How to Build Mcp Server

An MCP server sits between a model and your actual systems. The model says "I need to publish this draft"; your server exposes a tool called publish_post, accepts the arguments, calls the CMS API, and hands back the result. If you want to learn how an MCP server exposes tools to models in practice, what an MCP server is and how it works walks through the protocol layer in detail.

The parts that trip people up in the docs: authentication lives on your side of the boundary. The client (Claude Desktop, Cursor, whatever) doesn't know your PostPulse API token, and it shouldn't. Your server holds credentials, scopes requests per user, and rotates tokens on a schedule. Standard OAuth flows in the docs gloss over this entirely, so budget an afternoon for it.

Transport choice matters more than it looks. stdio is trivial to run locally but useless once you want a teammate to hit your server from their machine. HTTP+SSE (or streamable HTTP in the newer spec) adds session management and TLS termination, which means you're now running something on a host. For a weekend build I start on stdio, then move to HTTP the moment a second person needs it.

This architecture generalizes. The same pattern that publishes a social post also handles enterprise content generation with AI agents, where the model needs to write, schedule, and report on content across multiple brands without ever holding the underlying API keys.