Downloadable computer software for publishing, browsing, licensing, and deploying AI-based agents and reusable AI skill packages via an online marketplace, and for integrating such agents into third-party agent client applications, in the field of AI agent marketplaces; Downloadable computer programs using artificial intelligence (AI) for packaging human expertise into reusable AI skill packages and for executing such packages as finished AI agents, in the field of AI agent development and AI agent marketplaces; Downloadable application programming interface (API) software for integrating AI-based agents and reusable AI skill packages from an online marketplace into third-party agent client applications and developer tools; Electronic database in the field of AI-based agents, reusable AI skill packages, publisher profiles, agent ratings and reviews, and license usage data, recorded on computer media; Downloadable electronic data files featuring reusable AI skill packages, AI agent configuration data, AI agent prompt templates, and AI agent metadata for use within an AI agent marketplace; Electronic software updates, namely, downloadable computer software and associated downloadable data files for updating computer software in the fields of AI agent marketplaces, AI skill packages, and conversational AI applications,, provided via computer and communication networks; Downloadable computer software for computer system and application development, deployment and management; Downloadable computer software development tools; Downloadable software development kits (SDK); Downloadable application programming interface (API) software; Downloadable computer software for use as an application programming interface (API); Downloadable software using artificial intelligence for simulating natural conversation