Arma 3 MCP server: SQF reference and linter for AI agents

It is free and open source (MIT), needs no account or API key, and runs on Windows, macOS and Linux. It covers every scripting command, every BIS_fnc_* function and the core concept pages: data types, locality, the scheduler, event handlers.

What the agent gets

What lint_sqf reports:

Checked 3 lines: 2 errors, 1 warnings, 0 notes.

1:8 error: Unknown command setUnitHealth (used as a binary command).
2:1 error: setPos needs a left operand. Syntax: `object setPos pos`.
3:4 warning: ctrlSetEventHandler is deprecated. Use ctrlAddEventHandler instead.

The linter only reports what cannot be valid SQF, so it stays quiet on correct code. Run over the 5,500 SQF examples on the wiki, it reports 23 errors, nearly all of them config or prose pasted into code blocks.

Install

All you need is Node.js 18 or newer. Where a client has plugins, the plugin is the easiest way: it adds the MCP server and the sqf skill, which tells the agent to look commands up and lint SQF before showing it. Otherwise add the server to the client's MCP settings; every client starts the same command, npx -y a3ref-mcp.

AI agents asked to install the server: use the terminal command of the client you run in, then tell the user to restart the client or reload its MCP servers.

Claude Code

Plugin. Type in Claude Code:

/plugin marketplace add a3ref/mcp
/plugin install a3ref@a3ref

Server only, for every project (leave out --scope user for the current project only):

claude mcp add --scope user a3ref -- npx -y a3ref-mcp

Check with /mcp in Claude Code: a3ref should be listed as connected.

Codex

Plugin. The Codex CLI, the Codex IDE extension and the ChatGPT desktop app share plugins and settings, so one install covers all three:

codex plugin marketplace add a3ref/mcp
codex plugin add a3ref@a3ref

Or, after adding the marketplace, install a3ref from the Plugins directory of the ChatGPT desktop app.

Server only:

codex mcp add a3ref -- npx -y a3ref-mcp

Or add it yourself to ~/.codex/config.toml (or to .codex/config.toml in a trusted project):

[mcp_servers.a3ref]
command = "npx"
args = ["-y", "a3ref-mcp"]

Check with codex mcp list in a terminal or /mcp in the Codex CLI.

Antigravity

Plugin. Plugins installed with the CLI or the Antigravity app are available in the app, the IDE and the CLI:

agy plugin install https://github.com/a3ref/mcp

Server only. The Antigravity app, the IDE and the CLI (agy) read the same file, ~/.gemini/config/mcp_config.json (or .agents/mcp_config.json for one workspace). In the IDE, the agent panel's menu (…), MCP Servers, Manage MCP Servers, View raw config opens it.

{
  "mcpServers": {
    "a3ref": {
      "command": "npx",
      "args": ["-y", "a3ref-mcp"]
    }
  }
}

In the CLI, /mcp opens the MCP manager: it shows whether the server is connected and reloads the settings. Antigravity CLI replaced Gemini CLI in 2026; set the server up there as shown here.

OpenCode

Add the server to ~/.config/opencode/opencode.json for every project, or to opencode.json in one project:

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "a3ref": {
      "type": "local",
      "command": ["npx", "-y", "a3ref-mcp"],
      "enabled": true
    }
  }
}

Check with opencode mcp list. For the sqf skill as well, save its SKILL.md as ~/.config/opencode/skills/sqf/SKILL.md. OpenCode plugins are code modules rather than packages of servers and skills, so there is no plugin to install.

Claude Desktop

Settings, Developer, Edit Config opens claude_desktop_config.json (in %APPDATA%\Claude\ on Windows, ~/Library/Application Support/Claude/ on macOS). Add the server and restart Claude Desktop:

{
  "mcpServers": {
    "a3ref": {
      "command": "npx",
      "args": ["-y", "a3ref-mcp"]
    }
  }
}

Cursor

In ~/.cursor/mcp.json for every project, or .cursor/mcp.json in one project:

{
  "mcpServers": {
    "a3ref": {
      "command": "npx",
      "args": ["-y", "a3ref-mcp"]
    }
  }
}

Windsurf

{
  "mcpServers": {
    "a3ref": {
      "command": "npx",
      "args": ["-y", "a3ref-mcp"]
    }
  }
}

VS Code

For Copilot agent mode, in the workspace:

{
  "servers": {
    "a3ref": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "a3ref-mcp"]
    }
  }
}

Other clients

Any client that runs local (stdio) MCP servers works: give it the command npx with the arguments -y a3ref-mcp. Most take the mcpServers JSON shown for Cursor.

Try it

Ask the agent something that needs the reference, for example:

• "Which command deletes a vehicle with its crew? Check the locality."
• "Spawn a group of four NATO riflemen near the player, then lint the script."
• "What changed on the Arma 3 wiki this week?"

The agent should call search, get or lint_sqf instead of answering from memory.

Troubleshooting

• The server does not start. Run node --version (18 or newer is needed), then npx -y a3ref-mcp in a terminal: it should start and wait for input without printing anything (Ctrl+C ends it).
• npm error code EALLOWGIT. An older setup runs npx -y github:a3ref/mcp, which npm 12 refuses (it no longer installs packages straight from git). Replace github:a3ref/mcp with a3ref-mcp.
• Windows: the client cannot find npx. Some clients do not run .cmd files directly. Use the command cmd with the arguments /c npx -y a3ref-mcp, e.g. "command": "cmd", "args": ["/c", "npx", "-y", "a3ref-mcp"].
• Your own copy of the site. The server reads https://wiki.arma3.io/; set the environment variable A3REF_BASE_URL to read a mirror instead.

How it works

The server downloads what it needs from this site (index.json, syntax.json and the pages the agent asks for) and keeps it in memory for an hour. Nothing is bundled, so answers follow the wiki without updating the server.

No MCP client? Every page of this site is also plain Markdown and JSON at a stable URL; an agent that can fetch web pages can start from llms.txt. The source code, issues and release notes are on GitHub.