Anthropic updated its terminal-based coding tool to recognize a common industry file for project configurations. The software now checks for AGENTS.md if a CLAUDE.md file is not present in a folder, reducing the need for developers to create multiple redundant instruction sets for different AI agents. Users can enable or disable this fallback behavior through the /config command.

This support is integrated via "Claude Code mods," a new framework for customizing the tool's harness that enables custom project instructions. Released in version 2.1.277, the feature reflects a shift toward a shared ecosystem where different coding AI agents can collaborate on the same repositories. The update allows developers to stop using placeholder files to link multiple tools to a single set of project instructions.