Agent Plugins 1.0: Build Once, Run Across AI Tools On August 6, OpenAI, Amazon, Microsoft, Cursor, and Vercel shipped Agent Plugins 1.0.0, an open standard for packaging AI agent extensions that work across ChatGPT, GitHub Copilot, Cursor, Kiro, VS Code, and Codex without rebuilding for each platform. The format bundles Agent Skills and MCP server configurations in a simple directory, and six clients supported it on launch day. However, the spec defers permissions, sandboxing, and security features to future versions, and an analysis found that 43% of audited MCP servers publish no auditable source code. On August 6, OpenAI, Amazon, Microsoft, Cursor, and Vercel shipped Agent Plugins 1.0.0 — an open, vendor-neutral standard for packaging AI agent extensions that work across ChatGPT, GitHub Copilot, Cursor, Kiro, VS Code, and Codex without rebuilding for each platform. Six clients supported the standard on launch day https://thenextweb.com/news/openai-agent-plugins-open-standard-skills-mcp , which is the kind of immediate multi-platform buy-in that most open standards take years to achieve. The format bundles two components: Agent Skills SKILL.md instruction files that teach agents repeatable tasks and MCP server configurations — packaged together in a simple directory that any compatible client can read. Why AI Tool Builders Were Duplicating Work Before this standard, every AI coding client expected a different folder layout. Developers building the same tool for ChatGPT and Cursor had to maintain two separate packages. Add Copilot and Kiro to the mix and you’re maintaining four. Vercel reportedly originated the Agent Plugins proposal — though the OpenAI-led announcement obscured that — suggesting the fragmentation pain was acute enough for a platform with a smaller developer user base to push the solution forward. The fact that five separate companies co-designed it, rather than OpenAI shipping it alone and hoping others follow, is the strongest signal this solved real shared pain across the ecosystem. Adoption is additive, not breaking. Cursor still ships its own .cursor-plugin/plugin.json alongside the Agent Plugins standard. OpenAI maintains .codex-plugin/plugin.json in parallel. Adding a conformant manifest to an existing plugin expands its reach without abandoning platform-specific behavior — which is why the standard picked up six clients immediately rather than five months later. Related: MCP 2026-07-28 Goes Stateless: What Breaks and How to Migrate A Plugin Is a Directory The format’s defining characteristic is its simplicity. A plugin is a directory. The manifest requires exactly two fields. There is no required CLI tooling, no registry to publish to, and no binary format — the directory is inspectable with standard Unix tools and version-controllable from day one. That readability matters when the spec ships without built-in verification. my-plugin/ ├── plugin.json requires: $schema + name only ├── skills/ │ └── run-tests/ │ └── SKILL.md instructions for the agent └── mcp.json optional MCP server config The minimum plugin.json is two fields: a $schema pointer and a lowercase name under 64 characters. Everything else — version, description, author, license — is optional. Skills live in skills/