On August 6, 2026, Amazon, Microsoft, OpenAI, Vercel and Cursor shipped Agent Plugins 1.0.0, an open standard for packaging AI agent skills and MCP servers into portable plugins, already integrated into VS Code, Copilot, Cursor, ChatGPT and Kiro. Google joined as a core maintainer the same day. The launch occurred while the IETF's DAWN working group was still debating agent discovery standards in Vienna, underscoring the industry's preference for shipping over consensus. The standard deliberately excludes distribution mechanisms, provenance verification and permission models, leaving each platform operator to build its own marketplace and security layers. Anthropic, which authored the underlying Agent Skills specification, is notably absent from the coalition. The open packaging format lowers barriers for building agent skills, but the fragmentation in distribution raises questions about whether the agent economy will remain open or devolve into walled gardens sharing a common file format.