mcpAD

A FastMCP server that exposes the msad Active Directory / LDAP library as MCP tools.

Built with Python 3.14 and uv. It reuses the typed, public msad API (search users/groups, memberships, account status). All tools are read-only.

Tools

Returned attributes

By default get_user / find_users return a useful attribute set that includes manager — the distinguished name (DN) of the user's manager, e.g. CN=Anna Bianchi,OU=Staff,DC=group,DC=example,DC=com. Group lookups include managedBy, the DN of the group's owner.

To expand a manager (or any DN-valued field) into a full record, call get_by_dn with that DN. This is a direct, efficient lookup (the DN is used as the search base), so an agent can do: get_user("mrossi") → read manager → get_by_dn("<that DN>").

Related MCP server: Koppla

Authentication & connection

The server has no connection settings of its own: it reuses the msad configuration file, ~/.msad.toml by default (create it with msad init). Each tool call opens a short-lived connection through msad.connect().

Domain parameters (~/.msad.toml)

[defaults]
domain = "group"              # used when a tool call omits `domain`

[domains.group]
host = "dc.example.com"       # hostname only (no scheme, no :port)
search_base = "dc=group,dc=example,dc=com"
port = 636                    # default: 389
use_ssl = true                # default: false  (true = LDAPS)
# user = "svc_account"        # optional (see auth below)
# password = "..."            # optional

You can declare several [domains.<name>] blocks and pick one per call with the tool's domain argument, or globally via MSAD_DOMAIN.

Overrides via environment

• MSAD_DOMAIN — default domain when a tool call omits domain

• MSAD_CONFIG_FILE — path to an alternative TOML config

Authentication modes

The mode is chosen automatically from the domain block:

• Kerberos (SASL) — when user/password are not both set (the default). Obtain a ticket first:

  kinit                # or: kinit <user>@REALM

  The server relies on the system Kerberos ticket cache (or a keytab via KRB5_CLIENT_KTNAME). If the ticket is missing or expired, tools fail with a clean MsadConnectionError message. When running as a background/remote service, make sure that process can see a valid ticket or keytab.

• User / password — when both user and password are set. Simple LDAP bind. The password is stored in clear text in the TOML, so restrict the file permissions (chmod 600 ~/.msad.toml).

  Note: setting only one of user/password silently falls back to Kerberos. Set both, or neither.

Use LDAPS (port = 636, use_ssl = true) whenever possible.

Running

The Makefile wraps the common cases. Transport, host and port are configurable:

make start-stdio                        # stdio (for local MCP clients)
make start-http                         # streamable-http on 127.0.0.1:8000
make start-http HOST=0.0.0.0 PORT=9000  # bind elsewhere
make start-sse                          # sse transport
make start TRANSPORT=streamable-http PORT=9000   # generic form

Equivalent raw commands (the server reads MCP_TRANSPORT / MCP_HOST / MCP_PORT from the environment):

uv run mcpad                                        # stdio (default)
MCP_TRANSPORT=streamable-http MCP_PORT=9000 uv run mcpad

Registering the server with an MCP client / agent

MCP clients (Claude Desktop, IDE agents, custom agents, ...) usually accept a JSON config with a mcpServers map. Two deployment styles:

Local (stdio) — the client launches the server

The client spawns the process and talks to it over stdio. This is the simplest setup and keeps everything on your machine (including your Kerberos ticket).

{
  "mcpServers": {
    "mcpAD": {
      "command": "uv",
      "args": [
        "run",
        "--directory", "/path/to/mcpAD",
        "mcpad"
      ],
      "env": {
        "MSAD_DOMAIN": "group"
      }
    }
  }
}

Notes:

• --directory makes uv use this project's environment regardless of the client's working directory.

• Kerberos: the spawned process inherits your environment, so a ticket obtained with kinit in the same user session is used automatically. For an unattended client, point it at a keytab (e.g. add "KRB5_CLIENT_KTNAME": "/path/to.keytab" to env).

Remote (streamable-http) — the server runs as a service

Start the server as a long-running HTTP service, then point the client at its URL. Useful when the server runs on a host that has AD/Kerberos access while the client runs elsewhere.

Start the service:

make start-http HOST=0.0.0.0 PORT=9000
# serves the MCP endpoint at http://<host>:9000/mcp

Client config referencing the URL:

{
  "mcpServers": {
    "mcpAD": {
      "transport": "http",
      "url": "http://mcp-host.example.com:9000/mcp"
    }
  }
}

Notes:

• The default streamable-http path is /mcp.

• The server itself performs no client authentication; if you expose it beyond localhost, put it behind a reverse proxy / network controls and treat the AD credentials on that host accordingly.

• Kerberos runs where the server runs: that host needs a valid ticket or a keytab, not the client.

Development

uv sync
uv run python -c "import asyncio; from mcpad import mcp; print(asyncio.run(mcp.list_tools()))"

The msad dependency is installed as an editable local path (../msad), so library changes are picked up immediately.