puml-lsp

LSP server for PlantUML files with link validation.

Features

• Syntax validation using PlantUML
• Link validation for [[file.ext Link]] references

Requirements

• Node.js >= 18
• Java (for PlantUML validation)

Installation

npm install -g puml-lsp

Usage (CLI)

puml-lsp

Or run directly:

node src/index.js

Usage (VS Code)

Option 1: Global install

npm install -g puml-lsp

Add to VS Code settings:

{
  "plantuml.server": "puml-lsp"
}

Option 2: Local install (recommended for development)

npm install --save-dev puml-lsp

Add to VS Code settings (Local LSP extension required):

{
  "localLsp.servers": {
    "puml": {
      "command": "node",
      "args": ["${workspaceFolder}/node_modules/puml-lsp/src/index.js"],
      "languages": ["plantuml"],
      "configuration": {
        "trace": false
      }
    }
  }
}

Or use the Local - Languages Server extension from the VS Code marketplace.

Troubleshooting

If LSP doesn't connect:

1. Make sure Java is installed: java -version
2. For global install, verify the command is in PATH: which puml-lsp
3. For local install, verify the path to src/index.js is correct
4. Check VS Code output panel for "PlantUML Language Server initialized" message