AL LSP for Agents

Code intelligence for AL (Microsoft Dynamics 365 Business Central) that works with GitHub Copilot agent mode and Claude Code.

This extension gives AI agents the same code navigation tools that developers use — go to definition, find references, call hierarchy, and code quality diagnostics — so they can understand and modify AL code with full semantic awareness.

Features

Language Model Tools for Copilot

When using GitHub Copilot in agent mode, these tools become available:

Enriched Hover

Hover results are automatically enriched with:

• XML doc comments from source code (summaries, parameter descriptions, return values)
• Field properties from table definitions (Caption, FieldClass, CalcFormula, TableRelation, Editable, etc.)
• Action properties from page definitions (RunObject, ToolTip, Image, ShortcutKey, etc.)

All declared properties are extracted — if a property isn't shown, it genuinely isn't set in the source code.

Code Quality Diagnostics

Real-time diagnostics powered by al-call-hierarchy:

• Unused procedures (no callers)
• High cyclomatic complexity
• Too many parameters
• High fan-in (many callers)
• Long methods

Note: Code quality diagnostics are disabled by default in the editor. To enable them, set alLspForAgents.enableCodeQualityDiagnostics to true in your VS Code settings. The bclsp_codeQualityDiagnostics tool always works regardless of this setting.

Configurable Thresholds

Diagnostic thresholds are configurable at two levels. All values are optional — missing values use sensible defaults.

Global Defaults

Set defaults for all your projects in ~/.al-call-hierarchy/config.json:

{
  "diagnostics": {
    "complexity": { "warning": 8, "critical": 15 },
    "unusedProcedures": false
  }
}

Per-Workspace Overrides

Override for a specific project in {workspace}/.al-call-hierarchy.json:

{
  "diagnostics": {
    "complexity": { "enabled": true, "warning": 8, "critical": 15 },
    "parameters": { "enabled": false },
    "lineCount": { "warning": 30, "critical": 80 },
    "fanIn": { "enabled": false },
    "unusedProcedures": false
  }
}

Config is merged per field: built-in defaults → global → workspace. A workspace config only needs to specify fields it wants to override. Set "enabled": false on any category to disable it entirely.

Call Hierarchy

Full incoming and outgoing call analysis for procedures, including cross-file navigation and event subscriber detection.

Prerequisites

• VS Code with the AL Language extension installed
• An AL project with app.json and downloaded symbols (.alpackages)

The extension bundles all required binaries — no additional installation needed.

How It Works

The extension starts a Go wrapper that combines:

1. Microsoft AL Language Server — compiler-powered definitions, hover, references, and diagnostics
2. al-call-hierarchy — tree-sitter-powered call hierarchy, code lens, code quality diagnostics, and property extraction

The wrapper merges capabilities from both servers and presents a single enriched LSP interface.

Also Available for Claude Code

This project also provides Claude Code plugins for the same AL code intelligence:

/plugin marketplace add SShadowS/al-lsp-for-agents

See the GitHub repo for details.

License

MIT