Claude Code Now Reads AGENTS.md When CLAUDE.md Is Missing

Melvin Vivas · X post · 2026-09-19 · Open on X

Topics: AI Dev Tools & Productivity, Prompt & Context Engineering · Level: beginner

Summary

Claude Code added support for AGENTS.md in version 2.1.277. If a folder has no CLAUDE.md, Claude checks for AGENTS.md and uses it instead. You can turn this on or off in /config.

Key points

• Available starting in Claude Code version 2.1.277.
• If a folder has no CLAUDE.md, Claude Code falls back to AGENTS.md.
• Toggle the behavior with /config.
• You can keep one shared AGENTS.md for several coding agents instead of separate files.

Resources mentioned

• Claude Code · tool · code.claude.com · paid · recommended by both Bashiri Smith & Melvin Vivas
  Build agents and pipelines from the terminal; the guide's main agentic coding tool.
  Also in: Create Claude Code Plugins with /plugin-authoring (Melvin Vivas on X · notes), Claude Code mods: customize behavior and UI with plugins (Melvin Vivas on X · notes), AI Engineer Roadmap Overview: From ML Foundations to RAG, Agents & Ops (Bashiri Smith on Facebook · notes), SkillsBento: Free Plugin Marketplace for Codex and Claude Code (Melvin Vivas on X · notes) and 101 more
• AGENTS.md · docs · agents.md · free
  Instruction file format that gives coding agents project context such as the tech stack, skills and MCP servers.
  Also in: Subagents with mixed models: a strong planner and a fast executor (Melvin Vivas on X · notes), Updating Skills and AGENTS.md for Astra with OpenAI's Guidance (Melvin Vivas on X · notes), How to Prompt GPT-6 Astra in Codex: Simpler Instructions, Leaner AGENTS.md (Melvin Vivas on X · notes), OpenAI Guide: Rethinking Skills and Prompts for GPT-6 Astra (Melvin Vivas on X · notes) and 5 more

Try this

• Update Claude Code to 2.1.277 or later and check the AGENTS.md setting in /config.