MCP Server Chart

Instructions

Implementation Reference

• src/utils/callTool.ts:43-110 (handler)

  The shared handler function that executes generate_organization_chart (and other chart tools) by mapping the tool name to chart type 'organization-chart', validating arguments against the schema, generating the chart URL via generateChartUrl, and returning the MCP tool result.
  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/organization-chart.ts:37-65 (schema)

  Defines the Zod input schema for the tool parameters and the tool metadata object with name, description, and inputSchema.
  const schema = { data: OrganizationChartNodeSchema.describe( "Data for organization chart which is a hierarchical structure, such as, { name: 'CEO', description: 'Chief Executive Officer', children: [{ name: 'CTO', description: 'Chief Technology Officer', children: [{ name: 'Dev Manager', description: 'Development Manager' }] }] }, and the maximum depth is 3.", ), orient: z .enum(["horizontal", "vertical"]) .default("vertical") .describe( "Orientation of the organization chart, either horizontal or vertical. Default is vertical, when the level of the chart is more than 3, it is recommended to use horizontal orientation.", ), style: z .object({ texture: TextureSchema, }) .optional() .describe( "Style configuration for the chart with a JSON object, optional.", ), theme: ThemeSchema, width: WidthSchema, height: HeightSchema, }; const tool = { name: "generate_organization_chart", description: "Generate an organization chart to visualize the hierarchical structure of an organization, such as, a diagram showing the relationship between a CEO and their direct reports.", inputSchema: zodToJsonSchema(schema), };
• src/server.ts:64-77 (registration)

  Sets up MCP server request handlers: ListTools exposes all chart tools (including generate_organization_chart) from Charts exports; CallTool dispatches invocations to callTool function.
  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/utils/generate.ts:12-39 (helper)

  Core helper that POSTs the chart type ('organization-chart') and options to the visualization service API to generate and return the rendered chart URL.
  export async function generateChartUrl( type: string, // biome-ignore lint/suspicious/noExplicitAny: <explanation> options: Record<string, any>, ): Promise<string> { const url = getVisRequestServer(); const response = await axios.post( url, { type, ...options, 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:9-35 (helper)

  Mapping from tool name 'generate_organization_chart' to internal chart type 'organization-chart' used by the handler.
  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;