monaco-editor-lsp-next

✨ A seamless Next.js integration of the Monaco Editor with robust LSP support – all without SSR hassles.

⚠️ LSP Configuration and Environment Variable Limitations

Warning: Pre-built Image LSP Configuration Limitations

The pre-built Docker image cfngc4594/monaco-editor-lsp-next is configured to connect exclusively to ws://localhost:4594/clangd and ws://localhost:4595/clangd. This is due to the LSP configuration being set via NEXT_PUBLIC environment variables during the image build process.

• Build-Time Freezing: As per the Next.js official documentation, NEXT_PUBLIC variables are frozen at build time, and subsequent changes are ineffective.
• Local LSP Server Dependency: Therefore, the pre-built image can only connect to the specified local LSP servers.
• Custom Configuration Requirement: If you wish to define your own LSP configuration via environment variables, you cannot use the pre-built image. Instead, you must:
  • Clone the source code.
  • Set your desired environment variables.
  • Manually build the Docker image.

Upcoming Improvements (v0.0.1):

To address these limitations, v0.0.1 will implement the officially recommended API approach for retrieving LSP configurations, enabling runtime dynamic LSP server configuration without image rebuilding.

⚠️ WSL Users: Critical Configuration

🐧 Network Mode Requirement

When using Windows Subsystem for Linux (WSL), you must configure your network mode as Mirrored to ensure proper LSP server connectivity. Standard WSL network configurations may create IPv6 conflicts that block Monaco-LSP communication.

🔧 Mirror Mode Setup:

1. Open WSL settings ⚙️
2. Navigate to Network section 🌐
3. Select Mirrored mode 🔄
4. Restart WSL instance 💻

Complete these steps before launching the editor for seamless LSP integration! 🎉

🚀 Getting Started

🐳 Docker Deployment (Recommended)

Deploy the project quickly using pre-built Docker images:

# Clone the repository
git clone https://github.com/cfngc4594/monaco-editor-lsp-next
cd monaco-editor-lsp-next

# Start the application with pre-built images
docker compose up -d

🔨 Local Manual Build

Build the images locally and start the containers:

# Clone the repository
git clone https://github.com/cfngc4594/monaco-editor-lsp-next
cd monaco-editor-lsp-next

# Build and start containers using the local configuration
docker compose -f compose.local.yml up -d --build

🛠 Development Mode

Set up a development environment with hot-reloading:

# Clone the repository
git clone https://github.com/cfngc4594/monaco-editor-lsp-next
cd monaco-editor-lsp-next

# Start only the LSP containers
docker compose up -d lsp-c lsp-cpp
# Or use the local configuration
# docker compose -f compose.local.yml up -d --build lsp-c lsp-cpp

# Install dependencies and start the development server
bun install
bun run dev

⚙️ Technical Configuration

LSP Server Mapping

Language	LSP Server	Port
C	clangd	4594
C++	clangd	4595

📦 Dependency Management

🔒 Version Lock Requirements

Critical Pairing:

Package	Max Version	Reference
monaco-editor	≤0.36.1	Compatibility Matrix
monaco-languageclient	≤5.0.1

Version Lock Rationale:

1. API Stability

   • Newer monaco-editor (≥0.40.0) breaks monaco-languageclient integration
   • v0.36.1 matches @codingame/monaco-vscode-api@1.76.9 requirements

2. LSP Feature Breakdown

   • Version mismatches disable:
     • Auto textDocument/didOpen events
     • textDocument/inlayHint resolution
     • textDocument/documentLink functionality

3. Version Conflict

   • @codingame package versioning (e.g., 11.1.2) ≠ monaco-editor versions (e.g., 0.36.1)
   • @monaco-editor/react depends on monaco-editor versioning scheme

Failure Indicators:

• ✔️ WebSocket connection established
• ❌ Missing syntax highlighting
• ❌ No autocomplete suggestions
• ❌ Silent LSP initialization failures

🎨 Shiki Compatibility Notice

Syntax highlighting depends on rehype-pretty-code's deprecated getHighlighter API from shiki@legacy.

Key Points:

• Affected File: src/components/mdx-preview.tsx

• Dependency Chain: rehype-pretty-code → shiki@legacy

• Version Constraints:

  "shiki": "<=2.5.0"
  "@shikijs/monaco": "<=2.5.0"
  

Maintenance Note:
While shiki@3.0.0+ introduces modern APIs (createHighlighter/getSingletonHighlighter), upgrading requires rehype-pretty-code updates. Track progress here.