MCP4GVA

Instructions

Implementation Reference

• mcp4gva/server.py:162-179 (handler)

  The handler function for the 'gva_query' tool. It constructs the query parameters from the input arguments and makes an HTTP request to the ArcGIS FeatureServer /query endpoint, returning the JSON response as text content.

  elif name == "gva_query":
      # Query features
      url = f"{BASE_URL}/{LAYER_ID}/query"
      params = {
          'where': arguments.get('where', '1=1'),
          'outFields': arguments.get('out_fields', '*'),
          'returnGeometry': str(arguments.get('return_geometry', True)).lower(),
          'resultRecordCount': arguments.get('result_record_count', 10),
          'resultOffset': arguments.get('result_offset', 0),
          'f': 'json'
      }
  
      data = make_request(url, params)
  
      return [TextContent(
          type="text",
          text=json.dumps(data, indent=2, ensure_ascii=False)
      )]

• mcp4gva/server.py:58-92 (registration)

  Registration of the 'gva_query' tool in the list_tools function, including its description and detailed input schema.

  Tool(
      name="gva_query",
      description="Query features from the GVA GIS layer with SQL-like WHERE clause and optional parameters",
      inputSchema={
          "type": "object",
          "properties": {
              "where": {
                  "type": "string",
                  "description": "SQL WHERE clause (e.g., '1=1' for all, 'MUNICIPIO=\"Valencia\"')",
                  "default": "1=1"
              },
              "out_fields": {
                  "type": "string",
                  "description": "Comma-separated field names or '*' for all fields",
                  "default": "*"
              },
              "return_geometry": {
                  "type": "boolean",
                  "description": "Whether to return geometry data",
                  "default": True
              },
              "result_record_count": {
                  "type": "integer",
                  "description": "Maximum number of records to return",
                  "default": 10
              },
              "result_offset": {
                  "type": "integer",
                  "description": "Offset for pagination",
                  "default": 0
              }
          },
          "required": []
      }
  ),

• typescript/src/index.ts:214-237 (handler)

  The TypeScript handler for the 'gva_query' tool. Constructs query parameters and performs an HTTP request to the ArcGIS FeatureServer /query endpoint, returning the JSON response.

  case "gva_query": {
    // Query features
    const queryArgs = args as QueryArguments;
    const url = `${BASE_URL}/${LAYER_ID}/query`;
    const params: RequestParams = {
      where: queryArgs.where || "1=1",
      outFields: queryArgs.out_fields || "*",
      returnGeometry: String(queryArgs.return_geometry ?? true).toLowerCase(),
      resultRecordCount: queryArgs.result_record_count || 10,
      resultOffset: queryArgs.result_offset || 0,
      f: "json",
    };
  
    const data = await makeRequest(url, params);
  
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(data, null, 2),
        },
      ],
    };
  }

• typescript/src/index.ts:103-137 (registration)

  Registration of the 'gva_query' tool in the TypeScript list tools handler, including description and input schema.

  {
    name: "gva_query",
    description: "Query features from the GVA GIS layer with SQL-like WHERE clause and optional parameters",
    inputSchema: {
      type: "object",
      properties: {
        where: {
          type: "string",
          description: 'SQL WHERE clause (e.g., "1=1" for all, "MUNICIPIO=\'Valencia\'")',
          default: "1=1",
        },
        out_fields: {
          type: "string",
          description: "Comma-separated field names or '*' for all fields",
          default: "*",
        },
        return_geometry: {
          type: "boolean",
          description: "Whether to return geometry data",
          default: true,
        },
        result_record_count: {
          type: "number",
          description: "Maximum number of records to return",
          default: 10,
        },
        result_offset: {
          type: "number",
          description: "Offset for pagination",
          default: 0,
        },
      },
      required: [],
    },
  },

• mcp4gva/server.py:28-43 (helper)

  Shared helper function used by gva_query (and other tools) to perform HTTP requests to the ArcGIS API with browser-like headers to avoid blocking.

  def make_request(url: str, params: dict) -> dict:
      """Make HTTP request to the API with browser-like headers"""
      headers = {
          'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
          'Accept': 'application/json, text/plain, */*',
          'Accept-Language': 'es-ES,es;q=0.9,en;q=0.8'
      }
  
      try:
          response = requests.get(url, params=params, headers=headers, timeout=30)
          response.raise_for_status()
          return response.json()
      except requests.RequestException as e:
          logger.error(f"Request failed: {e}")
          raise