Rarefaction MCP Server
by ip2kio.github.ip2k/rarefaction-lsp-mcpv0.3.1
LSP call graph for coding agents: a symbol's callers, callees, tests and live files in one call.
context tax
pending
security
97/100
cold start
pending
freshness
Active2d ago
Our reading of Rarefaction, from the data
Rarefaction is an MCP server from ip2k, listed in the official MCP Registry.
We haven't measured its tool list yet, so its token cost is unknown.
Maintenance is active: the last public signal was 2 days ago (2026-10-17).
It runs locally on your machine over stdio.
Install Rarefaction MCP server
Install in Claude Code
claude mcp add rarefaction-lsp -- npx -y rarefaction-lsp-mcpInstall in Cursor
{
"mcpServers": {
"rarefaction-lsp": {
"command": "npx",
"args": [
"-y",
"rarefaction-lsp-mcp"
]
}
}
}Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project).
Install in Claude Desktop
{
"mcpServers": {
"rarefaction-lsp": {
"command": "npx",
"args": [
"-y",
"rarefaction-lsp-mcp"
]
}
}
}Settings → Developer → Edit Config (claude_desktop_config.json), then restart.
Install in VS Code
{
"servers": {
"rarefaction-lsp": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"rarefaction-lsp-mcp"
]
}
}
}Add to .vscode/mcp.json in your workspace.
Install in Windsurf
{
"mcpServers": {
"rarefaction-lsp": {
"command": "npx",
"args": [
"-y",
"rarefaction-lsp-mcp"
]
}
}
}Add to ~/.codeium/windsurf/mcp_config.json.
Security signals
97/100 — no known issues found as of 2026-10-19, from the checks below. This is not a guarantee of safety; review what a server can do before connecting it.
Deductions
- No security policy (SECURITY.md)-3
Checks
- ✓Repository hygiene (archived, activity, license, security policy)
- ○Package metadata (install scripts, provenance) — pending
- ○Tool descriptions (prompt-injection and hidden-text heuristics) — pending
- ○Source scan (secrets, CVEs, risky code) by vectra-guard — pending
Scan it yourself before installing with vectra-guard, the open-source agent security CLI. Scoring rules
Freshness
Active — last maintenance signal 2d ago. The newest of the signals below sets the band.
Last commit (default branch)
2026-10-17 · 2d ago · GitHub
Latest release
2026-10-17 · 2d ago · GitHub · v0.3.1
Package published
no data · npm/PyPI
Registry entry updated
2026-10-17 · 2d ago · official registry · v0.3.1
FAQ
›How do I install the Rarefaction MCP server in Claude Code?
Run: claude mcp add rarefaction-lsp -- npx -y rarefaction-lsp-mcp. For Cursor, VS Code, Claude Desktop and Windsurf, use the install tabs above.
›Does Rarefaction require an API key?
No required environment variables are declared in its published metadata.
›Can I use Rarefaction as a remote (hosted) MCP server?
No hosted endpoint is published; it runs locally over stdio.
›Is Rarefaction in the official MCP registry?
Yes, as io.github.ip2k/rarefaction-lsp-mcp.
Sources and method
- Official MCP Registry entry
- updated 2026-10-17
- GitHub repository
- fetched 2026-10-19
- Package registry (npm / PyPI)
- listed
- Security signals, computed by us
- 2026-10-19
- Last checked against all sources
- 2026-10-19
The description, packages and links come from the maintainer's own published metadata. Token cost, security signals, freshness and the reading above are MCPSkillHub's own measurements; see the methodology. Spot an error? Request a correction or claim the listing.