Connect Codex to AI Assistant in JetBrains IDE

JetBrains IDEs (IntelliJ IDEA, WebStorm, PyCharm, etc.) include AI Assistant, which can work not only with cloud agents but also with ACP agents (Agent Communication Protocol). This makes it possible to connect Codex and use it as a full-featured AI agent right inside the IDE.

Step 1. Install Codex CLI

On macOS, the easiest option is Homebrew:

brew install codex

After installation, sign in:

codex login

Your browser will open — log in to your OpenAI account and confirm access.

Step 2. Install the ACP Adapter for Codex

JetBrains AI Assistant works with Codex through a dedicated ACP adapter.

Unfortunately, at the time of writing, the adapter is not available in Homebrew, so you need to install it manually.

Repository: https://github.com/zed-industries/codex-acp

Download the binary from the releases page for your platform, unpack it, and place it somewhere convenient, for example:

~/IdeaProjects/codex-acp

Step 3. Configure AI Assistant in JetBrains

1. Open the AI Assistant toolbar
2. Click the three dots (⋯)
3. Select Configure ACP Agents
4. In the opened config, add a new agent with the following configuration:

{
  "agent_servers": {
    "Codex": {
      "command": "/Users/clericode/IdeaProjects/codex-acp",
      "args": [],
      "env": {
        "RUST_LOG": "info"
      }
    }
  }
}

Important:

• the path in command must be absolute
• it must point to the codex-acp binary

Step 4. Use Codex in the IDE

After that:

• in the AI Chat tab, you can select Codex as the agent

• you can choose:

  • a model

  • an operating mode:

    • Read-only — read-only access
    • Agent — access to the project
    • Full access — full access to the entire computer

Choosing the Codex agent and mode

Different models vary in speed and token usage — it makes sense to pick the best option for your tasks.

What’s next

Now you can use Codex as a full-featured AI assistant right inside JetBrains IDE:

• analyze code and architecture, refactor, and more
• avoid switching to the browser
• avoid paying for separate AI credits if you already have a ChatGPT Plus subscription

Source: https://clericode.com