Claude Co-Commands Plugin

3 collaboration commands for Claude Code that use the Codex MCP server to generate parallel plans, validate plans, and brainstorm ideas.

Commands

| Command | Description | When to Use | |---------|-------------|-------------| | /co-brainstorm | Bounce ideas off Codex | Want fast alternative ideas, critiques, and perspectives | | /co-plan | Generate a parallel plan via Codex | Want a second opinion on your planning approach | | /co-validate | Get a staff engineer review of your plan | Want critical feedback before finalizing a plan |

Prerequisites

Node.js (for npx)
Claude Code

Installation

Option 1: Plugin Marketplace (Recommended)

# Add the marketplace
/plugin marketplace add SnakeO/claude-co-commands
Install the plugin
/plugin install co-commands@snakeo-co-commands

Option 2: Git Clone

git clone https://github.com/SnakeO/claude-co-commands.git
Copy skill folders to ~/.claude/skills/
cp -r claude-co-commands/plugins/co-commands/skills/* ~/.claude/skills/

Option 3: Manual Copy

Copy plugins/co-commands/skills/ contents to ~/.claude/skills/.

MCP Server Setup (Required)

These commands require the Codex MCP server.

Option A: CLI (Recommended)

claude mcp add validate-plans-and-brainstorm-ideas -- npx -y @openai/codex mcp-server

Option B: Manual

Add this to the mcpServers object in ~/.claude.json:

"validate-plans-and-brainstorm-ideas": {
  "command": "npx",
  "args": ["-y", "@openai/codex", "mcp-server"]
}

If you already have entries in mcpServers, merge this as an additional key. Do not overwrite existing servers.

Verify

Restart Claude Code (if you edited ~/.claude.json manually).
Run claude mcp list to confirm the server is registered.
Test with /co-brainstorm test idea and confirm it triggers the MCP call.

Command Details

`/co-brainstorm`

Starts an interactive brainstorming session with Codex. Pass your topic or question as the argument.

/co-brainstorm how should we structure the authentication system

Supports follow-up conversation to dig deeper into ideas.

`/co-plan`

Generates an alternative plan in the background while you continue your own planning. Pass your task description as the argument.

/co-plan add user authentication with OAuth2 support

Compare the Codex plan against yours to catch missed approaches, simpler alternatives, or overlooked edge cases.

`/co-validate`

Sends your plan to Codex for a staff-engineer-style review. Pass the path to your plan file.

/co-validate .claude/plans/my-plan.md

Returns critical issues, simplification opportunities, and alternative approaches. Supports back-and-forth discussion.

Troubleshooting

| Problem | Solution | |---------|----------| | npx: command not found | Install Node.js which includes npm/npx | | MCP tool not found in session | Verify the server name is exactly validate-plans-and-brainstorm-ideas in ~/.claude.json | | JSON parse errors in ~/.claude.json | Validate your JSON (check commas and braces) | | Commands not appearing after install | Restart Claude Code and verify skill folders exist |

License

MIT

--- Tranlated By Open Ai Tx | Last indexed: 2026-05-03 ---