What Is an MCP Server?
MCP (Model Context Protocol) is an open standard developed by Anthropic that allows AI agents like Claude and Cursor to call external tools, APIs, and data sources in a structured way.
An MCP server is a service that exposes a set of "tools" — functions that an AI agent can call to take actions or retrieve data. Instead of the AI agent needing to know how to make HTTP requests directly, it asks the MCP server to call a tool on its behalf.
How Does an MCP Server Work?
When you connect an MCP server to Claude Desktop, Claude gains the ability to:
- Read data from your API (e.g., list customers, fetch orders)
- Write data through your API (e.g., create invoices, update records)
- Take actions (e.g., send emails, trigger workflows)
The AI agent communicates with the MCP server using JSON-RPC over HTTP or SSE (Server-Sent Events). The server responds with the results of each tool call.
Why Do MCP Servers Matter?
Before MCP, connecting Claude to an external API required custom code for every integration. MCP standardizes this — any MCP-compatible AI client can use any MCP server without custom glue code.
This means you can:
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- Give Cursor access to your database or CRM
- Let AI agents take actions in your SaaS product
MCP Servers in Production
Running MCP servers in production introduces important questions:
- **Which endpoints should the AI agent access?** Not every API endpoint should be exposed. Delete operations, billing endpoints, and admin functions need to be controlled carefully.
- **How are credentials managed?** API keys should never be stored on the client side where Claude runs.
- **What did the agent do?** Audit logs are essential for traceability.
MCPForge addresses all of these challenges by providing hosted MCP infrastructure with built-in permissions, credentials management, approval workflows, and audit logs.
Getting Started
The fastest way to create an MCP server from an existing API is to use an OpenAPI spec (also known as a Swagger spec). Most modern APIs expose one at `/openapi.json` or `/swagger.json`.
With MCPForge, you can paste your OpenAPI spec URL and get a hosted MCP server in under 60 seconds — with high-risk endpoints automatically detected and blocked by default.