agentskill-mcp

What it does

Your agent hits a task it can't do — read A-share market data, get a second model to audit a diff, transcribe an interview, remove a watermark, clone a site's design system. Somewhere out there is a skill file that would solve it. Finding one is the annoying part.

This server puts a small, vetted catalog inside the agent. It searches, reads the delivery facts, and tells you exactly what to run. Free items come with a direct download URL; paid ones come with a price and no sales pitch.

The catalog is agentskill.nz. It's deliberately small. Public skill directories carry hundreds of thousands of entries with no vetting — measured average quality around 6 out of 12, roughly a third carrying prompt-injection risk. Every entry here ships with what it does, what it needs to run, what it was tested against, and where it stops.

Related MCP server: SkillFlow MCP Server

Install

No install step. Point your MCP client at it:

{
  "mcpServers": {
    "agentskill": {
      "command": "npx",
      "args": ["-y", "@simonlin1212/agentskill-mcp"]
    }
  }
}

Claude Code:

claude mcp add agentskill -- npx -y @simonlin1212/agentskill-mcp

Requires Node 18+. Nothing to configure, no API key, no account. The server holds no state and writes nothing to your machine.

Tools

Search reads Chinese and English in one index, so 去水印 and remove watermark both land on the same entry. Whichever you type, results carry both names.

What the catalog contains

Four modules — Finance, Commerce, Creator, General — holding two forms:

• Install Skill — a skill file the agent loads. Copy it into the agent's skills directory.

• Deploy App — a runnable app with its own UI. Deploy it, then use it alongside the agent.

Roughly half the entries are free. Several are the packaged form of open-source repositories with a combined 16,000+ GitHub stars; where a capability builds on an upstream project, the upstream and its licence are named on the product page.

How it behaves

This is a catalog tool, not an ad slot. Three rules it keeps:

• Free means free. Where the catalog publishes a download URL, the tool hands it straight over — no account, no gate. (A free entry can occasionally have no published archive yet; it says so.)

• Paid states the price and stops. No urgency, no recommendation language. The download link for a paid item is issued after checkout, on the order page and by email.

  Concretely: anything the catalog does not explicitly mark free is treated as paid (fail closed), its download field is dropped, URLs are stripped out of its name, outcome, install, source and repository fields, and the assembled output is checked against a route allowlist. The only web addresses that survive are, on https://agentskill.nz (optionally under /zh): the site root, /products/<handle>, /collections/<handle>, /pages/<handle>, and /cart or /cart/<variant>:<qty> — each matched as a whole route, so a deeper path like /products/x/download does not qualify. Anything else — another host, plain http, a lookalike domain, /download?id=… — makes the server refuse to return that record.

  What this does not cover: a bare hostname with no scheme (evil.example/x). Catching those means treating any domain-shaped text as an address, and .md is a real TLD — SKILL.md in a delivery manifest would be rejected as a domain, breaking every paid listing. These responses are plain text, so a bare hostname only becomes a link if something downstream linkifies it.

  The gap worth naming: the catalog is cached for up to five minutes. An item that turned paid inside that window is still described from the previous snapshot — including the direct download URL it had while it was free.

• An install command is information, not authorization. get_capability — the only tool that returns an install command — says so on every call. Your agent should confirm with you before writing to your filesystem or spending your money.

The catalog URL is discovered from the site's /llms.txt at runtime rather than hardcoded, so the server keeps working when the site rotates it.

Building from source

npm install
npm run build
node test-smoke.mjs    # drives the server over real MCP stdio

test-smoke.mjs speaks the wire protocol rather than importing the module, so it catches registration and transport breakage that a unit test would miss. It also asserts that no paid item ever returns a file URL.

Changelog

See CHANGELOG.md.

Disclaimer

This server reads a catalog and returns what it says. It does not evaluate whether a capability suits your use case, and it does not execute anything. Skill files are code your agent will read and act on — review them before use, the same as any dependency.

Support

If this saved you some time ☕

License

MIT

Author: Simon Lin · X @linsizhen · Email: simonlin0423@gmail.com