Today I learned the hard way that Claude Code (Anthropic's CLI agent) and the Claude chat interface don't have the same access to MCP (Model Context Protocol) servers.
What happened
I was deep in a multi-hour session wiring up my Notion CMS to Gatsby, using Claude Code with the Notion MCP server. Everything was working — search, fetch, schema reads, page creation. Then I hit a wall.
The Claude Code app — the native macOS/terminal agent — doesn't yet have perfect parity with the main chat interface when it comes to remote MCP servers. Some servers that work seamlessly in claude.ai or in Claude's "cowork" mode aren't available (or behave differently) in the CLI tool.
The specifics
- Claude Code connects to MCP servers defined in your local config (
~/.claude/settings.jsonor project-level.claude/settings.json) - Claude chat / cowork has access to a broader set of remote MCP servers that Anthropic manages
- The gap is shrinking — Anthropic is actively adding MCP support — but it's not 1:1 yet
- If you're relying on a specific MCP server, test it in your actual environment before building a workflow around it
The lesson
Don't assume feature parity across Claude's interfaces. The chat UI, the API, and Claude Code are converging but not identical. When planning an agent workflow, prototype in the environment you'll actually run it in.
This is the nature of building with tools that are actively shipping. It's not a bug — it's a snapshot of a fast-moving target.