Slim Guard MCP Server

MCP Slim Guard gives a host one deliberate way to reach authorized upstream tools. It keeps input schemas intact, validates calls before the upstream is invoked, and can recover an oversized result exactly without repeating that invocation. It runs locally over stdio via the published package.

People connecting this server to Claude, Cursor, VS Code, or another MCP client. The project is written in TypeScript.

VERIFIED ACTIVE

LAST COMMIT 2026-08-14 · ★ 132 · #131 OF 848 MAINTAINED OTHER · VERIFIED 2026-08-25

MIT · TypeScript servers · how we verify → /methodology

01 · Install Slim Guard

Claude Code

claude mcp add lennney-mcp-slim-guard -- npx -y mcp-slim-guard

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "lennney-mcp-slim-guard": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-slim-guard"
      ]
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions

repo age created 2026-07-31 - young repo, little track record yet

license MIT - declared in the repository

npm package mcp-slim-guard - unscoped; check the name against the project README before installing

registry namespace io.github.lennney is GitHub-verified and matches the repo owner

03 · What Slim Guard can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

Latest releases

v0.1.0 · 2026-07-31

mcp-slim-guard v0.1.0 · The control plane between AI agents and MCP servers. · Reclaim ~83% of MCP tool-schema context without changing your existing servers - and verify the result yourself. · Key Features · 5-level…

04 · Who maintains Slim Guard

mcp-slim-guard is maintained by lennney. We track 2 MCP servers from lennney - 2 actively maintained, 239 combined GitHub stars, oldest repo from Jun 2026. Full record: all servers from lennney.

agent-search-mcp Free-first Chinese and English web search MCP using zero-key sources and inspectable evidence. ★ 107

05 · Facts

repository: github.com/lennney/mcp-slim-guard
category: other - ranked #131 of 848 actively-maintained other servers as of 2026-08-25.
release cadence: 1 release in the last 90 days (latest 2026-07-31)
registry: io.github.lennney/mcp-slim-guard (active, first published 2026-07-23 · 2 versions)
packages: npm:mcp-slim-guard

06 · Slim Guard FAQ

What is Slim Guard?

Is Slim Guard still maintained?

Yes - as of 2026-08-25, its last commit was 2026-08-14 and it shipped 1 release in the last 90 days. We re-verify nightly.

How do I install Slim Guard?

Run `npx -y mcp-slim-guard`. You can also paste the ready-made client config above.

Does Slim Guard run locally?

Yes - it's a stdio server: it runs on your machine (via npx) with your user's permissions. Your data stays local unless the server itself calls external APIs.

07 · Alternatives to Slim Guard

Alternatives to Slim Guard

Maintained other servers if Slim Guard isn't the fit.

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