install-codex

ClaudeSkill_CodexHandoff

A personal Claude Code plugin marketplace (claude-skill-codex-handoff).

Plugins

install-codex

Installs the OpenAI Codex CLI (@openai/codex) and the bubblewrap sandbox backend, and exposes an /install-codex skill usable in any session/directory.

The skill also defines a credit-arbitrage delegation workflow: when a code-writing task has a precise input/output spec, Claude asks the user, hands it to Codex running headless (codex exec, write-confined to the working directory), then does a light review. The point is which budget pays — offloading spends your Codex/ChatGPT credits instead of Claude budget — not that Codex is a weaker model (it runs gpt-5.5 at high reasoning).

Prerequisites

• A Codex / ChatGPT subscription (or an OpenAI API key). codex exec will not run without an authenticated account — there is no free tier.
• First-run authentication is interactive and needs a browser. The first time you use the delegation workflow, Codex must be logged in: it runs codex login --device-auth, which prints a one-time code and a https://auth.openai.com/codex/device URL you open in a browser to approve. This is a one-time step per machine/container (tokens live in ~/.codex/); ephemeral web containers re-auth on each fresh start. Installing the CLI itself does not require this — only the headless delegation does.

Setup

This repo is the marketplace root — it lives at the public repo github.com/Mushst/ClaudeSkill_CodexHandoff. Use the commands below.

Use locally (any machine)

claude plugin marketplace add Mushst/ClaudeSkill_CodexHandoff
claude plugin install install-codex@claude-skill-codex-handoff

Then /install-codex is available in every session on that machine.

Persist in Claude Code on the web (fresh containers)

Add these two idempotent lines to your environment setup script (configured in the web UI — see https://code.claude.com/docs/en/claude-code-on-the-web):

claude plugin marketplace add Mushst/ClaudeSkill_CodexHandoff
claude plugin install install-codex@claude-skill-codex-handoff

These re-enable the plugin on every fresh container, across any repo.