# MCP in practice

How MCP works, what I learned building and using MCP servers, and how local and remote servers connect, step by step.

A series by dave8172, 2 parts. Page: https://quirkyagents.com/wizard/blog/series/mcp-in-practice/

Two posts from using MCP servers in Claude Code (Upwork's, Notion's and Todoist's) and building one for doceval, my open-source eval tool. Part 1 explains how MCP works and what I learned. Part 2 follows a connection step by step, from starting a local server to signing in to a remote one. Where I tested something, the post says how.

1. [Building and using MCP servers: 4 things I learned](https://quirkyagents.com/wizard/blog/building-mcp-servers-lessons/index.md): How MCP works, one tool call step by step, and four things I learned building and using MCP servers, from tool descriptions to where secrets live.
2. [Local vs remote MCP servers: how each connects, step by step](https://quirkyagents.com/wizard/blog/local-vs-remote-mcp-servers/index.md): How a local MCP server lives and dies with your session, and how remote MCP sign-in works: OAuth, PKCE and tokens, tested on Upwork, Notion and Todoist.