# What Functionalities Does the Codex Plugin Offer? Core Commands and Architecture Explained > Explore the Codex plugin functionalities and core commands. Discover how it streamlines code reviews, task delegation, and more with its architecture. - Repository: [OpenAI/codex-plugin-cc](https://github.com/openai/codex-plugin-cc) - Tags: deep-dive - Published: 2026-07-03 --- **The Codex plugin for Claude Code provides eight slash commands that enable read-only code reviews, adversarial analysis, task delegation, session transfer, and background job management by wrapping the local Codex CLI in a thin client-side adapter.** The openai/codex-plugin-cc repository delivers a client-side integration layer that connects Claude Code directly to the local Codex binary. This plugin transforms Claude Code into a control center for OpenAI's Codex CLI, allowing developers to invoke AI-powered code analysis and automated task execution without leaving their editor or relying on external services. ## Core Slash Commands The plugin exposes a comprehensive command set through markdown definitions stored in `plugins/codex/commands/`. Each command maps to a specific sub-command implemented in the central dispatcher script. ### Read-Only Code Review The `/codex:review` command executes a **read-only** analysis of your repository. According to the source code in [`plugins/codex/commands/review.md`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/commands/review.md), this command can evaluate uncommitted changes, branch diffs, or custom scopes. The implementation delegates to `scripts/codex-companion.mjs`, which invokes the `review` sub-command and respects the user's existing Codex configuration in `~/.codex/config.toml` or project-level [`.codex/config.toml`](https://github.com/openai/codex-plugin-cc/blob/main/.codex/config.toml). ### Adversarial Review For steerable analysis, `/codex:adversarial-review` accepts extra focus text that challenges design decisions and identifies risk areas. Defined in [`plugins/codex/commands/adversarial-review.md`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/commands/adversarial-review.md), this command triggers the `adversarial-review` branch of `codex-companion.mjs`, allowing you to supply custom prompts such as "look for race conditions and question the chosen approach." ### Task Delegation and Rescue The `/codex:rescue` command hands concrete tasks to Codex via the `codex-rescue` sub-agent. As specified in [`plugins/codex/commands/rescue.md`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/commands/rescue.md), this supports bug investigation, fixing failing tests, and code generation. The heavy lifting occurs in the `task` mode of `codex-companion.mjs`, which can run in background mode while you continue working. ### Session Transfer `/codex:transfer` exports the current Claude Code session as a Codex-compatible thread. The implementation in [`plugins/codex/commands/transfer.md`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/commands/transfer.md) calls the `transfer` sub-command, which uses `lib/claude-session-transfer.mjs` to locate the Claude transcript file and invoke Codex's `importExternalAgentSession` function. This generates a session ID you can resume with `codex resume `. ### Job Management The plugin provides three commands for managing background operations: - **`/codex:status`** – Displays the state of all background Codex jobs (running, completed, or failed) by reading from the job store in `lib/state.mjs`. - **`/codex:result`** – Retrieves final output from finished jobs, including the session ID needed to reopen discussions in the Codex app. - **`/codex:cancel`** – Terminates running background jobs by interacting with the process management layer in `lib/job-control.mjs`. ### Setup and Configuration The `/codex:setup` command verifies that the Codex binary is installed and that the user is authenticated. This command, defined in [`plugins/codex/commands/setup.md`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/commands/setup.md), uses the `buildSetupReport` helper in `codex-companion.mjs` to generate a status report. ### Review Gate When enabled via `/codex:setup --enable-review-gate`, this functionality forces a targeted Codex review after every Claude turn. The stop-hook defined in `plugins/codex/scripts/stop-review-gate-hook.mjs` consults the plugin's state (`state.mjs`) and blocks Claude's continuation if the review finds issues, requiring user acknowledgment before proceeding. ## Architecture and Implementation The plugin's architecture follows a clean separation between command definitions, dispatch logic, and state management. ### Command Discovery and Dispatch Each slash command is described in a Markdown file under `plugins/codex/commands/`. The Claude Code runtime parses these files to expose commands to the user. All commands delegate to `scripts/codex-companion.mjs`, a Node.js entry point that parses arguments via `lib/args.mjs`, resolves the workspace through `lib/workspace.mjs`, and routes to the appropriate operation handler. ### Job Management and State Background tasks are tracked via a lightweight JSON-based job store implemented in `lib/state.mjs` and `lib/job-control.mjs`. Each job receives a UUID, with progress logs written to `state/` files. The `status` and `result` commands read from this persistent store, enabling you to check on long-running reviews or rescue operations hours after initiating them. ### Codex CLI Integration The companion script invokes the local Codex CLI through functions like `binaryAvailable`, `runAppServerReview`, and `runAppServerTurn`. Because the plugin executes the same binary available in your `$PATH`, it automatically respects your existing Codex configuration and authentication state without requiring additional API keys or external service credentials. ### Session Transfer Mechanics Session export functionality relies on `lib/claude-session-transfer.mjs` to locate the Claude transcript file, then calls Codex's external-agent importer. This creates a persistent Codex thread that maintains conversation context, allowing seamless handoff from Claude Code's iterative editing environment to Codex's specialized UI for extended discussions. ## How to Use the Codex Plugin After installing the plugin (`/plugin install codex@openai-codex`) and ensuring the Codex CLI is available (`npm install -g @openai/codex`), you can invoke these commands directly in Claude Code: ```bash # Run a foreground review of uncommitted changes /codex:review # Run a review in the background (recommended for large changes) /codex:review --background # Review a specific branch comparison /codex:review --base main # Execute an adversarial review with custom focus /codex:adversarial-review --background look for race conditions and question the chosen approach # Delegate a bug fix to Codex /codex:rescue --background fix the failing test with the smallest safe patch # Resume a previous rescue job /codex:rescue --resume # Transfer current session to Codex /codex:transfer # Check background job status /codex:status /codex:status # Retrieve finished job results /codex:result /codex:result # Cancel a running job /codex:cancel # Verify installation and enable review gate /codex:setup --enable-review-gate ``` ## Summary - **The Codex plugin** provides eight slash commands (`review`, `adversarial-review`, `rescue`, `transfer`, `status`, `result`, `cancel`, `setup`) that bridge Claude Code and the local Codex CLI. - **Command definitions** live in `plugins/codex/commands/*.md` and dispatch through `scripts/codex-companion.mjs`. - **Background job management** uses `lib/state.mjs` and `lib/job-control.mjs` to track UUID-based tasks with persistent logging. - **Session transfer** allows exporting Claude conversations to Codex via `lib/claude-session-transfer.mjs` and the `importExternalAgentSession` function. - **The review gate** optionally enforces Codex reviews before Claude can proceed, implemented via `stop-review-gate-hook.mjs`. ## Frequently Asked Questions ### What do I need to install before using the Codex plugin? You must install the Codex CLI globally (`npm install -g @openai/codex`) and verify it is in your system PATH. The `/codex:setup` command checks for the binary and authentication status, reporting any missing dependencies before you attempt to run reviews or tasks. ### How does the review gate functionality work? When enabled via `/codex:setup --enable-review-gate`, the plugin installs a stop-hook that triggers after every Claude turn. The hook invokes `stop-review-gate-hook.mjs`, which runs a targeted Codex review and checks the output against [`schemas/review-output.schema.json`](https://github.com/openai/codex-plugin-cc/blob/main/schemas/review-output.schema.json). If the review identifies issues, Claude blocks further execution until you acknowledge the findings, effectively forcing a code review checkpoint in your workflow. ### Can I run multiple Codex reviews simultaneously? Yes. By appending the `--background` flag to `/codex:review` or `/codex:rescue`, you delegate the operation to a background process managed by `lib/job-control.mjs`. Use `/codex:status` to monitor all active jobs and `/codex:result` to retrieve outputs when they complete, allowing you to queue multiple analyses while continuing to edit code. ### How do I continue a conversation in Codex after starting it in Claude Code? Use `/codex:transfer` to export your current Claude session. This command invokes `codex-companion.mjs` with the `transfer` sub-command, which uses `lib/claude-session-transfer.mjs` to package your transcript and call Codex's `importExternalAgentSession`. The command outputs a session ID that you can use with `codex resume ` to continue the discussion in the native Codex application.