A skill that integrates OpenAI Codex as an MCP server for plan review, code review, and completion verification.

This repository is a Claude Code plugin marketplace containing an agentskills.io compatible skill. The installation instructions below are for Claude Code, but the skill can be adapted for other compatible agents.

For background on why this exists, see Combining Claude and Codex.

The codex-review skill teaches an agent to:

• Review plans before implementation
• Verify completion after implementation, especially after context compactions
• Review code after writing significant changes
• Iterate on feedback until Codex approves

• Claude Code installed
• Codex CLI installed

Add this repository as a marketplace and install the plugin:

/plugin marketplace add tvishwanadha/codex-skills
/plugin install codex-review

The plugin automatically configures the Codex MCP server.

Add the following to ~/.claude/CLAUDE.md:

# User-Level Instructions

## Using Codex for Review

**You MUST invoke the `codex-review` skill:**
- Before exiting plan mode for multi-file changes or architectural decisions
- Before telling the user work is complete after long tasks or context compactions
- After writing significant code changes

Skip only for: simple docs, single-file changes, trivial fixes.

Add to ~/.claude/settings.json:

{
  "permissions": {
    "allow": ["mcp__plugin_codex-review_codex__*"]
  }
}

The plugin bundles an MCP server configuration that runs codex mcp-server. When installed, Claude Code namespaces the server as plugin:codex-review:codex, which determines the tool names:

• mcp__plugin_codex-review_codex__codex - Start a thread
• mcp__plugin_codex-review_codex__codex-reply - Continue a thread

The skill uses semantic tool references (e.g., "Codex MCP server's codex tool") rather than Claude Code-specific names, making SKILL.md portable across agents that support the agentskills.io format.

The SKILL.md frontmatter includes license and compatibility fields per the agentskills.io spec.

See SKILL.md for the full skill reference including:

• Constraints and limitations
• When to use (and skip)
• Thread configuration (approval-policy, sandbox)
• Workflow templates for plan review, completion verification, and code review
• Thread management