What are the two types of MCP connectors in Claude, and how do I set up a custom one?

There are Claude-promoted (built-in) connectors and custom connectors. Built-in connectors already show up in Claude for things like Slack, Google Drive, a CRM, and other integrated business tools. For anything not already offered, you can build a custom connector: go into the documentation of the company/tool you want to connect, ask Claude to pull the MCP log, and it will prompt you for a name and a remote MCP URL. Many new integrations (e.g., note-taking apps) are expected to release their own MCPs soon, letting you bring notes directly into workflows (e.g., 'bring in my notes from Rebecca and send off the to-do list from the emails'). When starting with a new MCP or API, tools often provide a markdown (MD) file that you can upload to Claude and ask it to learn so it knows what it can and cannot do with that integration.