sibling contracts took the same pass and keep their versions.

The contract asks product copy to state its claim plainly and to write ranges a screen reader can read: an unspaced en dash is skipped, so a range written with one is heard as two bare numbers. A patch version marks text that changed while every rule stayed the same.

Source: Designesy public-copy rules, GOV.UK style guide, plainlanguage.gov, NVDA symbol handling

The semantic category carried a reserved weight (12) with zero checks since v0.3.0. Two deterministic checks now score it: v42 measures the role-named vs hue-named share of :root color tokens; v43 checks status-state coverage (ok/warn/error/info). Engine grows 40 → 42 checks.

The contract's own palette is fully role-named (--ink, --paper, --surface, --signal, --ok/--warn/--error): color named by meaning rather than wavelength. Role-based naming is the documented best practice (zeroheight naming guide, Material 3), but nothing scored it. Both checks are WARN-only (style craft with no user harm) and self-SKIP when a site has no color tokens.

Source: Designesy contract colors section, zeroheight naming guide 2026, Material 3 design tokens

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. Weight 8 of 117 (6.8% of the score). 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 the DESIGN.md spec file with the DESIGN.md format's linter. Integrates the spec layer beneath designesy's own contract verification.

DESIGN.md is the AI-agent-facing spec file. With it, AI coding tools build from your system instead of around 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 v0.2.2 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. Weight 18 of 117 (15.4% of the score), the heaviest 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. Weight 9 of 117 (7.7% of the score).

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. Weight 15 of 117 (12.8% of the score).

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.

Homoglyph attacks in CSS identifiers can spoof brand colors and redirect trust, and a linter that reads values does not read names.

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