Context is king. Getting useful results from your AI assistant often hinges on providing the right instructions. Yet most developers take this step casually, then wonder why their AI outputs are mediocre.

You provide context through two channels:

1. Your immediate prompt — the main prompt you type in to the chat¹
2. Master instructions — persistent rules that shape every interaction (this post’s focus)

If you use different tools, you’ll quickly discover the current landscape for how to provide that master context or AI instructions is a mess.

Every AI tool wants its own special instruction file:

• Claude Code: CLAUDE.md
• Cursor: .cursorrules (legacy) and now .cursor/rules
• Windsurf: .windsurfrules
• OpenAI Codex, Gemini CLI, OpenCode: AGENTS.md
• Amp: AGENT.md ²

One file to rule them all

I use all these tools daily: Claude, Cursor, Gemini, OpenAI, Firebender³; and I’m constantly refining my instructions as the AI landscape evolves. Updating the same rules in five different files? That becomes untenable quickly.

So until the big AI companies figure out a common standard, here’s my fix: a single .ai directory with the important instructions and rules in it. But symlinked everywhere so different tools can pick it up.

# Create the master directory
mkdir -p .ai
touch .ai/instructions.md

# Symlink all the different tool configs
ln -s .ai/instructions.md CLAUDE.md
ln -s .ai/instructions.md AGENTS.md       # OpenAI, Gemini CLI, OpenCode
ln -s .ai/instructions.md .cursorrules    # Cursor (project level only)
# ln -s .ai/instructions.md .windsurfrules
# ln -s .ai/instructions.md AGENT.md      # Amp

# Optional: organize related AI assets
mkdir -p .ai/commands    # Custom commands for your project
mkdir -p .ai/rules       # Additional context rules
mkdir -p .ai/plans       # Technical execution steps
mkdir -p .ai/docs        # AI-relevant documentation

# Claude specific setup
mkdir -p .claude
# remember the from directory has to be referenced completely (relative path won't work)
ln -s "/Users/me/.ai/commands" "./.claude/commands"

# Cursor-specific setup
mkdir -p .cursor
ln -s "/Users/me/.ai/rules" "./.cursor/rules"

I centralize my instructions in .ai/instructions.md once, and every tool stays in sync. The main benefit? You edit in one place, and all tools stay synchronized. No more hunting through multiple files when you refine your instructions.

User vs. project level instructions

I keep two levels of instructions:

• User level: ~/.ai/instructions.md — personal preferences that apply across all projects
• Project level: ~/myproject/.ai/instructions.md — shared team instructions specific to a codebase

Is this worth it?

The short answer: yes. While I haven’t done rigorous A/B testing on each rule or instruction, the improvements are noticeable. Without instructions, AI tools default to generic patterns and I’ve found myself having to repeat basic instructions more often. Folks online also seem to agree on this.

Fine-Tuning Your Rules

Want to see what context your AI is actually using? Try asking:

What custom instructions or context files are you currently using for this project?
List any .ai/, AGENTS.md, or tool-specific rule files you can see.

Different tools have varying levels of transparency here. Claude and Cursor are generally forthcoming about loaded context, while others may be more opaque. Use this feedback to refine your instructions, removing redundancy and clarifying ambiguous rules.

The Bottom Line

Until we get a proper standard, this symlink approach keeps things manageable. Edit once, benefit everywhere. It’s not perfect, but it beats copying and pasting the same instructions across a dozen different files every time you want to make a change.

I’ll keep this post updated as new tools emerge and standards (hopefully) converge. In the meantime, may your context be consistent and your tokens be few.