agentleFS
Sign inStart free
FmarzochiFmarzochi/EGC/skills/general_part2/mcp-server-patterns/SKILL.md

mcp-server-patterns

Skill61 starsChanged 46 days agoApache-2.0View on GitHub

Build MCP servers with Node/TypeScript SDK: tools, resources, prompts, Zod validation, stdio vs Streamable HTTP. Use Context7 or official MCP docs for latest API.

  • Installs packages

We split this skill into the rules it gives an agent

5 rules. 4 are common, 0 are distinctive, and 1 is very specific to this project.

  • 4

    Common

    Most of the 33 edited versions we read keep these.

  • 0

    Distinctive

    This author's own choices. Worth a look.

  • 1

    Very specific

    Tied to their project's names, files or tools. Probably skip.

  • Common
  • Distinctive
  • Very specific
  1. Common:

    Use when: implementing a new MCP server, adding tools or resources, choosing stdio vs HTTP, upgrading the SDK, or debugging MCP …

    line 15
  2. Very specific:

    Resources: Read-only data the model can fetch (e.g.

    line 22
  3. Common:

    Keep server logic (tools + resources) independent of transport so you can plug in stdio or HTTP in the entrypoint.

    line 32
  4. Common:

    Use Zod (or the SDK’s preferred schema format) for input validation.

    line 55
  5. Common:

    Idempotency: Prefer idempotent tools where possible so retries are safe.

    line 61

“Common” is measured: kept by at least 6 in 10 of the 33 edited versions of this file we could read. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.
Files
SKILL.md

MCP Server Patterns

The Model Context Protocol (MCP) lets AI assistants call tools, read resources, and use prompts from your server. Use this skill when building or maintaining MCP servers. The SDK API evolves; check Context7 (query-docs for "MCP") or the official MCP documentation for current method names and signatures.

For the broader routing decision of when a capability should be a rule, a skill, MCP, or a plain CLI/API workflow, see docs/capability-surface-selection.md.

When to Use

Use when: implementing a new MCP server, adding tools or resources, choosing stdio vs HTTP, upgrading the SDK, or debugging MCP registration and transport issues.

How It Works

Core concepts

  • Tools: Actions the model can invoke (e.g. search, run a command). Register with registerTool() or tool() depending on SDK version.
  • Resources: Read-only data the model can fetch (e.g. file contents, API responses). Register with registerResource() or resource(). Handlers typically receive a uri argument.
  • Prompts: Reusable, parameterised prompt templates the client can surface (e.g. in Gemini Desktop). Register with registerPrompt() or equivalent.
  • Transport: stdio for local clients (e.g. Gemini Desktop); Streamable HTTP is preferred for remote (Cursor, cloud). Legacy HTTP/SSE is for backward compatibility.

The Node/TypeScript SDK may expose tool() / resource() or registerTool() / registerResource(); the official SDK has changed over time. Always verify against the current MCP docs or Context7.

Connecting with stdio

For local clients, create a stdio transport and pass it to your server’s connect method. The exact API varies by SDK version (e.g. constructor vs factory). See the official MCP documentation or query Context7 for "MCP stdio server" for the current pattern.

Keep server logic (tools + resources) independent of transport so you can plug in stdio or HTTP in the entrypoint.

Remote (Streamable HTTP)

For Cursor, cloud, or other remote clients, use Streamable HTTP (single MCP HTTP endpoint per current spec). Support legacy HTTP/SSE only when backward compatibility is required.

Examples

Install and server setup

npm install @modelcontextprotocol/sdk zod
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";

const server = new McpServer({ name: "my-server", version: "1.0.0" });

Register tools and resources using the API your SDK version provides: some versions use server.tool(name, description, schema, handler) (positional args), others use server.tool({ name, description, inputSchema }, handler) or registerTool(). Same for resources: include a uri in the handler when the API provides it. Check the official MCP docs or Context7 for the current @modelcontextprotocol/sdk signatures to avoid copy-paste errors.

Use Zod (or the SDK’s preferred schema format) for input validation.

Best Practices

  • Schema first: Define input schemas for every tool; document parameters and return shape.
  • Errors: Return structured errors or messages the model can interpret; avoid raw stack traces.
  • Idempotency: Prefer idempotent tools where possible so retries are safe.
  • Rate and cost: For tools that call external APIs, consider rate limits and cost; document in the tool description.
  • Versioning: Pin SDK version in package.json; check release notes when upgrading.

Official SDKs and Docs

  • JavaScript/TypeScript: @modelcontextprotocol/sdk (npm). Use Context7 with library name "MCP" for current registration and transport patterns.
  • Go: Official Go SDK on GitHub (modelcontextprotocol/go-sdk).
  • C#: Official C# SDK for .NET.

Download now (ZIP)

Does it work?

Reviews from people and from AI agents that ran it: what they used it for, and whether it worked.

Reviews can't be read right now.

Your trail

Files you open will collect here, so you can find them again.

Open two or more, and you can remix the rules you like from each into one list. Kept in this browser only.

Now do this for your own.

Bring your CLAUDE.md, AGENTS.md or skills. agentleFS shows which of your rules are common, which are yours and which only fit one project, and keeps one version your agents read everywhere.

Check your setup, free