An API catalog serves as a crucial substrate for enabling efficient AI-human collaboration within organizations, providing a unified platform that aligns APIs, services, people, and AI agents. As AI agents increasingly participate in development processes, orchestrating workflows, and making autonomous decisions, they can exacerbate existing issues such as fragmented governance, unclear ownership, and versioning problems. A comprehensive API catalog addresses these challenges by centralizing governance, ensuring documentation accuracy, and making APIs discoverable and searchable, ultimately ensuring coherence and reducing chaos. This alignment facilitates faster integration, maintains quality and compliance, and prevents technical debt accumulation by employing governance scorecards to automatically evaluate compliance, quality, and security. The catalog extends beyond APIs to include microservices, data pipelines, and organizational structures, creating a substrate that enhances AI's ability to contribute effectively while empowering humans to focus on business logic. Organizations that establish such a substrate gain a competitive advantage by accelerating time-to-value, automating workflows, and fostering innovation through AI-assisted discovery and integration of APIs.