[Editorial] Claude Code reads AGENTS.md: the story is agent-instruction convergence, not one fewer file

Why it matters

Our take: Anthropic engineer Thariq (@trq212) said Claude Code 2.1.277 falls back to AGENTS.md when CLAUDE.md is missing—a small compatibility patch that signals a bigger shift toward one shared project playbook across coding agents. Cursor/Codex/Cline/Windsurf already leaned on AGENTS.md; Claude Code’s CLAUDE.md-only habit forced dual files or brittle symlinks. The toggle lives in /config and reportedly isn’t on Bedrock/Vertex/Foundry yet—convergence is incomplete, but the direction is clear: competition is moving from model quality alone to whether tools honor the same repo contract. Editorial synthesis of public posts, not a press release.