Hallmark Adds Anti-Slop Design Linter and Themes to Agentic IDEs

01Eliminating AI Design Tells

Frontier coding agents produce competent markup but frequently repeat visual tells: eyebrow tags above every title, colored words in headlines, and trailing email sign-up boxes on unrelated pages. Hallmark enforces layout rules that discard these defaults. Rather than hallucinating content, its pre-flight phase inspects local fonts, frameworks, and design tokens, pulling assets from a verified database of 755 openly licensed Wikimedia Commons photos instead of restricted stock platforms.

02Multi-Tier Gates and Browser Linting

Hallmark inspects output through three distinct gate stages:

• The Floor: Non-negotiable checks that never ship if contrast, focus, reduced motion, invented facts, or phone layouts fail.
• Reflex Gates: Targets predictable defaults models fall into; builds with a documented reason may explicitly overrule them on the record.
• Finish Checks: Polishes typography, surface treatments, and micro-spacing without halting compilation.

Running node skills/hallmark/scripts/sloplint.mjs <file> --render executes Puppeteer against eight viewport sizes, after which a clean-context subagent audits the rendered viewports.

03Non-Destructive Refactoring

When modernizing existing interfaces, /hallmark redesign <path> ensures functionality remains intact. The system runs sloplint --before to snapshot every link, input, and interactive handler. If any interactive element is dropped during the restyle, sloplint --kept fails the build, presenting a side-by-side diff before handoff.