codex

Installation

$ npx skills add schroneko/skills --skill codex

Summary

Codex CLI (codex exec) を非対話的に呼び出す。実行時に利用可能な最新モデルによるコード実装、レビュー、設計分析に使用する。「codex で実装して」「codex でレビュー」「Codex に聞いて」などのリクエストで使用する。

Agent compatibility

Declared targets from SKILL.md / docs. Unmarked agents are not listed — the skill may still install via the CLI.

Claude Code Declared

Cursor Not declared

Codex Declared

GitHub Copilot Not declared

Windsurf Not declared

Gemini CLI Not declared

Cline Not declared

OpenCode Not declared

Repository health

Stars 1

Default branch main

Open issues 0

Status Active

Package contents

Files included with this skill beyond the listing page.

skill md SKILL.md 4,050 B

docs SUMMARY.md 303 B

History

Jul 2, 2026 First seen on skills.sh

Sep 9, 2026 First recorded snapshot · 17 installs

SKILL.md

You invoke OpenAI Codex CLI in headless (non-interactive) mode from within Claude Code using codex exec. Before each invocation, verify the latest model available from the active client or provider and use only that model for code implementation, review, architecture analysis, security checks, and other tasks.

Prerequisites

codex CLI is installed and authenticated (codex login or OPENAIAPIKEY set)
The working directory should be a git repository (or use --skip-git-repo-check)

Modes

Review mode (read-only)

For code review, analysis, second opinions. Codex cannot modify files.

codex exec --sandbox read-only --ephemeral [OPTIONS] "PROMPT"

Implementation mode (workspace-write)

For code generation and implementation. Codex can create and modify files in the workspace.

codex exec --full-auto --ephemeral [OPTIONS] "PROMPT"

--full-auto is equivalent to --sandbox workspace-write with auto-approval of file writes.

Common flags

Flag	Purpose
`--ephemeral`	Do not persist session to disk (always include)
`-m MODEL`	Use the latest model verified at invocation time
`--skip-git-repo-check`	Allow running outside a git repo
`-C DIR`	Set working directory
`-o FILE`	Write final message to a file
`--json`	Output JSON Lines event stream
`--output-schema FILE`	Force structured output with JSON Schema
`-i IMAGE`	Attach image file to the prompt
`-c key=value`	Override config (e.g. `-c modelreasoningeffort="xhigh"`)

Workflow

For implementation

Identify the files/features to implement
Write a detailed prompt with requirements, file paths, and design constraints
Run codex exec --full-auto --ephemeral -C PROJECT_DIR "PROMPT" via Bash (timeout: 300000ms)
Verify the generated files with Read tool
Run tests/linting to validate quality
Report results to the user

For review

Parse the user's request to determine the task type
Run codex exec --sandbox read-only --ephemeral "PROMPT" via Bash (timeout: 120000ms)
Present the result to the user
If the user wants to act on suggestions, implement them

Built-in review command

codex exec review

Reviews the current diff against the base branch without needing a custom prompt.

Implementation prompt tips

Include the full file path where code should be written
Reference existing files that Codex should read for context
Specify the language, framework, and coding style
Include type signatures, interfaces, or examples from the codebase
Be specific about error handling and edge cases
One task per invocation for best results

Important notes

Set timeout to 120000-300000ms for codex exec calls (implementation takes longer)
Progress logs go to stderr, final answer goes to stdout
Token usage is shown at the end of the output
If the user has ChatGPT Plus/Pro, Codex usage is included in the subscription
If using API key, each call consumes OpenAI API credits
--dangerously-bypass-approvals-and-sandbox はサンドボックスを無効化し、ファイルシステム全体への書き込みを許可するため使わない
Codex requires a git repo by default; add --skip-git-repo-check for non-repo directories