MCP Server Chart

Instructions

Implementation Reference

• src/server.ts:71-75 (handler)

  MCP server request handler for tools/call, which receives the tool name (e.g. generate_area_chart) and arguments, and dispatches to callTool.
  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); });
• src/utils/callTool.ts:44-110 (handler)

  Core tool execution logic: maps tool name to chart type (generate_area_chart -> 'area'), validates args against area schema, generates and returns chart URL.
  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/charts/area.ts:24-58 (schema)

  Zod schema defining the input parameters and validation for the generate_area_chart tool.
  const schema = { data: z .array(data) .describe( "Data for area chart, it should be an array of objects, each object contains a `time` field and a `value` field, such as, [{ time: '2015', value: 23 }, { time: '2016', value: 32 }], when stacking is needed for area, the data should contain a `group` field, such as, [{ time: '2015', value: 23, group: 'A' }, { time: '2015', value: 32, group: 'B' }].", ) .nonempty({ message: "Area chart data cannot be empty." }), stack: z .boolean() .optional() .default(false) .describe( "Whether stacking is enabled. When enabled, area charts require a 'group' field in the data.", ), style: z .object({ backgroundColor: BackgroundColorSchema, palette: PaletteSchema, texture: TextureSchema, lineWidth: z .number() .optional() .describe("Line width for the lines of chart, such as 4."), }) .optional() .describe( "Style configuration for the chart with a JSON object, optional.", ), theme: ThemeSchema, width: WidthSchema, height: HeightSchema, title: TitleSchema, axisXTitle: AxisXTitleSchema, axisYTitle: AxisYTitleSchema, };
• src/server.ts:66-68 (registration)

  MCP tools/list request handler that returns the list of available tools, including the descriptor for generate_area_chart from Charts.area.tool.
  server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: getEnabledTools().map((chart) => chart.tool), }));
• src/utils/callTool.ts:9-36 (helper)

  Mapping of tool names to internal chart types; generate_area_chart maps to 'area' for use in Charts[chartType] and generateChartUrl.
  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_waterfall_chart: "waterfall", generate_word_cloud_chart: "word-cloud", } as const;