CC GUI: The Best Free Open‑Source Companion for Claude Code and Codex in IntelliJ IDEA

Problem

JetBrains IDE users who rely on Claude Code often have to write code in IDEA while interacting with the AI through a separate terminal, constantly switching windows and losing context.

Comparison with VS Code

VS Code’s official Anthropic extension embeds the conversation, diff and file references in a sidebar, providing a seamless experience.

CC GUI Overview

CC GUI (formerly Claude Code GUI) is an IntelliJ IDEA plugin that repackages the Claude Code and Codex CLI agents into a full‑screen graphical interface, bringing all operations that were previously scattered across terminals, screenshot tools, file managers and browsers into a single panel.

Unlike the lightweight ACP (Agent Client Protocol) integration, which only connects the CLI, CC GUI adds GUI‑based session management, image input and a skill system.

Compatibility with ACP

ACP is a generic protocol that lets any IDE act as a client for any AI agent. IDEA already supports agents such as Cursor, Claude Code, Codex, Gemini CLI and Kimi CLI via ACP. CC GUI is a separate path; both can be installed and used side‑by‑side. Use ACP for lightweight, long‑running tasks; use CC GUI for visual workflows.

Installation (≈10 minutes)

Install the plugin : Settings → Plugins, search “CC GUI”, install, and the entry appears in the right‑hand toolbar.

Provider configuration : Choose one of four methods – Anthropic Console API Key, import local settings.json, import via cc-switch, or custom third‑party endpoint. Most users prefer the “import local settings.json” for zero‑configuration.

Start a conversation : Use the right‑hand panel to chat. A simple prompt like “Analyze the current project structure” demonstrates context awareness.

Planning mode example

When integrating UnionPay payment, direct code changes are risky. Using the /plan command, the AI scans the project, reads relevant service code and UnionPay documentation, then returns a structured implementation plan that lists files to modify, new classes, required SDKs, signature handling and async callbacks.

The key difference is that the CLI mode would immediately rewrite code, whereas /plan forces the AI to propose a plan first, allowing the developer to review before execution, reducing failure rates for low‑tolerance scenarios.

Built‑in utilities

Token/Cost statistics – shows token usage and estimated cost per session.

AI‑generated commit messages – creates Conventional Commits messages from staged diffs.

AI review – runs the AI over a diff before a PR to catch edge cases, null pointers and naming issues.

Skill browser – enables or disables Skills with a single click inside the GUI.

Session history – search and delete past conversations on the MCP server.

Choosing an AI agent for JetBrains

If you already use Claude Code or Codex, install CC GUI and reuse your subscription.

If you want a free quota with deep Java ecosystem support, try Qoder.

If you are in the Tencent cloud ecosystem, consider CodeBuddy.

You can install all three; they do not conflict and can be switched per scenario.

Conclusion

CC GUI does not create new AI capabilities; it refocuses development effort from “where to use AI” to “what to use AI for”. Its three core goals are to embed Claude Code and Codex inside IDEA, enforce disciplined AI‑coding workflows via /plan and AI review, and embed team code‑review standards as reusable Skills.

For JetBrains power users already using Claude Code or Codex, the free MIT‑licensed plugin with 3.3 k stars is a quick, low‑risk addition.