The AI giants have joined forces to ask the world’s developers to all please write their agentic skills and tools into the same format. In return, coders will be able to move these superpowers easily from one platform to another (such as when they get laid off). It's designed to be write once, run everywhere.

Vercel posted the initial draft of the Agent Plugins spec on Thursday, with input from Amazon, Cursor, Microsoft, and OpenAI, which all pledged fidelity (and engineers) to the project. It was quickly embraced by the Linux Foundation’s Agentic AI Foundation (AAIF), though it will operate as an independent entity.

Agent Plugins 1.0 packages an AI agent’s skills and tools in a single directory structure. It builds on the AAIF-stewarded MCP protocol and the open Agent Skills standard originally created by Anthropic in 2025.

Agent Skills holds the instructions for how the agent should perform a specific task. MCP provides the connectivity to outside databases, APIs, shell scripts, and other external resources. Together, the trio makes AI capabilities modular so that they are, in theory, write-once-run-anywhere. 

It is still up to the agent clients, or platforms, to provide a user interface, establish security boundaries and create marketplaces where the plugins can be shared. Thus far, VS Code, Cursor, GitHub Copilot, ChatGPT, Codex, and Kiro all support the standard.

File-system-as-configuration

Agent Plugins follows the Next.js practice of using the host computer’s directory format as the structure for defining components.

The spec prescribes creating a top-level directory for each plug-in, with a small manifest and schema. The manifest provides the name, version and schema of the plugin in JSON format. Skills are filed in the skills sub-directory, and the MCP server configuration is stored as an mcp.json file.  

Those are the essential elements, though the plugin authors can also use the namespace directory to store additional extensions. This format “keeps the shared format predictable without requiring it to absorb every client-specific experiment happening across agent products,” noted the AAIF in a blog post. 

Bundling the skills with the MCP configuration makes the package portable, allowing it to be copied and used across any supporting agent client.

The narrow way

Agent developers around the globe are adding all manner of experimental hooks, rules and extensions into their skills. Nonetheless, the keepers of the spec deliberately kept the scope “narrow” for this 1.0 release, in AAIF’s words. The best ones may be considered for future versions of the spec, though the team is not making any promises. Until then, developers can add all these extensions to the namespace and hope for the best, portability-wise.  

Going forward, Agent Plugins will be managed under an open governance model, with an independent technical oversight committee calling the shots, considering input from the public. Currently, engineers from Amazon, Cursor, Microsoft, OpenAI, and Vercel are on the core development team. The spec is licensed under the Creative Commons Attribution 4.0 International License (CC-BY-4.0).

There are other efforts underway to tame the wild frontier of agent development. Google folded its own Agent2Agent (A2A) agentic communications protocol effort into AAIF. Google is also building out a specification for finding tools on the web, called Agentic Resource Discovery.

AAIF has a similar “complementary” project to Agent Plugins, Skills Over MCP, which shares skills by bundling them into the MCP server itself. Essentially, this approach is akin to shipping “the manual with the product,” wrote AAIF Vice President Angie Jones. 

Should MCPs be festooned with skills? Or should each set of skills come with an attached MCP? Let the best approach win! ®