CodePlanGUI

A lightweight JetBrains IDEA plugin that connects to any OpenAI-compatible API endpoint — bringing streaming Chat and one-click Commit Message generation directly into your IDE, without binding to any specific vendor account.

中文文档

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Why

Most AI plugins for IntelliJ IDEA require a vendor account (GitHub Copilot, 通义灵码, MarsCode). Developers in China who already have API keys for services like Alibaba Qianwen, Doubao, or DeepSeek have no good option to use them directly inside IDEA.

CodePlanGUI fills that gap: configure any endpoint + key, and get a fully-featured Chat sidebar and Commit Message generator without leaving your IDE.

Features

Feature	Details
Chat Sidebar	Streams tokens one-by-one via SSE, rendered as Markdown with syntax-highlighted code blocks
Context-Aware	Toggle to include the current file (or selected text) in every prompt; auto-truncates at 300 lines / 12,000 chars
Ask AI	Right-click selected code in the editor → Ask AI
Commit Message Generation	Click ✨ in the Git Commit dialog to generate a message from your staged diff (Conventional Commits format)
Multi-Provider Management	Add, edit, remove, and switch between any number of OpenAI-compatible endpoints
Test Connection	Instant connectivity check with specific HTTP status + error body on failure
Secure Key Storage	API keys are stored in IDEA's built-in PasswordSafe, never written to disk in plain text

Requirements

• IntelliJ IDEA 2023.1 or later (Community or Ultimate)
• JetBrains Runtime (JBR) — bundled with IDEA, required for the embedded browser (JCEF)
• JDK 17 (for building)

Installation

From disk (manual)

1. Build or download CodePlanGUI-0.1.0.zip (see Build)
2. Open IDEA → Settings → Plugins → ⚙ → Install Plugin from Disk...
3. Select the zip → OK → Restart IDEA

Configuration

1. Go to Settings → Tools → CodePlanGUI

2. In the Providers tab, click Add to add a provider:

   Field	Example
   Name	GPT-4o
   Endpoint	https://api.openai.com/v1
   Model	gpt-4o
   API Key	stored securely

3. Click Test Connection to verify — you'll see a specific error (HTTP code + body) if it fails

4. Click OK to save

Common provider endpoints:

Service	Endpoint
OpenAI	https://api.openai.com/v1
DeepSeek	https://api.deepseek.com/v1
Alibaba Qianwen (百炼)	https://dashscope.aliyuncs.com/compatible-mode/v1
Doubao (豆包)	https://ark.cn-beijing.volces.com/api/v3
Local Ollama	http://localhost:11434/v1

5. Open the CodePlanGUI tool window on the right sidebar and start chatting

Build

# Build webview and plugin zip
JAVA_HOME=/path/to/jdk17 ./gradlew buildWebview buildPlugin

# Output
build/distributions/CodePlanGUI-0.1.0.zip

Requires JDK 17. Gradle 8.5 does not support JDK 21+.

Run in sandbox IDE

JAVA_HOME=/path/to/jdk17 ./gradlew buildWebview runIde

Roadmap

See docs/roadmap.md for the full phase plan, engineering tasks, and acceptance criteria.

Explicitly not available today:

• Command execution from chat
• Agent mode or slash commands
• Cloud account sync or a hosted backend service

Not planned:

• Account / cloud sync (local keys only, zero server)
• Bundled models
• Non-OpenAI-compatible private protocols

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Architecture

┌─────────────────────────────────────────────┐
│  IDEA Plugin (Kotlin)                        │
│  ├── Tool Window (ChatPanel)                 │
│  ├── Settings (PersistentStateComponent)     │
│  │   └── API Keys → PasswordSafe            │
│  ├── Git Commit Action (GenerateCommitMsg)   │
│  └── JCEF Browser Host                      │
│           ↕  Kotlin ↔ JS Bridge             │
│  ┌─────────────────────────────────────────┐ │
│  │  React 19 Frontend (Chat UI)            │ │
│  │  Ant Design 5 · marked · highlight.js   │ │
│  └─────────────────────────────────────────┘ │
│           ↕  OkHttp SSE                      │
└─────────────────────────────────────────────┘
             ↓
  External AI API (OpenAI-compatible)
  阿里百炼 / 豆包 / DeepSeek / OpenAI / …

Key design decisions:

• No bridge daemon — Unlike plugins that manage a subprocess (e.g. Claude Code CLI), CodePlanGUI calls REST APIs directly from the plugin, keeping the architecture simple.
• JCEF over native Swing — Streaming Markdown with syntax highlighting is impractical in Swing; JCEF provides a full browser runtime.
• loadHTML not loadURL("file://...") — Plugin JARs cannot be addressed by file URLs at runtime; the frontend HTML is read via getResourceAsStream and injected as a string.
• PasswordSafe for keys — API keys are stored in IDEA's credential store, never written to codePlanGUI.xml which may be committed to VCS.

Tech Stack

Layer	Technology
Plugin shell	Kotlin 1.9 + Gradle (Groovy DSL)
IntelliJ Platform	org.jetbrains.intellij.platform v2.1.0
Embedded browser	JCEF (JetBrains Chromium Embedded Framework)
Frontend	React 19 + TypeScript + Ant Design 5 + Vite
HTTP / SSE	OkHttp 4.12 + okhttp-sse
Serialization	kotlinx-serialization-json 1.6.3
Concurrency	kotlinx-coroutines-core 1.7.3

License

MIT