CSSSAFE
Overview
From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.
An MCP (Model Context Protocol) server that provides up-to-date CSS documentation from MDN and comprehensive CSS code analysis.
Features
Documentation & Compatibility:
- Official MDN Docs - Fetches documentation directly from MDN's API
- Browser Compatibility - Includes browser support data from MDN's BCD
- Simple API - Just pass CSS property names like
"grid","flexbox", or":has" - Markdown Conversion - Converts HTML documentation to clean, readable markdown
- Auto-normalization - Supports both simple slugs (
"grid") and full paths ("Web/CSS/grid") - Smart Caching - SQLite-based cache with 7-day TTL for blazing-fast responses
CSS Analysis:
- 150+ Metrics - Comprehensive analysis of stylesheet quality and complexity
- Design Patterns - Detect color palettes, font sizes, spacing patterns
- Code Quality - Selector complexity, specificity analysis, property usage
- Performance Insights - Identify overly complex selectors and redundant code
Installation
For Claude Code
Install via the Claude Code CLI:
claude mcp add css -- npx -y css-mcp
For VS Code
One click install:
[](https://vscode.dev/redirect/mcp/install?name=css&config=%7B%22name%22%3A%22css-mcp%22%2C%22command%22%3A%22npx%22%2C%22args%22%3A%5B%22-y%22%2C%22css-mcp%22%5D%2C%22env%22%3A%7B%7D%7D) [](https://insiders.vscode.dev/redirect/mcp/install?name=css&config=%7B%22name%22%3A%22css%22%2C%22command%22%3A%22npx%22%2C%22args%22%3A%5B%22-y%22%2C%22css-mcp%22%5D%2C%22env%22%3A%7B%7D%7D&quality=insiders)
Install via VS Code CLI:
code --add-mcp '{\"name\":\"css\",\"command\":\"npx\",\"args\":[\"-y\",\"css-mcp\"],\"env\":{}}'For MCP Clien
57346dfa5b5bOBSERVED · 2026-10-03Connect
Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control.
claude mcp add css-mcp -- npx -y [email protected]
{
"mcpServers": {
"css-mcp": {
"command": "npx",
"args": [
"-y",
"[email protected]"
]
}
}
}Exposed tools (4)
4 read · 0 write · 0 destructive.
| Tool | Risk | Description |
|---|---|---|
analyze_css | read | Analyze CSS code for quality, complexity, and design patterns. Returns curated summary by default (lightweight, ~1-2k tokens) or full 150+ metrics with summaryOnly: false. Use this to identify issues, suggest improvements, or audit CSS codebases. |
analyze_project_css | read | Analyze all CSS files in a project directory. Finds all .css files recursively, combines them, and analyzes as a whole. Accepts: single file path, directory path, or glob pattern (e.g., |
get_browser_compatibility | read | Get browser support data for CSS features. Use this tool when the user needs to know browser compatibility, or when suggesting modern CSS features that may need fallbacks. Format: |
get_docs | read | Fetch official MDN documentation for any CSS property, selector, function, or concept. Use this tool PROACTIVELY whenever the user mentions CSS features. Supports simple slugs (auto-normalized): |
Trust audit
SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.
| Layer | What it checks | Result |
|---|---|---|
| L0 | Provenance & inventory | PASS |
| L1 | Static analysis of the code | PASS |
| L2 | Instruction surface (what it tells the agent) | PASS |
| L3 | Class-specific surface | PASS |
| L4 | Behavioural (sandbox) | SKIPPED |
What the source does
- Filesystem
- none-observed
- Network
- declared (1 observation(s))
- Shell
- none-observed
- Dependencies
- not all pinned
- Secrets in source
- none-found
Findings (2)
@modelcontextprotocol/sdk, @projectwallace/css-analyzer, better-sqlite3, fast-glob, turndown, zod
Gates applied: no_behavioural_pass, no_license.
57346dfa5b5bfull audit observations/trust-audit/mcp-server/stolinski__css.json · Report an issue / request a re-scanAudit history
Every audit this server has had. A grade with a past is a grade somebody is still checking.
| Date | Source | Verdict | Grade | Score | Change |
|---|---|---|---|---|---|
| 2026-10-03 | 57346dfa5b5b | SAFE | B | 89 | first audit |
Questions
What tools does CSS expose?
4 in total: 4 read-only, 0 that write, and 0 that can delete or overwrite. Every one is listed on this page with its risk.
Is CSS safe to connect to an agent?
The audit found nothing in the source that contradicts what it says it does, and graded it B (89/100). Grade A is held back for packages that have also passed a sandboxed behavioural run, which is why a clean server reads B.
What credentials does CSS need?
No credential environment variables were found in its source, so it appears to need none.
How does CSS run?
It speaks stdio, so it runs as a local process your client starts. It is published on npm as css-mcp at 1.3.0.
How current is this page?
The grade is for one exact copy of the source (57346dfa5b5b), read on 2026-10-03. The repository is watched and re-audited when it changes.