IGN API Carto MCP Server

Instructions

Implementation Reference

• src/index.ts:383-404 (handler)

  The handler function for 'ign_get_nature_areas' tool. It takes parameters including layer and optional geom/id_mnhn/etc., calls the API endpoint `/nature/${layer}` with query params, fetches GeoJSON data, and returns either raw JSON or Markdown-formatted response.

  async (params) => {
    const { layer, response_format, ...queryParams } = params;
    const endpoint = `/nature/${layer}`;
    
    const data = await apiRequest<unknown>(endpoint, {
      params: queryParams as Record<string, string | number | boolean | undefined>,
    });
  
    if (response_format === ResponseFormat.JSON) {
      return {
        content: [{ type: "text", text: JSON.stringify(data, null, 2) }],
      };
    }
  
    const markdown = formatGeoJSONToMarkdown(
      data as import("./types.js").GeoJSONFeatureCollection,
      `Espaces naturels - ${layer}`
    );
    return {
      content: [{ type: "text", text: truncateResponse(markdown, CHARACTER_LIMIT) }],
    };
  }

• src/index.ts:323-335 (schema)

  Zod schema defining the enum of valid 'layer' values specific to the ign_get_nature_areas tool (protected natural areas layers).

  const NatureLayerSchema = z.enum([
    "natura2000-oiseaux",
    "natura2000-habitat", 
    "rnc",
    "rnn",
    "rncf",
    "pn",
    "pnr",
    "znieff1",
    "znieff2",
    "sic",
    "zps",
  ] as const);

• src/index.ts:337-405 (registration)

  Registration of the 'ign_get_nature_areas' tool using server.registerTool, including title, description, inputSchema (using NatureLayerSchema), annotations, and inline handler function.

  server.registerTool(
    "ign_get_nature_areas",
    {
      title: "Get protected natural areas",
      description: `Query protected natural areas in France (Natura 2000, ZNIEFF, national parks, etc.).
  
  Available layers:
  - natura2000-oiseaux: Natura 2000 bird directive sites
  - natura2000-habitat: Natura 2000 habitat directive sites
  - rnc: Corsican natural reserves
  - rnn: National natural reserves
  - rncf: Hunting and wildlife natural reserves
  - pn: National parks
  - pnr: Regional natural parks
  - znieff1: ZNIEFF type 1 (remarkable ecological areas)
  - znieff2: ZNIEFF type 2 (large natural ensembles)
  - sic: Sites of Community Importance
  - zps: Special Protection Areas
  
  Args:
    - layer (string): Nature layer to query
    - geom (string, optional): GeoJSON geometry to intersect
    - id_mnhn (string, optional): MNHN identifier
    - _limit (number): Max results
    - _start (number): Pagination offset
  
  Returns:
    GeoJSON FeatureCollection with protected area boundaries and attributes.
  
  Examples:
    - "Find Natura 2000 sites at this location" -> layer="natura2000-habitat", geom=...
    - "Get ZNIEFF zones near Paris" -> layer="znieff1", geom=...`,
      inputSchema: z.object({
        layer: NatureLayerSchema.describe("Nature layer to query"),
        geom: GeometrySchema.optional(),
        id_mnhn: z.string().optional().describe("MNHN (Natural History Museum) identifier"),
        ...PaginationSchema,
        response_format: ResponseFormatSchema,
      }).strict(),
      annotations: {
        readOnlyHint: true,
        destructiveHint: false,
        idempotentHint: true,
        openWorldHint: true,
      },
    },
    async (params) => {
      const { layer, response_format, ...queryParams } = params;
      const endpoint = `/nature/${layer}`;
      
      const data = await apiRequest<unknown>(endpoint, {
        params: queryParams as Record<string, string | number | boolean | undefined>,
      });
  
      if (response_format === ResponseFormat.JSON) {
        return {
          content: [{ type: "text", text: JSON.stringify(data, null, 2) }],
        };
      }
  
      const markdown = formatGeoJSONToMarkdown(
        data as import("./types.js").GeoJSONFeatureCollection,
        `Espaces naturels - ${layer}`
      );
      return {
        content: [{ type: "text", text: truncateResponse(markdown, CHARACTER_LIMIT) }],
      };
    }
  );