git:20260906.e62b9e9 to git:20260907.1811930

---

name: gnn-lsp-server

description: GNN Language Server Protocol integration. Use when starting editor diagnostics, checking hover behavior, or validating LSP support for GNN files.

---

# Core Skill: `lsp_server`

**Function**: Language Server Protocol implementation providing real-time GNN file diagnostics and hover information for LSP-compatible editors.

## Example Flow

```bash

# Start the GNN Language Server via CLI

gnn lsp

# Or directly via Python module

```

## Programmatic Usage

```python

from gnn.lsp import create_server, start_server

# Create and configure the LSP server

server = create_server()

# Start on stdio (standard usage for editor integration)

start_server()

```

## Features

- **Diagnostic Publishing**: Validates GNN sections, state-space variables, and connections on file open and save

- **Hover Information**: Displays variable name, dimensions, type, and default values at cursor position

- **Error Extraction**: Maps parse errors to line numbers for inline display in editors

- **Graceful Fallback**: Works without `pygls` by providing a clear installation message

- **VS Code Integration**: Compatible with any LSP client via stdio transport

## MCP Tools

This module registers tools with the GNN MCP server (see `mcp.py`):

- None