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Storefront → Templates → Migration validation

Parity overview

A CLI that captures a live storefront into an agent-ready bundle and validates a migrated site against the original.

@decocms/parity is a Playwright-based CLI with two jobs in a migration:

  • Capture — point it at a live storefront URL and it extracts the theme, fonts, logo/icons, per-component HTML (+ suggested Tailwind + e2e selectors) and, for VTEX IO, the real block tree and CMS content, into a token-lean, agent-ready bundle.
  • Validate — give it two URLs (prod = source of truth, cand = the migrated site) and it reports UI, functional, SEO, performance, console, network and cache regressions with an LLM-ranked report.

Capture works whether or not you have the source code — it reads the rendered page. It's the fastest way to start a migration from a store you only have a URL for.

Install

# Global (auto-installs Playwright Chromium on first run)
npm i -g @decocms/parity
 
# Or run without installing
npx @decocms/parity run --prod https://old.com --cand https://new.dev --preset smoke --open

Set ANTHROPIC_API_KEY (or OPENROUTER_API_KEY) to enable the LLM passes (issue ranking, visual semantic diff, selector discovery). Everything degrades gracefully without a key — see Configuration.

The command families

FamilyCommandsUse it to…
Validate (prod × cand)run, journey, pr, compareCompare a migrated site to the original and gate a PR.
Pixel-perfectfix, sectionDiff one section (screenshots + heatmap + computed styles) into an LLM-ready bundle.
Performancevitals, cacheCompare Web Vitals / cache coverage across many pages.
Single-sitee2e, auditValidate ONE site end-to-end (no baseline).
Capturemigrate, extractExtract a store into a migration/agent bundle.
Inspectcss-trace, console, html, checkSub-10s single-purpose probes.
Manageserve, report, baseline, list, prompt, explain, learnedWork with saved runs + artifacts.

Which command?

See also