ALCops MCP Server

An MCP server that brings AL code fixes to AI assistants, and re-exposes Microsoft's own AL MCP tools alongside them. Lets Claude, Cursor, and other MCP clients compile Business Central AL projects, browse rules, and apply fixes — all without leaving the conversation.

Microsoft's almcp covers compiling, diagnostics, symbols, publishing, tests and translations, but has no code-fix capability at all (its LSP mode explicitly advertises CodeActionProvider = false) and no way to enumerate rules. Those two gaps are what this server adds; everything else it proxies straight through, so you get one endpoint instead of two.

Quick Start

dotnet tool install -g Microsoft.Dynamics.BusinessCentral.Development.Tools
dotnet tool install -g ALCops.Mcp

Add to your .mcp.json (Claude Code) or claude_desktop_config.json (Claude Desktop):

{
  "mcpServers": {
    "alcops": {
      "command": "alcops-mcp"
    }
  }
}

If you already have the AL Language VS Code extension, the first install is optional — the server finds the tools in the extension instead.

Requirements

• .NET 10.0 SDK or Runtime
• BC Development Tools v18.0 or higher, from either the Microsoft.Dynamics.BusinessCentral.Development.Tools dotnet tool or the AL Language VS Code extension

Note: v16 and earlier are not supported — the BC Development Tools DLLs introduced breaking API changes in v17. almcp also first shipped in v17, so on an older toolchain only the native tools below are available.

Tools

Native (this server)

Tool	Description
list_rules	List analyzer rules with metadata (ID, title, severity, category, cop).
get_fixes	Get available code fixes for a specific diagnostic at a location.
apply_fix	Apply a code fix to resolve a diagnostic. Writes the fixed content directly to the file on disk.
apply_fix_all	Apply a code fix to every occurrence of a diagnostic rule across a project or a single file (like VS Code's "Fix all in workspace"). Writes to disk unless dryRun is set.

Proxied from Microsoft's almcp

al_compile, al_build, al_getdiagnostics, al_addproject, al_downloadsymbols, al_symbolsearch, al_symbolrelations, al_getpackagedependencies, al_inspectpage, al_publish, al_run_tests, al_searchtranslations, al_writetranslation, al_auth_login, al_auth_logout — the exact set depends on your installed version.

almcp is started in the background, so the native tools are available the moment the server comes up; the al_* tools appear once it has loaded your project (the server sends tools/list_changed, and hosts that don't support it see them on their next tool listing).

Pass --no-proxy to serve only the native tools. Use it when your agent already registers Microsoft's almcp itself, so the al_* tools don't show up twice.

al_compile defaults to onlyErrors: true. Nearly every ALCops rule is a warning, so pass onlyErrors: false or you will see no cop diagnostics at all.

Analyzers

Analyzers are not bundled. The server loads exactly what your project configures via al.codeAnalyzers in .vscode/settings.json (AL-Go's rulesetFile and the custom.ruleset.json / app.ruleset.json conventions are honored too). That includes ALCops' cops, BC's standard cops (${CodeCop}, ${UICop}, ${PerTenantExtensionCop}, ${AppSourceCop}), and any third-party analyzer.

This is deliberate: bundling pinned cop DLLs beside whatever Nav.CodeAnalysis you have installed is what produced AD0001 / MissingMethodException failures (#10). Resolving both from your own toolchain makes that mismatch impossible.

{
  "al.codeAnalyzers": [
    "${CodeCop}",
    "${analyzerFolder}ALCops.LinterCop.dll"
  ]
}

The same analyzer, ruleset and al.packageCachePath configuration is passed to the child almcp at startup, so al_compile and get_fixes always agree about which rules run, which are suppressed, and where symbols come from.

Browse the ALCops rules reference at alcops.dev/docs/analyzers.

BC DevTools Resolution

The DevTools DLLs and almcp live in the same directory in both delivery channels, so one lookup serves both. On startup the server searches, in order, and logs which one won:

1. --devtools-path <dir>
2. BCDEVELOPMENTTOOLSPATH environment variable
3. dotnet tool store (~/.dotnet/tools/.store/…) — highest version wins
4. AL Language VS Code extension bin/ — highest version wins

If none match, the server exits with the install command rather than starting up degraded. Nothing is downloaded at runtime.

CLI Options

Option	Description
--devtools-path <dir>	Use this BC DevTools directory instead of probing.
--projects <dir>[;<dir>]	Work on these projects instead of scanning down from the working directory for app.json. A directory that is not itself a project is scanned for projects beneath it; entries with none are ignored with a warning.
--no-proxy	Serve only the native tools; do not start almcp.

Arguments almcp understands — --codeanalyzers, --rulesetpath, --settingspath, --enablecodeanalysis, --enableexternalrulesets, --locale, --noauth, --nolog and friends — are forwarded to the child process and override anything discovered from your project.

Contributing

Contributions are welcome! Whether it's a new tool, a bug report, or a pull request — all input helps.

• 🐛 Report a bug — File an Issue
• 🔧 Submit a PR — Fork the repo, create a branch, and open a pull request

License

This project is licensed under the MIT License.