onsystem MCP server

Read from the package source without running it. The installed server may list more.

• check_ui

  Lint TSX/JSX against the design system. Reports hardcoded colors, spacing and radius (with the nearest token), native elements that have a design-system component, unknown components, props and variant values, and icon-only buttons without an accessible name. Each diagnostic has line/column, a rule id, a message and a suggested fix. Run it on every snippet or file you write and fix all errors. Pas

• get_component

  Get the full contract of one component: import, props with types and defaults, cva variants and the classes each applies, parts (sub-components), design tokens it uses, usage guidelines and examples from its docs. Call it before using a component. Accepts "Button", "CardHeader" or "Card.Header". At a monorepo root, pass `path` (the file you are editing) to get the component its project uses.

• get_tokens

  List design tokens with resolved values, dark-mode values and how to use each (Tailwind class or CSS variable). Filter by category (color, spacing, radius, typography, shadow, other) or a substring. Use these instead of hex codes, px values or Tailwind default palette classes.

• list_components

  List every component in the project design system with a one-line description, the native element it renders, its variant values, its parts and its import. Call this before writing UI in this project. At a monorepo root, pass `path` for the project of the file you are editing; without it, every project is listed, each component with its package.

• search_components

  Find components by what you want to build, e.g. "confirm a destructive action", "status label", "text field with validation". Ranks names, descriptions, docs, props and variant values with BM25 (local, no API key). Use it when you do not know which component fits.

• Code scan14 source files scanned25/25
• –Live reliabilityno gateway calls yet and no remote to proben/a
• –Tool poisoningtools not inspected (local package is not executed); not countedn/a
• Auth qualitylocal package, no credentials required12/15
• Maintenancelast push 0 days ago15/15
• Maintainer identityregistry namespace matches repository owner; GitHub account older than a year8/10

onsystem: common questions

Is onsystem MCP server safe?

Yes, by our scan: it is graded A (92/100). Read the onsystem safety report

How do I install onsystem?

It runs on your machine. Copy the Claude Code, Cursor, VS Code or Claude Desktop config from the install section.

Does onsystem need an API key?

Not as far as the registry entry and our scan can tell: no credentials are declared or required.

Is onsystem maintained?

The last commit was in the last day (2026-10-12). The latest release is v0.6.0.

What can I use instead of onsystem?

Servers from other publishers that do the same job: Dembrandt MCP server, melta UI MCP server and TypeUI MCP server. Compare all onsystem alternatives.