agentrc

One config file for all your AI coding agents.

Write your AI instructions once. Claude Code, Gemini, Codex, Copilot — they all get them.

The problem

You use multiple AI coding agents. Each reads instructions from a different file:

Agent	Reads from
Claude Code	~/.claude/CLAUDE.md
Gemini CLI	~/.gemini/GEMINI.md
Codex CLI	~/.codex/AGENTS.md
GitHub Copilot	~/.copilot/copilot-instructions.md

When you add a rule to CLAUDE.md ("fix root causes, not symptoms"), your other agents don't know about it. You end up maintaining 4 files that drift apart.

The solution

Maintain one file. Run agentrc. All agents get the same instructions.

~/.claude/CLAUDE.md  (you edit this)
        |
        v  agentrc
        |
        +---> ~/.gemini/GEMINI.md
        +---> ~/.codex/AGENTS.md
        +---> ~/.copilot/copilot-instructions.md
        +---> ~/AGENTS.md (cross-tool fallback)

Install

# Download
curl -fsSL https://raw.githubusercontent.com/bkrisetya/agentrc/main/agentrc.sh \
  -o ~/.local/bin/agentrc
chmod +x ~/.local/bin/agentrc

# Or clone
git clone https://github.com/bkrisetya/agentrc.git
cp agentrc/agentrc.sh ~/.local/bin/agentrc

Usage

# Sync from default source (~/.claude/CLAUDE.md)
agentrc

# Sync from a custom source file
agentrc ~/my-instructions.md

# See what's current vs stale
agentrc --list

# Preview without writing
agentrc --dry-run

Output

agentrc v0.1.0 — syncing from /home/you/.claude/CLAUDE.md
  [ok] /home/you/.gemini/GEMINI.md
  [ok] /home/you/.codex/AGENTS.md
  [ok] /home/you/.copilot/copilot-instructions.md
  [ok] /home/you/AGENTS.md

Done. Wrote 4 targets.

Automate it

Claude Code hook (runs after every session)

Add to ~/.claude/settings.json:

{
  "hooks": {
    "Stop": [
      { "command": "agentrc --quiet" }
    ]
  }
}

Cron (every 15 minutes)

*/15 * * * * ~/.local/bin/agentrc --quiet

Git hook (post-commit)

echo '#!/bin/sh
agentrc --quiet' > .git/hooks/post-commit
chmod +x .git/hooks/post-commit

Custom targets

Add extra target paths to ~/.config/agentrc/targets.conf:

# One path per line
~/.cursor/rules/instructions.md
~/.aider/conventions.md
~/.continue/config.md

Custom source

Set AGENTRC_SOURCE to use a different source file:

export AGENTRC_SOURCE=~/my-ai-rules.md
agentrc

How it works

1. Reads your source file (default: ~/.claude/CLAUDE.md)
2. For each target agent, writes the source content with a small header comment
3. Handles Windows (OneDrive path redirect, Git Bash compatibility)
4. Skips targets where the directory can't be created (no errors, just [skip])

The script is 200 lines of bash with zero dependencies. It works on Linux, macOS, and Windows (Git Bash).

FAQ

Q: Does it modify my source file? No. It only reads the source and writes to target locations.

Q: What if I don't use all these agents? It only writes to directories that exist or can be created. Missing agents are silently skipped.

Q: Does it work on Windows? Yes, via Git Bash. It handles the USERPROFILE / OneDrive path redirect that Windows users encounter.

Q: Can I use something other than CLAUDE.md as the source? Yes. Pass any markdown file as an argument, or set AGENTRC_SOURCE.

Q: What about agent-specific instructions? Use your source file for shared rules. For agent-specific overrides, edit the target files directly — agentrc will overwrite them on next run, so keep agent-specific rules in a separate section of your source file.

Caveats

• Overwrites target files. Each run replaces the target files entirely. If you've manually edited ~/.gemini/GEMINI.md, those edits are lost on the next agentrc run. Keep all instructions in your source file.
• Not all instructions are portable. Your CLAUDE.md may reference Claude Code-specific features (tools like Read, Edit, Glob; skills; plan mode; subagents). Other agents will see these instructions but may not understand them. This is usually harmless — agents ignore what they don't support.
• Agent path conventions may change. The target paths (~/.gemini/GEMINI.md, ~/.codex/AGENTS.md, etc.) are based on current agent CLI versions as of early 2026. If an agent changes where it reads instructions, you may need to update targets.conf.
• Requires bash 4+ for associative arrays. macOS ships bash 3 but most users have bash 4+ via Homebrew. The script will error clearly if bash is too old.
• No merge, just overwrite. This is a fan-out tool, not a sync tool. It does not merge agent-specific changes back into your source. The source file is the single source of truth.

License

MIT