What is an MCP server?
An MCP server gives Claude tools for an outside system through the Model Context Protocol, for example a database, a browser, GitHub or a design tool. Some run on your machine; others are cloud services that receive your data.
How do I add a local MCP server?
Find the launch command in the server's README (often npx, uvx or docker), then run claude mcp add server-name -- the-command. Pass any API keys the README asks for as environment variables.
How do I add a remote MCP server?
Use the HTTP transport with the server's URL: claude mcp add --transport http server-name https://example.com/mcp.
How do I check it worked?
Run claude mcp list to see your servers and whether they connected. Before adding one, check its MCPMods page: it shows whether your data leaves your machine, whether it needs credentials and whether it can take actions such as sending or deleting.