git:20260906.e62b9e9 to git:20260906.a82d4dd

# LSP Module — Agent Scaffolding

## Module Overview

**Purpose**: Language Server Protocol implementation for real-time diagnostics and hover information for GNN files.

**Pipeline Step**: Infrastructure module (not a numbered step)

**Category**: Infrastructure / Development Tools

**Status**: ✅ Production Ready

**Version**: 3.2.0

**Last Updated**: 2026-04-16

The LSP module implements a GNN Language Server using the Language Server Protocol. It provides real-time diagnostics and hover information for GNN model files in any LSP-compatible editor.

## Architecture

- **Pattern**: Infrastructure module (not a numbered pipeline step)

- **Framework**: `pygls` (Python Language Server)

- **Protocol**: LSP 3.x over stdio

- **Dependency**: Optional (`pygls` — graceful fallback when missing)

## Capabilities

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

## Key Functions

| Function | Description |

|----------|-------------|

| `create_server()` | Configure and return a `LanguageServer` instance |

| `start_server()` | Start the server on stdio |

| `_publish_diagnostics()` | Run GNN validation and publish results |

| `_get_hover()` | Generate hover info for a variable at a position |

## File Structure

```

├── AGENTS.md # This file

├── README.md # Usage guide

└── SPEC.md # Module specification

```

## References

- [README.md](README.md) — Usage guide

- [SPEC.md](SPEC.md) — Specification

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## Documentation

- **[README](README.md)**: Module Overview

- **[AGENTS](AGENTS.md)**: Agentic Workflows

- **[SPEC](SPEC.md)**: Architectural Specification

- **[SKILL](SKILL.md)**: Capability API