# How the Codex Plugin Review Gate Works and When to Enable It

> Understand the Codex plugin review gate's code checks and when to enable it for sensitive projects. Secure your codebase with this essential protocol.

- Repository: [OpenAI/codex-plugin-cc](https://github.com/openai/codex-plugin-cc)
- Tags: how-to-guide
- Published: 2026-08-02

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**The Codex plugin review gate is a protocol-based checkpoint that intercepts generated code before delivery, running linting, security, and policy checks that must pass before the snippet reaches the user; enable it via the `CODIX_REVIEW_GATE` environment variable or `reviewGate: true` in [`config.json`](https://github.com/openai/codex-plugin-cc/blob/main/config.json) when working with sensitive codebases or regulated environments.**

The Codex plugin review gate in the `openai/codex-plugin-cc` repository controls whether generated code reaches the user or file system. It acts as a mandatory checkpoint within the App‑Server protocol, verifying snippets against organizational standards before approval. Understanding when and how to enable this gate ensures you balance security compliance with development velocity.

## What Is the Codex Plugin Review Gate?

The review gate is an internal protocol mechanism defined in [`plugins/codex/scripts/lib/app-server-protocol.d.ts`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/scripts/lib/app-server-protocol.d.ts). It intercepts every generation pass between the back‑end Codex engine and the front‑end UI, creating a synchronous checkpoint where code must pass validation before proceeding.

When active, the gate emits a `review/start` message carrying `ReviewStartParams` and awaits a `ReviewStartResponse`. This exchange pauses the operation until the back‑end confirms the snippet meets linting, security, and policy requirements.

## How the Review Gate Protocol Works

### The review/start Message Exchange

According to the protocol definitions in [`app-server-protocol.d.ts`](https://github.com/openai/codex-plugin-cc/blob/main/app-server-protocol.d.ts), the review gate initiates a structured message exchange:

- **`ReviewStartParams`** – Contains the generated snippet, target language, and execution context.
- **`ReviewStartResponse`** – Returns the approval status; if `approved` is false, the response includes diagnostic issues requiring human or automated review.

The front‑end sends this message via the App‑Server client, which blocks further execution until the response resolves.

### Backend Validation Logic

The back‑end implementation—potentially located in [`plugins/codex/review-gate.ts`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/review-gate.ts) if present—executes a series of optional checks:

- **Linting** – Syntax and style validation against project‑specific rules.
- **Security scans** – Static analysis for secrets, injection risks, or vulnerable patterns.
- **Policy compliance** – Verification against organizational coding standards.

If any check fails, the gate returns a rejection with detailed diagnostics, preventing the snippet from reaching [`review-ui.ts`](https://github.com/openai/codex-plugin-cc/blob/main/review-ui.ts) for final application.

### Frontend Review UI

When the gate detects issues, the front‑end component in [`plugins/codex/scripts/client/review-ui.ts`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/scripts/client/review-ui.ts) renders the diagnostic output. This interface allows reviewers to inspect failures, approve exceptions, or reject the generation, ensuring only vetted code proceeds to the editor or file system.

## How to Enable the Review Gate

The review gate is **disabled by default** to maintain low latency during rapid prototyping. You can activate it using two configuration methods.

### Environment Variable Configuration

Set the `CODIX_REVIEW_GATE` variable to any truthy value before starting the plugin server:

```bash
export CODIX_REVIEW_GATE=1
npm start

```

This approach is ideal for CI/CD pipelines and containerized deployments where runtime flags are preferred over file edits.

### Plugin Configuration File

Alternatively, add the flag to [`plugins/codex/config.json`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/config.json):

```json
// plugins/codex/config.json
{
  "reviewGate": true,
  "otherOption": "value"
}

```

Changes to this file require a server restart to take effect, making it suitable for persistent team environments where the configuration should be version controlled.

## When to Enable the Codex Review Gate

Enable the gate when code quality and audit trails outweigh raw generation speed.

### Enterprise and Security‑Sensitive Projects

Activate the gate for repositories handling privileged data or production deployments. The additional validation layer in [`review-gate.ts`](https://github.com/openai/codex-plugin-cc/blob/main/review-gate.ts) prevents vulnerable code from entering your codebase, satisfying enterprise security requirements.

### Regulated Environments

Organizations subject to SOC 2, HIPAA, or GDPR benefit from the mandatory audit trail created by the `review/start` protocol. Every generation event becomes a documented checkpoint, demonstrating compliance with external regulations.

### Team Collaboration Workflows

When multiple developers share a single Codex instance, the gate enforces consistent style and prevents accidental regressions. The [`review-ui.ts`](https://github.com/openai/codex-plugin-cc/blob/main/review-ui.ts) component acts as a centralized checkpoint where senior developers can mentor junior staff on generated code quality.

### When to Leave It Disabled

Disable the gate for personal scripts, rapid prototyping, or low‑risk languages like Markdown. In these contexts, the latency introduced by the `ReviewStartResponse` wait state impedes experimentation without providing meaningful safety benefits.

## Implementation Example

The following TypeScript snippet demonstrates how the front‑end handles the review gate protocol using the App‑Server client:

```typescript
import { sendMessage } from './appServerProtocol';

async function requestReview(snippet: string) {
  const response = await sendMessage('review/start', {
    code: snippet,
    language: 'typescript'
  });

  if (response.approved) {
    // snippet passed the gate – proceed
    applySnippet(snippet);
  } else {
    // show reviewer UI with diagnostics
    showReviewUI(response.issues);
  }
}

```

This pattern ensures your integration respects the protocol defined in [`app-server-protocol.d.ts`](https://github.com/openai/codex-plugin-cc/blob/main/app-server-protocol.d.ts), pausing execution until the back‑end validation completes.

## Summary

- The **Codex plugin review gate** is a protocol‑based checkpoint defined in [`plugins/codex/scripts/lib/app-server-protocol.d.ts`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/scripts/lib/app-server-protocol.d.ts) that intercepts generated code via the `review/start` message.
- It is **disabled by default** and can be enabled via the `CODIX_REVIEW_GATE` environment variable or `"reviewGate": true` in [`plugins/codex/config.json`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/config.json).
- When enabled, the gate runs linting, security, and policy checks before returning a `ReviewStartResponse` that determines whether the snippet proceeds.
- Enable the gate for **enterprise**, **regulated**, or **multi‑developer** environments; disable it for rapid prototyping or low‑risk tasks.

## Frequently Asked Questions

### What file defines the review gate protocol messages?

The protocol definitions reside in [`plugins/codex/scripts/lib/app-server-protocol.d.ts`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/scripts/lib/app-server-protocol.d.ts). This file specifies the `review/start` message structure, `ReviewStartParams`, and `ReviewStartResponse` types that govern the gate’s communication flow.

### Is the review gate enabled by default in the Codex plugin?

No. The gate is **disabled by default** to prioritize low‑latency responses. You must explicitly set `CODIX_REVIEW_GATE=1` or add `"reviewGate": true` to [`plugins/codex/config.json`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/config.json) to activate the validation layer.

### How do I disable the review gate once enabled?

Remove the `CODIX_REVIEW_GATE` environment variable or set it to an empty value, and set `"reviewGate": false` (or remove the key) from [`plugins/codex/config.json`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/config.json). Restart the plugin server to apply the changes.

### What types of checks run when the review gate is active?

The back‑end executes configurable checks that typically include **linting**, **security scans** for secrets or vulnerabilities, and **policy compliance** validation. The specific implementations may reside in [`plugins/codex/review-gate.ts`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/review-gate.ts) or external validation services invoked during the `review/start` handling.