Anthropic adds AGENTS.md spec support to Claude Code; OpenAI contributed AGENTS.md to the Agentic AI Foundation last year
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| Source: Techmeme | Original article
Anthropic has added the AGENTS.md instruction spec to Claude Code, extending OpenAI’s earlier contribution to the Agentic AI Foundation and easing developers’ compatibility woes.
Anthropic announced on Friday that Claude Code now recognises the AGENTS.md instruction specification, a format originally contributed by OpenAI to the Agentic AI Foundation last year. The change means developers can use a single set of markdown‑based rules for AI‑driven coding agents, rather than juggling separate CLAUDE.md and AGENTS.md files for each tool in their stack.
The move matters because AGENTS.md is rapidly becoming the de‑facto standard for describing agent behaviour across platforms such as OpenAI Codex, Cursor and other emerging coding assistants. Until now, teams that mixed Claude Code with non‑Anthropic tools had to maintain parallel instruction files or resort to work‑arounds like symlinks and import directives. By adding native AGENTS.md support, Anthropic eliminates that duplication, streamlines repository configuration and gives developers finer‑grained control over Claude Code’s execution environment.
Anthropic’s release notes for September 2026 list the AGENTS.md update alongside broader stability and UX improvements for Claude Code, including expanded gateway and plugin controls. The company’s documentation still advises importing AGENTS.md into CLAUDE.md with an @AGENTS.md tag or using a symlink, but the new fallback handling reduces friction for mixed‑tool projects.
As we reported on 18 September 2026 in “Claude Code from Source,” the platform has been positioning itself as a versatile coding assistant. The next steps to watch are whether other providers adopt AGENTS.md as a universal convention, how quickly tooling ecosystems adjust their build pipelines, and whether Anthropic extends the spec to cover more advanced agentic features such as dynamic rule loading or cross‑repo sharing. The convergence around a common instruction format could accelerate the maturation of agentic AI development across the Nordic tech scene and beyond.
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