Why dscheck

Every team with a design system has the same unspoken promise: UI uses a finite set of values. Almost nothing enforces it. The linters that try either accept any var() without knowing which tokens are real, or are hard-wired to one company’s system. Meanwhile coding agents now write a growing share of UI — and they fabricate plausible values constantly: #3b82f6 instead of var(--color-primary), a --color-primary-500 that doesn’t exist. dscheck exists to make the promise checkable.

Three commitments

Never guess. dscheck reports what it can prove and stays silent otherwise. Interpolated declarations, dynamic classnames, calc() internals — skipped, on purpose, and every skip is documented and fixture-tested on the supported surfaces page. Silence that means “didn’t check” is never allowed to look like “checked and passed”: files that fail to parse surface as findings.

Never lie. A finding on a supported surface is always a real off-system value. That claim is enforced, not aspired to: a pinned corpus of real repositories runs nightly with human-audited samples, and every false positive ever found becomes a permanent regression fixture. The release scoreboard tracks confirmed false positives per release — 1.0 is declared from that evidence.

Never damage. fix applies only provably-identical replacements. 14px is never rounded to 12px; a near-miss becomes an editor suggestion a human accepts. Fix output is property-tested to reparse, converge, and never surprise a diff.

Why suggestions carry distances

use var(--spacing-3) (12px, Δ2px) is not decoration. For a human it turns a violation into a one-keystroke decision. For an agent it closes the loop: the guardrail hook feeds findings back, and the agent applies the named token instead of guessing again. Measured on an identical component task: 19 off-system values without the hook, 0 with it.

Why there’s no dscheck platform

The design-system tooling graveyard is real — hosted platforms in this space have died repeatedly, taking their users’ workflows with them. dscheck is the opposite bet: plugins for the linters you already run, a CLI, one optional dotfile, no servers, no telemetry, no accounts. Everything reproducible from the repository alone. Boring on purpose, so it’s still working in five years.