Agent Plugins - one package format for skills and MCP servers
Canonical version: Agent Plugins - one package format for skills and MCP servers.
A new open specification landed: Agent Plugins 1.0, with an initial technical steering committee made of Amazon, Cursor, Microsoft, OpenAI and Vercel. It defines a portable package format for extending agents, so an extension is authored once instead of being repackaged per client.
The format is deliberately small. A plugin is a directory with a plugin.json manifest at its root. Two component types are standardized: AI Agent Skills discovered from a skills/ folder (each with its own SKILL.md, following the Agent Skills spec), and Model Context Protocol (MCP) servers declared in mcp.json, over stdio, Streamable HTTP, or the legacy HTTP+SSE transport. Anything client-specific goes under a reverse-domain extensions namespace, which keeps the shared surface honest.
What the spec explicitly does not cover: distribution, installation, permissions, and UX. Those stay with each client. It is an interoperability floor, not a package manager.
Adoption is already broad for a working draft. GitHub Copilot shipped support in VS Code, the Copilot CLI and the Copilot app; ChatGPT, OpenAI Codex, Hermes Agent, OpenClaw, Cursor and Grok are on the list too.
This is one more entrant in a crowded space, next to Microsoft's own APM (AI) and a handful of other manifests. Which one wins is not settled, and the overlap is real. But the direction is right: the value of a skill or an MCP server should not depend on which agent you happen to run. Every hour spent porting the same extension to five clients is an hour not spent on the extension.
References
- Specification: https://agent-plugins.org/specification
- Site: https://agent-plugins.org/
- Repository: https://github.com/agentplugins/agent-plugins-spec
- GitHub Copilot changelog: https://github.blog/changelog/2026-08-12-agent-plugins-1-0-in-vs-code-copilot-cli-and-the-copilot-app/
- Discussion on overlap with other formats: https://github.com/agentplugins/agent-plugins-spec/discussions/36
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