MCP Server Chart

Instructions

Implementation Reference

• src/utils/generate.ts:56-82 (handler)

  The generateMap function executes the core logic for map-based tools like generate_path_map by sending the tool name and input to the external visualization service server and returning the result.
  export async function generateMap( tool: string, input: unknown, ): Promise<ResponseResult> { const url = getVisRequestServer(); const response = await axios.post( url, { serviceId: getServiceIdentifier(), tool, input, source: "mcp-server-chart", }, { headers: { "Content-Type": "application/json", }, }, ); const { success, errorMessage, resultObj } = response.data; if (!success) { throw new Error(errorMessage); } return resultObj; }
• src/utils/callTool.ts:43-110 (handler)

  The callTool function is the primary dispatcher for all chart generation tools, invoked by the MCP server. For 'generate_path_map', it validates input using the specific schema, identifies it as a map chart, and invokes generateMap.
  export async function callTool(tool: string, args: object = {}) { logger.info(`Calling tool: ${tool}`); const chartType = CHART_TYPE_MAP[tool as keyof typeof CHART_TYPE_MAP]; if (!chartType) { logger.error(`Unknown tool: ${tool}`); throw new McpError(ErrorCode.MethodNotFound, `Unknown tool: ${tool}.`); } try { // Validate input using Zod before sending to API. // Select the appropriate schema based on the chart type. const schema = Charts[chartType].schema; if (schema) { // Use safeParse instead of parse and try-catch. const result = z.object(schema).safeParse(args); if (!result.success) { logger.error(`Invalid parameters: ${result.error.message}`); throw new McpError( ErrorCode.InvalidParams, `Invalid parameters: ${result.error.message}`, ); } } const isMapChartTool = [ "generate_district_map", "generate_path_map", "generate_pin_map", ].includes(tool); if (isMapChartTool) { // For map charts, we use the generateMap function, and return the mcp result. const { metadata, ...result } = await generateMap(tool, args); return result; } const url = await generateChartUrl(chartType, args); logger.info(`Generated chart URL: ${url}`); return { content: [ { type: "text", text: url, }, ], _meta: { description: "This is the chart's spec and configuration, which can be renderred to corresponding chart by AntV GPT-Vis chart components.", spec: { type: chartType, ...args }, }, }; // biome-ignore lint/suspicious/noExplicitAny: <explanation> } catch (error: any) { logger.error( `Failed to generate chart: ${error.message || "Unknown error"}.`, ); if (error instanceof McpError) throw error; if (error instanceof ValidateError) throw new McpError(ErrorCode.InvalidParams, error.message); throw new McpError( ErrorCode.InternalError, `Failed to generate chart: ${error?.message || "Unknown error."}`, ); } }
• src/server.ts:64-77 (registration)

  Registers the MCP ListTools and CallTool request handlers. The ListTools dynamically includes the 'generate_path_map' tool spec from the charts exports. The CallTool handler delegates to callTool.
  function setupToolHandlers(server: Server): void { logger.info("setting up tool handlers..."); server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: getEnabledTools().map((chart) => chart.tool), })); // biome-ignore lint/suspicious/noExplicitAny: <explanation> server.setRequestHandler(CallToolRequestSchema, async (request: any) => { logger.info("calling tool", request.params.name, request.params.arguments); return await callTool(request.params.name, request.params.arguments); }); logger.info("tool handlers set up"); }
• src/charts/path-map.ts:10-30 (schema)

  Defines the Zod input schema and the tool specification (name, description, inputSchema) for 'generate_path_map', exported for use in tool listing and validation.
  const schema = { title: MapTitleSchema, data: z .array( z.object({ data: POIsSchema }).describe("The route and places along it."), ) .nonempty("At least one route is required.") .describe( 'Routes, each group represents all POIs along a route. For example, [{ "data": ["西安钟楼", "西安大唐不夜城", "西安大雁塔"] }, { "data": ["西安曲江池公园", "西安回民街"] }]', ), width: MapWidthSchema, height: MapHeightSchema, }; // https://modelcontextprotocol.io/specification/2025-03-26/server/tools#listing-tools const tool = { name: "generate_path_map", description: "Generate a route map to display the user's planned route, such as travel guide routes.", inputSchema: zodToJsonSchema(schema), };
• src/utils/callTool.ts:9-35 (helper)

  CHART_TYPE_MAP provides the mapping from tool name 'generate_path_map' to the chart module 'path-map' for schema lookup and processing.
  const CHART_TYPE_MAP = { generate_area_chart: "area", generate_bar_chart: "bar", generate_boxplot_chart: "boxplot", generate_column_chart: "column", generate_district_map: "district-map", generate_dual_axes_chart: "dual-axes", generate_fishbone_diagram: "fishbone-diagram", generate_flow_diagram: "flow-diagram", generate_funnel_chart: "funnel", generate_histogram_chart: "histogram", generate_line_chart: "line", generate_liquid_chart: "liquid", generate_mind_map: "mind-map", generate_network_graph: "network-graph", generate_organization_chart: "organization-chart", generate_path_map: "path-map", generate_pie_chart: "pie", generate_pin_map: "pin-map", generate_radar_chart: "radar", generate_sankey_chart: "sankey", generate_scatter_chart: "scatter", generate_treemap_chart: "treemap", generate_venn_chart: "venn", generate_violin_chart: "violin", generate_word_cloud_chart: "word-cloud", } as const;