September 18, 2026
Project instructions can now be stored in AGENTS.md: Claude Code added support in version 2.1.277
In version 2.1.277 dated 18.09.2026, Claude Code began reading AGENTS.md when a folder has no CLAUDE.md. The built-in agents-md mode, version 0.1.0, is already marked as Built in in the Claude Code source.
Addy Osmani
@addyosmani
Claude Code now supports AGENTS.md. If CLAUDE.md is not specified, we will use it. Hope this helps :)
We're adding support for AGENTS.md to Claude Code. Starting today in version 2.1.277, if there is no CLAUDE.md in a folder, Claude will check for and use AGENTS.md. You can toggle this behavior in /config.
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Previously, Claude Code looked for project instructions in CLAUDE.md. Now the `claude-md-or-agents-md` mode picks up AGENTS.md and `.claude/AGENTS.md` when there is no CLAUDE.md of its own. A separate copy of the instructions in CLAUDE.md is not needed for this mode.
Configuration. The `instructionFiles` setting in `/config` switches between four modes: `claude-md`, `claude-md-or-agents-md`, `claude-md-and-agents-md`, and `managed-only`. The `claude-md-and-agents-md` mode reads AGENTS.md alongside CLAUDE.md and does not load it again if CLAUDE.md already imports or references it.
Nested folders. When reading files within a project, Claude Code picks up nested AGENTS.md files just as it does nested CLAUDE.md files. The mode source limits this search to the project root.
Claude Code documentation as of 18.09.2026 still describes reading only CLAUDE.md. For a shared file, it suggests importing `@AGENTS.md` into CLAUDE.md or using the symlink `ln -s AGENTS.md CLAUDE.md`, then checking via `/context`.
Access. The Free plan does not include access. Claude Code can be connected through API, Bedrock, Agent Platform, or Foundry, but local models are not supported. In an organization, an administrator can set models, MCP lists, versions, and mandatory sign-in.
Installation. The README offers four options:
- macOS/Linux: `curl -fsSL https://claude.ai/install.sh | bash` - Homebrew: `brew install --cask claude-code` - Windows PowerShell: `irm https://claude.ai/install.ps1 | iex` - Windows WinGet: `winget install Anthropic.ClaudeCode`
After installation, run `claude` in the project directory.
Next, a project can choose a shared AGENTS.md or pair it with CLAUDE.md through the `instructionFiles` setting.
