OpenAI Codex CLI¶

OpenAI Codex CLI is OpenAI's command-line coding assistant.

Plugin Structure¶

my-plugin/
├── agents.yaml          # Agent definitions (optional)
└── commands/            # Slash commands
    └── build.md

Commands¶

Commands are Markdown files with YAML frontmatter:

---
name: build
description: Build the project
---

Build the project using the appropriate build system.
Detect the project type and run the correct command.

Agents (Optional)¶

If you need agent-like behavior, define in agents.yaml:

agents:
  - name: code-reviewer
    description: Reviews code for quality
    instructions: |
      You review code for best practices...

Installation¶

Copy your plugin to the Codex plugins directory:

cp -r my-plugin ~/.codex/plugins/

Available Tools¶

Tool	Description
read	Read file contents
write	Write files
shell	Execute shell commands
search	Search files

MCP Server Configuration¶

Codex CLI supports MCP servers in configuration:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@anthropic-ai/mcp-server-filesystem"]
    }
  }
}

Converting from Canonical¶

import (
    "github.com/agentplexus/assistantkit/commands/core"
    "github.com/agentplexus/assistantkit/commands/codex"
)

canonical := core.Command{
    Name:        "build",
    Description: "Build the project",
    Prompt:      "Build the project...",
}

codexCmd := codex.FromCanonical(canonical)

Limitations¶

No Skills: Codex CLI does not have a dedicated skills system
Limited Agent Support: Basic agent configuration only
Simpler Structure: Fewer configuration options than Claude Code

Tool Mapping¶

Canonical	Codex
Read	read
Write	write
Edit	edit
Bash	shell
Glob	search
Grep	search