DBDorian Blancinthe-api-alley.hashnode.dev·Dec 1, 2025 · 8 min readThe Evolution of Service Authorization: Why MCP, OAuth 2.1, and Fine-Grained Authorization Are Now InseparableThe API landscape is undergoing a profound transformation. Six months ago, in June 2025, the Model Context Protocol (MCP) introduced groundbreaking security enhancements that fundamentally changed how AI agents authenticate and interact with external...00