I've been working a lot with AI coding tools lately—Claude Code, GitHub Copilot Chat, Cursor, Replit’s agent, v0, you name it.
And here's the thing no one seems to be talking about:
Every single one uses a different format for configuring how the agent behaves.
Cursor wants .cursorrules (or now .cursor/rules/*.mdc). Claude has CLAUDE.md, .claude/settings.json, and a whole command system. GitHub Copilot uses copilot-instructions.md. VS Code has .chatmode.md. Some tools want YAML frontmatter, others need Markdown sections, some are just XML pretending to be Markdown.
Even new formats like AGENT.md and llms.txt are cropping up. Meanwhile, you’re never quite sure if your configuration is even being used or silently ignored.
The result?
You're juggling 5+ config syntaxes across tools that don't talk to each other, can't share rules, and often bury the docs three links deep.
I got so frustrated trying to make sense of it all that I started keeping notes and eventually wrote a longform breakdown of what each system does, where the overlaps are, and whether there’s any hope of standardization.
.cursorrules.mdc.chatmode.mdCLAUDE.mdcopilot-instructions.mdllms.txtAGENT.md- …and on and on
🔗 Here’s the deep dive if you’re interested
Would love to hear how others are managing this. Is your team standardizing on anything? Are you writing converters? Or just copying and pasting the same prompt to five tools?
Let's talk. Because this is getting… out of hand.
Top comments (1)
Curious if others are running into the same thing — every tool seems to have its own weird rule file now. Anyone found a format that actually works well for them?