User Location MCP Server

Overview

Minimal MCP server (buddai-location) that stores and retrieves the user’s current location from MongoDB. It is invoked through STDIO using the Docker image referenced in user_location.mcp.yml.

Components

• index.js – spins up the MCP server, registering two tools for reading/writing the location.
• mongo.js – MongoDB helper that persists a single document (userId: "current") in the locations collection.
• package.json / Dockerfile – Node 22 image using @modelcontextprotocol/sdk with production dependencies only.

Exposed MCP tools

Tool	Purpose	Input
get_user_location	Returns the stored location string, defaulting to "Las Rozas de Madrid, España" when no document exists.	none
set_user_location	Upserts the current location and timestamp for userId="current".	location (string).

The helpers maintain a single cached MongoDB connection and close it only when the process exits.

Configuration

The host launch definition (mcp_servers/user_location.mcp.yml) expects a MongoDB URI:

user_location:
  transport: stdio
  command: docker
  args:
    - run
    - --init
    - -i
    - --rm
    - --network
    - buddai_net
    - -e
    - MONGO_URI
    - buddai/mcp-user-location
  env:
    MONGO_URI: "${MONGO_URI}"

Provide MONGO_URI in the MCP host environment. The server writes to the default database returned by the URI and creates/uses a locations collection.

Set DEBUG=mcp_location:* to enable debug output.

Running locally

1. Install Node.js ≥ 20 and run npm install.
2. Ensure MongoDB is reachable and export MONGO_URI plus optional DEBUG.
3. Launch the MCP server with node index.js and connect via an MCP client over STDIO.

Docker usage

docker build -t buddai/mcp-user-location mcp_servers/location

Run (matching the host configuration):

docker network create buddai_net                  # once
MONGO_URI=mongodb://mongo:27017/buddai \
docker run --rm --init -i \
  --network buddai_net \
  -e MONGO_URI \
  -e DEBUG=mcp_location:* \
  buddai/mcp-user-location

Development notes

• This service caches the Mongo client globally; when you change connection parameters, restart the process so the new URI is applied.
• Tests are inherited from other projects and are currently stale.
• Only a single logical user is supported (userId="current"). Extend mongo.js if you need multi-user support.

Troubleshooting

• No updates stored: verify that the Mongo user has write permissions and that the locations collection exists in the target database.
• Unexpected default location: call set_user_location at least once; the fallback string indicates no record was found.