MCP4GVA

Instructions

Implementation Reference

• typescript/src/index.ts:239-260 (handler)

  Handler for the gva_count tool: queries the ArcGIS FeatureServer with returnCountOnly=true to get the count of matching features and returns it as text content.

  case "gva_count": {
    // Count features
    const countArgs = args as CountArguments;
    const url = `${BASE_URL}/${LAYER_ID}/query`;
    const params: RequestParams = {
      where: countArgs.where || "1=1",
      returnCountOnly: "true",
      f: "json",
    };
  
    const data = await makeRequest(url, params);
    const count = data.count || 0;
  
    return {
      content: [
        {
          type: "text",
          text: `Total features matching query: ${count}`,
        },
      ],
    };
  }

• typescript/src/index.ts:138-152 (registration)

  Registration of the gva_count tool in the list_tools handler, including its schema definition.

  {
    name: "gva_count",
    description: "Count features matching a WHERE clause",
    inputSchema: {
      type: "object",
      properties: {
        where: {
          type: "string",
          description: 'SQL WHERE clause (e.g., "1=1" for all)',
          default: "1=1",
        },
      },
      required: [],
    },
  },

• typescript/src/index.ts:37-39 (schema)

  TypeScript interface defining the input arguments for the gva_count tool.

  interface CountArguments {
    where?: string;
  }

• mcp4gva/server.py:181-197 (handler)

  Python handler for the gva_count tool: similar logic to query count from ArcGIS FeatureServer.

  elif name == "gva_count":
      # Count features
      url = f"{BASE_URL}/{LAYER_ID}/query"
      params = {
          'where': arguments.get('where', '1=1'),
          'returnCountOnly': 'true',
          'f': 'json'
      }
  
      data = make_request(url, params)
      count = data.get('count', 0)
  
      return [TextContent(
          type="text",
          text=f"Total features matching query: {count}"
      )]

• mcp4gva/server.py:93-107 (registration)

  Registration of the gva_count tool in Python implementation, including input schema.

  Tool(
      name="gva_count",
      description="Count features matching a WHERE clause",
      inputSchema={
          "type": "object",
          "properties": {
              "where": {
                  "type": "string",
                  "description": "SQL WHERE clause (e.g., '1=1' for all)",
                  "default": "1=1"
              }
          },
          "required": []
      }
  ),