MCP Geocoding Tutorial

Background

Installing the MCP server on your computer

1. Clone the git repository

   The MCP server code is open source and hosted on GitHub.

   git clone git@github.com:OpenCageData/opencage-geocoding-mcp.git
   

   or

   git clone https://github.com/OpenCageData/opencage-geocoding-mcp.git
   

2. Switch into the repository directory

   cd opencage-geocoding-mcp
   

3. Install dependencies

   You will need to have node installed. Then run:

   npm install
   

4. Configure Claude Desktop

   On MacOS the config file should be ~/Library/Application Support/Claude/claude_desktop_config.json but you can also navigate to the file via the menu. Select Settings > Developer > Edit Config

   This is how Claude knows the MCP is available, how to call it, and how the LLM knows your OpenCage geocoding API key.

   Add this configuration:

   {
     "mcpServers": {
       "opencage-geocoding": {
         "command": "node",
         "args": ["/ABSOLUTE/PATH/TO/opencage-geocoding-mcp/build/index.js"],
         "env": {
           "OPENCAGE_API_KEY": "YOUR-API-KEY"
         }
       }
     }
   }
   
   

   Be sure to edit the args entry so it points to the directory where you installed the MCP.

5. Restart Claude Desktop

   So that the new configuration is used.

Using the MCP

You should now be able to make geocoding requests from within Claude Desktop simply by formulating a prompt involving geocoding.

For example try geocode the coordinates 52.5432379, 13.4142133

Note that the first time the MCP is used you will be prompted to give permission.

The LLM should recognize that this request can be answered by the MCP and hand the query off to our geocoding API

You can expand the response to get more details, including the actual API request if you want to see the full JSON response returned by the API.

Some example prompts

• "Where is Les Vans, France? Which Department is it in?"
• "What are the coordinates of Trafalgar Square, London?"
• "What are the coordinates of Pappelallee 78, Berlin?"
• "What is the address at -36.84694, 174.73662?"

Other commands

• "geocoding-assistant"

  provides an overview of how the MCP works and available commands

• "geocoding-assistant"

  If you are a free-trial user or one-time plan customer this command checks your current API usage and rate limits (subscription customers don't have hard limits, so this information is not returned for them), and also confirms that the API is working well (returning status 200).

Send us your feedback

As with all things in the realm of AI, this space is evolving very quickly. It's not currently entirely clear what the exact best practices are, nor what information we should make available to the LLM. Please let us know how you are using the MCP and if there are things we can change to make the service more useful.