MCP-GeoViz: OpenStreetMap Data Visualization Module

This module integrates OpenStreetMap capabilities into the MCP framework, enabling users to retrieve and display geospatial information directly within the MCP environment.

Core Capabilities

• Client-side map rendering utilizing Leaflet and OpenStreetMap tiles.
• Asynchronous data pipeline employing Server-Sent Events (SSE) for pushing updates from the server.
• A suite of MCP-specific controls for manipulating the map display (e.g., adding graphical elements like markers/polygons, adjusting the viewport).
• Direct execution interface for SQL queries against the underlying OpenStreetMap data stored in a PostGIS-enabled PostgreSQL instance.

Deployment Configuration

To initialize the service, configure your environment as follows (example claude_desktop_config.json):

{
  "mcpServers": {
    "OSM PostgreSQL Server": {
      "command": "/Users/wiseman/.local/bin/uv",
      "args": [
        "run",
        "--env-file",
        ".env",
        "--with",
        "mcp[cli]",
        "--with",
        "psycopg2",
        "--with-editable",
        "/Users/wiseman/src/mcp-osm",
        "--directory",
        "/Users/wiseman/src/mcp-osm",
        "mcp",
        "run",
        "mcp.py"
      ]
    }
  }
}

Upon successful initialization of the MCP backend server, the interactive map visualization tool becomes accessible via HTTP at http://localhost:8889/.

Runtime Parameters

Configuration of the visualization service is managed through environment variables:

• FLASK_HOST - Specifies the network interface binding for the Flask web application (defaults to 127.0.0.1).
• FLASK_PORT - Determines the TCP port for the map server (defaults to 8889).
• PGHOST - The hostname or IP address for the backing PostgreSQL database (defaults to localhost).
• PGPORT - The port number for the PostgreSQL connection (defaults to 5432).
• PGDB - The target database schema name (defaults to osm).
• PGUSER - Credentials for database access: username (defaults to postgres).
• PGPASSWORD - Credentials for database access: secret key (defaults to postgres).

Available MCP Interfaces

The following remote procedure calls (RPCs) are exposed for programmatic map manipulation:

• get_map_view - Retrieves the current geographic extents displayed on the map.
• set_map_view - Adjusts the map's center point and zoom level to specified coordinates or boundary box.
• set_map_title - Updates the textual label displayed in the lower-right corner of the map component.
• add_map_marker - Places a symbolic point of interest at specified latitude/longitude.
• add_map_line - Renders a path connecting a sequence of specified coordinate pairs.
• add_map_polygon - Draws a closed polygonal area defined by an ordered list of vertices.
• query_osm_postgres - Executes arbitrary SQL commands against the integrated OpenStreetMap data repository.