Anthropic's LLM coding agent, used in Emiliano's wroclove.rb 2026 MCP demo with a small configuration file pointing Claude at a local MCP server. Given a natural-language request to create an order, Claude picks the MCP tool, calls it, and formats the response (adding currency labels, translating cents into the right units). When the product does not exist, Claude reads the underlying Active Record 'product not found' stack trace and proactively suggests the user double-check the product ID.