jp-web-design-guardrails vs Japan Data MCP
jp-web-design-guardrails is a plugin bundle for AI coding tools published by mrslbt. Marketplaces we read that list it: 1 (Claude Code: claude-plugins-community). Japan Data MCP is an MCP server published by Mameta29. Marketplaces we read that list it: 1 (Official MCP Registry). As of our marketplace pass on 2026-11-10. This pair was picked by a reader, not by our comparison rule, so search engines are asked not to index the page.
Where each is published
| Marketplace |  jp-web-design-guardrails |  Japan Data MCP |
|---|---|---|
| Claude Code: claude-plugins-community | Listed Version: 1.0.0 Forks (GitHub): 1 Stars (GitHub): 1 Not marked · First seen |
Not listed |
| Official MCP Registry | Not listed | Listed Version: 1.1.0 Downloads/month (npm): 184 Downloads/week (npm): 58 Forks (GitHub): 0 Stars (GitHub): 2 Not marked · First seen |
Each figure is the marketplace's own and is never added up across marketplaces. A marketplace that publishes no figure shows none: no number is not zero.
The facts side by side
| Fact | jp-web-design-guardrails | Japan Data MCP |
|---|---|---|
| Marketplaces that list it | 1 | 1 |
| Stars (GitHub) (differs) | 1 (worse) | 2 (better) |
| Forks (GitHub) (differs) | 1 (better) | 0 (worse) |
| Last release | Not published | Not published |
| Where it runs (differs) | Installs as a plugin bundle | On your machine (@mameta/japan-data-mcp) |
| Transport (differs) | Not stated | stdio |
| Tools it declares | Not published | Not published |
| Environment variables it asks for (differs) | Not published | 1, secrets among them: 1 |
| Parts of the bundle (differs) | 1 | Not a bundle |
| Licence | Not stated | Not stated |
| Repository (differs) | github.com/mrslbt/jp-web-design-guardrails | github.com/mameta29/japan-data-mcp |
| Changes in the last 7 days | 0 | 0 |
| First seen | 2026-10-11 | 2026-10-11 |
Lines where the two differ have a tinted background and bold values. Where the data itself says which value is better (more marketplaces, a larger figure of the same marketplace, a fresher release, a verified mark on a marketplace that lists both), the better one is also marked green with ▲ and the worse one red with ▼. Where it runs, the transport, the tools, the settings, hooks, the bundle's parts, the licence and the week's changes are marked only as different: more or fewer is not better in itself.
What each says it does
jp-web-design-guardrails
Guardrails for building Japanese-ready web interfaces. Automatically enforces correct CJK typography (font stacks, line-height, kinsoku shori), Japanese form conventions (furigana fields, postal code auto-fill, Imperial era dates, confirmation screens), honorific-aware UX copy, seasonal color themes, accessibility (JIS X 8341-3), and production-ready CSS. Prevents common mistakes like using italic for emphasis, wrong name field order, and loading full CJK font files.
Japan Data MCP
30 tools for Japanese data: address, furigana, transit, Diet, holidays, weather, corporate registry
How to run each
jp-web-design-guardrails As a Claude Code plugin
/plugin marketplace add anthropics/claude-plugins-community
/plugin install jp-web-design-guardrails@claude-communityJapan Data MCP As a local MCP server: npm package
claude mcp add --env "EVM_PRIVATE_KEY=<YOUR_EVM_PRIVATE_KEY>" --transport stdio japan-data-mcp -- npx -y @mameta/japan-data-mcpRequires: EVM_PRIVATE_KEY (secret)
Commands built only from what the marketplaces declare; the full set for every client is on each card.
Tools each declares
Neither one's marketplaces publish a list of tools, so there is nothing to compare.
Settings each asks for
The marketplaces of jp-web-design-guardrails publish no settings it asks for, so we do not compare settings.
What it can do: jp-web-design-guardrails · What it can do: Japan Data MCP · Compare two other plugins
Data comes from the public marketplace file https://github.com/anthropics/claude-plugins-community/blob/HEAD/.claude-plugin/marketplace.json. Data comes from the Official MCP Registry (registry.modelcontextprotocol.io), CC0 1.0. Figures come from our own regular passes over the marketplaces, last read on . We publish no contact details for plugin publishers.