AI agents rely on access to real-time data and APIs are the gateway that enables them to retrieve, interpret, and act on that information. So in the AI era, APIs must do more than support human developers, they now must also be ready for autonomous agents. This paper outlines the 10 most critical enhancements needed to make your APIs machine-consumable, from enriched specs and consistent outputs to natural language metadata and structured error handling. Whether you're modernizing existing APIs or building new ones, these essentials will help ensure your portfolio is discoverable, predictable, secure, and ready to power AI-driven automation across your enterprise.