MCP_clients

A software development kit for building clients that connect to MCP servers. MCP is a standard way for applications to discover prompts, resources, and tools and then use them through one client interface.

In plain words
What is it for?
Use it when writing an MCP client that connects over a local process, discovers available capabilities, reads resources, gets prompts, or calls server tools.
Why use it?
It removes much of the connection and message-handling code needed to communicate with an MCP server. A client can use the same interface to list resources, read them, retrieve prompts, and call tools.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/chriscarrollsmith/taskqueue-mcp/mcp_clients
Clone the repo
git clone --depth 1 https://github.com/chriscarrollsmith/taskqueue-mcp

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 249 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00249
Opus 5 $0.00000 $0.00125
Sonnet 5 $0.00000 $0.00050
Haiku 4.5 $0.00000 $0.00025

Measured 2d ago against content hash 6e861f81f5d0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

MCP_clients scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/MCP_clients.mdc · 56 lines

What it actually says

Writing MCP Clients

The SDK provides a high-level client interface:

import { Client } from "@modelcontextprotocol/sdk/client/index.js";
import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js";

const transport = new StdioClientTransport({
  command: "node",
  args: ["server.js"]
});

const client = new Client(
  {
    name: "example-client",
    version: "1.0.0"
  },
  {
    capabilities: {
      prompts: {},
      resources: {},
      tools: {}
    }
  }
);

await client.connect(transport);

// List prompts
const prompts = await client.listPrompts();

// Get a prompt
const prompt = await client.getPrompt("example-prompt", {
  arg1: "value"
});

// List resources
const resources = await client.listResources();

// Read a resource
const resource = await client.readResource("file:///example.txt");

// Call a tool
const result = await client.callTool({
  name: "example-tool",
  arguments: {
    arg1: "value"
  }
});
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 56 lines · 0 tokens per session scan A 6e861f81f5d0

Subscribe to this mod's changes

MCP_clients is a cursor rule published in the GitHub repository chriscarrollsmith/taskqueue-mcp (70 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 249 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.