Fetter MCP

A remote Model Context Protocol (MCP) server (https://mcp.fetter.io/mcp) that gives AI coding agents real-time access to Python package vulnerability data. Built on fetter, it queries PyPI and OSV to surface known CVEs, CVSS scores, and safe versions so your agent can make informed dependency decisions as it writes code.

Features

most_recent_not_vulnerable

Find the most recent version of a package that has no known vulnerabilities. Provide only a package name (e.g., "requests"), and the server will search recent releases for a safe version.

is_vulnerable

Check if a specific package version has known vulnerabilities. Requires an exact version specifier (e.g., "requests==2.31.0").

• Returns vulnerability IDs, summaries, CVSS scores, severity ratings, and reference URLs

lookup

Look up a package by name and (optionally) version specifier to find which versions are available and whether they have known vulnerabilities.

• Supports version specifiers: "requests", "numpy>=2.0", "flask==3.0.0"
• Filter results by CVSS score threshold, or show only the maximum observed score
• Limit the number of recent versions checked
• Optionally retain results for versions with no vulnerabilities

Installation

Claude Code

claude mcp add --transport http fetter https://mcp.fetter.io/mcp

Codex

codex mcp add fetter --url https://mcp.fetter.io/mcp