AL MCP & Test Skills

Until now the agent could write code and see compiler errors — but it couldn't run tests. You've been doing that manually: publish, run the test tool, copy failures back.

This page sets up two tools that automate that loop for every feature from here on.

AL MCP — what it does

Once connected, the agent can build, read diagnostics, and run tests without you intervening. The implement → build → test → fix cycle runs autonomously.

run-al-tests skill — why you also need it

AL MCP's al_run_tests currently does not support UI tests — tests that open a TestPage and navigate to a record will fail, even when the code is correct. This is a known limitation reported to Microsoft: the AL MCP opens each test in a separate client session, so data created inside the test isn't visible to the TestPage.

The run-al-tests skill uses BcContainerHelper with the standard BC test runner, which runs everything in a single shared session. All tests pass.

The pattern: AL MCP drives the implement loop. run-al-tests confirms before merge.

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Set up AL MCP

Prerequisites: .NET 8 runtime installed. BC container on Windows authentication (required for al_run_tests).

CursorVS Code + GitHub CopilotClaude Code

1. Add altool to PATH — run once in PowerShell:

$altoolDir = (Get-ChildItem "$env:USERPROFILE\.vscode\extensions" -Filter "ms-dynamics-smb.al-*" -Directory | Sort-Object Name -Descending | Select-Object -First 1).FullName + "\bin\win32"
$currentPath = [Environment]::GetEnvironmentVariable("PATH", "User")
if ($currentPath -notlike "*$altoolDir*") {
    [Environment]::SetEnvironmentVariable("PATH", "$altoolDir;$currentPath", "User")
    Write-Host "Added to PATH: $altoolDir"
} else { Write-Host "Already in PATH" }

2. Add to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "al": {
      "command": "altool",
      "args": ["launchmcpserver", "--transport", "stdio"]
    }
  }
}

3. Full restart (not just Reload Window).

Check Cursor Settings → Tools & Integrations → MCP — green dot, tools listed.

1. Verify altool version matches your AL extension:

altool --version
# Expected: 18.x.x matching your AL extension

If the wrong version runs, ensure the AL 18 bin folder is first in your PATH (same script as the Cursor tab).

2. Create or edit mcp.json globally:

{
  "mcpServers": {
    "al": {
      "command": "altool",
      "args": ["launchmcpserver", "--transport", "stdio"]
    }
  }
}

3. Reload Window (Ctrl+Shift+P → Developer: Reload Window).

Check GitHub Copilot Chat → Agent mode — AL tools should be available.

1. Install AL tools globally:

dotnet tool install Microsoft.Dynamics.BusinessCentral.Development.Tools --interactive --prerelease --global

2. Add the MCP server:

claude mcp add al al launchmcpserver <path-to-project> --transport stdio

Restart Claude Code.

Verify

altool --version  # Expected: 18.x.x.xxxxx+...

MCP settings should list: al_addproject, al_compile, al_build, al_getdiagnostics, al_symbolsearch, al_downloadsymbols, al_publish, al_run_tests, al_auth_login, al_auth_logout.

launch.json for tests

al_run_tests reads from test/.vscode/launch.json. Must be Windows authentication and startupCompany must be set to the company you want to test:

{
  "configurations": [{
    "type": "al",
    "request": "launch",
    "name": "Local Sandbox (bc-28)",
    "server": "http://bc-28",
    "serverInstance": "BC",
    "port": 7049,
    "tenant": "default",
    "authentication": "Windows",
    "startupCompany": "CRONUS USA, Inc."
  }]
}

Reference

AL MCP Server — Microsoft Learn

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run-al-tests skill

Ships with the repo at .cursor/skills/run-al-tests/. To use it, just ask the agent to run the run-al-tests skill.

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Test comparison

	AL MCP	run-al-tests skill	BC Test Tool
Uses AL test runner	No	Yes	Yes
TestPage tests	May fail	Pass	Pass
CI-friendly	Yes	Yes	No

Implement →