Skip to main content Skills Marketplace Discover and explore AI skills built by the community.
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
Show prompt details A direct command skips the review prompt. Inspect the source before running it.
npx skills add https://github.com/microsoft/copilot-sdk-samples --skill mcp-builderThe command stays on one line. Scroll horizontally to inspect it before copying.
Prefer a local copy? Download the files currently available to SkillsMP.
Download Zip Downloading... More from this repository Related occupations SOC
Based on SOC occupation classification
name mcp-builder description Build MCP (Model Context Protocol) clients to connect AI agents with external tools and data sources. Use when building integrations with MCP servers. license MIT compatibility Requires TypeScript, Node.js 18+ metadata {"author":"copilot-sdk-samples","version":"1.0"}
MCP Builder Skill
Build MCP (Model Context Protocol) clients that connect AI agents with external tools and data sources.
When to Use This Skill
Use this skill when:
Building a client to connect to an MCP server
Integrating AI agents with external data sources via MCP
Creating typed wrappers around MCP tool calls
The user mentions "MCP", "Model Context Protocol", or needs to connect to an MCP endpoint
MCP Protocol Overview
MCP is an open protocol for connecting AI models to external tools and data. Key concepts:
MCP Server : Exposes tools, resources, and prompts via JSON-RPC over HTTP (streamable) or stdioMCP Client : Connects to servers, discovers tools, and executes tool callsTools : Functions the model can invoke (e.g., search_docs,
fetch_page
Resources : Data the model can read (e.g., docs://azure/overview)
Implementation Pattern Follow this pattern when building MCP clients:
1. Define the Interface export interface MCPClientConfig {
mode : "mock" | "live" ;
endpoint ?: string ;
}
export interface MyMCPClient {
readonly mode : "mock" | "live" ;
readonly isInitialized : boolean ;
initialize (): Promise <ConnectorResult <void >>;
dispose (): Promise <void >;
toolName (args : ToolArgs ): Promise <ConnectorResult <ToolResult >>;
}
2. Implement Mock Client First Always create a mock implementation that works without network calls:
class MockMyMCPClient implements MyMCPClient {
readonly mode = "mock" as const ;
private _isInitialized = false ;
get isInitialized (): boolean {
return this ._isInitialized ;
}
async initialize (): Promise <ConnectorResult <void >> {
this ._isInitialized = true ;
return success (undefined );
}
async dispose (): Promise <void > {
this ._isInitialized = false ;
}
async toolName (args : ToolArgs ): Promise <ConnectorResult <ToolResult >> {
if (!this ._isInitialized ) {
return failure ({
code : ErrorCodes .NOT_INITIALIZED ,
message : "Client not initialized" ,
});
}
return success ({
});
}
}
3. Use ConnectorResult Pattern All methods must return ConnectorResult<T>:
import {
ConnectorResult ,
success,
failure,
ErrorCodes ,
} from "../shared/connectors/types.js" ;
return success (data);
return failure ({
code : ErrorCodes .NOT_FOUND ,
message : "Resource not found" ,
});
4. Factory Function Export a factory function:
export function createMyMCPClient (config : MCPClientConfig MyMCPClient {
if (config.mode === "mock" ) {
return new MockMyMCPClient (config);
}
return new LiveMyMCPClient (config);
}
Example: Microsoft Learn MCP Server The Microsoft Learn MCP Server (https://learn.microsoft.com/api/mcp) provides:
Tools
microsoft_docs_search - Search Microsoft Learn documentationmicrosoft_docs_fetch - Fetch and convert a page to markdownmicrosoft_code_sample_search - Search code samples
Client Implementation export interface DocSearchResult {
title : string ;
url : string ;
snippet : string ;
}
export interface MSLearnMCPClient {
readonly mode : "mock" | "live" ;
readonly isInitialized : boolean ;
initialize (): Promise <ConnectorResult <void >>;
dispose (): Promise <void >;
searchDocs (query : string ): Promise <ConnectorResult <DocSearchResult []>>;
fetchDoc (url : string ): Promise <ConnectorResult <string >>;
searchCodeSamples (
query : string ,
language ?: string ,
): Promise <ConnectorResult <CodeSampleResult []>>;
}
Testing Requirements Every MCP client must include:
Unit tests using Vitest
Tests for initialization/disposal
Tests for each tool method
Tests for error handling (NOT_INITIALIZED, etc.)
describe ("MyMCPClient" , () => {
let client : MyMCPClient ;
beforeEach (async () => {
client = createMyMCPClient ({ mode : "mock" });
await client.initialize ();
});
afterEach (async () => {
await client.dispose ();
});
it ("should initialize successfully" , () => {
expect (client.isInitialized ).toBe (true );
});
it ("should fail when not initialized" , async () => {
const uninit = createMyMCPClient ({ mode : "mock" });
const result = await uninit.toolName ({});
expect (result.success ).toBe (false );
expect (result.error ?.code ).toBe ("NOT_INITIALIZED" );
});
});
File Structure shared/connectors/<name>/
├── client.ts # Client implementation
└── index.ts # Public exports
test/connectors/
└── <name>.test.ts
Acceptance Criteria A valid MCP client implementation must:
✅ Export a factory function create<Name>Client(config)
✅ Support both mock and live modes
✅ Use ConnectorResult<T> for all async operations
✅ Have isInitialized property
✅ Return NOT_INITIALIZED error when called before initialize()
✅ Include comprehensive unit tests
✅ Follow existing connector patterns in the codebase
