Query WFS Geoportail layers

Instructions

Implementation Reference

• src/index.ts:616-639 (handler)

  Handler function that processes input parameters, queries the external WFS Geoportail API endpoint via apiRequest, and returns formatted GeoJSON response as JSON or Markdown.

  async (params) => {
    const { source, response_format, ...queryParams } = params;
  
    const data = await apiRequest<unknown>("/wfs-geoportail/search", {
      params: {
        source,
        ...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,
      `WFS Geoportail - ${source}`
    );
    return {
      content: [{ type: "text", text: truncateResponse(markdown, CHARACTER_LIMIT) }],
    };
  }

• src/index.ts:603-608 (schema)

  Zod input schema defining parameters: source (WFS layer), geom (GeoJSON), pagination (_limit, _start), and response_format.

  inputSchema: z.object({
    source: z.string().describe("WFS data source name (e.g., 'BDTOPO_V3:commune')"),
    geom: GeometrySchema.describe("GeoJSON geometry (required, in WGS84/EPSG:4326)"),
    ...PaginationSchema,
    response_format: ResponseFormatSchema,
  }).strict(),

• src/index.ts:581-640 (registration)

  Registers the 'ign_wfs_geoportail' MCP tool with metadata, schema, and inline handler function.

  server.registerTool(
    "ign_wfs_geoportail",
    {
      title: "Query WFS Geoportail layers",
      description: `Generic query interface for Geoportail WFS layers.
  
  This tool provides access to various WFS layers from the IGN Geoportail. It allows querying any WFS layer by intersection with a geometry.
  
  Args:
    - source (string): WFS data source name (e.g., "BDTOPO_V3:commune", "LIMITES_ADMINISTRATIVES_EXPRESS.LATEST:commune")
    - geom (string): GeoJSON geometry to intersect (required, in WGS84/EPSG:4326)
    - _limit (number): Max results (1-1000)
    - _start (number): Pagination offset
  
  Returns:
    GeoJSON FeatureCollection with features from the requested layer.
  
  Note: Only WGS84 (EPSG:4326) geometries are supported.
  
  Examples:
    - "Get BDTOPO communes at this point" -> source="BDTOPO_V3:commune", geom={"type":"Point","coordinates":[2.35,48.85]}
    - "Find buildings in this area" -> source="BDTOPO_V3:batiment", geom=...`,
      inputSchema: z.object({
        source: z.string().describe("WFS data source name (e.g., 'BDTOPO_V3:commune')"),
        geom: GeometrySchema.describe("GeoJSON geometry (required, in WGS84/EPSG:4326)"),
        ...PaginationSchema,
        response_format: ResponseFormatSchema,
      }).strict(),
      annotations: {
        readOnlyHint: true,
        destructiveHint: false,
        idempotentHint: true,
        openWorldHint: true,
      },
    },
    async (params) => {
      const { source, response_format, ...queryParams } = params;
  
      const data = await apiRequest<unknown>("/wfs-geoportail/search", {
        params: {
          source,
          ...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,
        `WFS Geoportail - ${source}`
      );
      return {
        content: [{ type: "text", text: truncateResponse(markdown, CHARACTER_LIMIT) }],
      };
    }
  );