#!/usr/bin/env node
/**
* Chhart MCP Server
* Enables AI assistants to create flowcharts and Sankey diagrams on chhart.app
*/
import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
import {
CallToolRequestSchema,
ListToolsRequestSchema,
} from '@modelcontextprotocol/sdk/types.js';
import {
createFlowchart,
createFlowchartSchema,
type CreateFlowchartInput
} from './tools/createFlowchart.js';
import {
createSankey,
createSankeySchema,
type CreateSankeyInput
} from './tools/createSankey.js';
import {
getSyntaxHelp,
getSyntaxHelpSchema,
type GetSyntaxHelpInput
} from './tools/getSyntaxHelp.js';
// Create MCP server instance
const server = new Server(
{
name: 'chhart-mcp-server',
version: '1.0.2',
},
{
capabilities: {
tools: {},
},
}
);
// Register tool list handler
server.setRequestHandler(ListToolsRequestSchema, async () => {
return {
tools: [
{
name: 'create_flowchart',
description: 'Create a flowchart on chhart.app using text-based DSL syntax. Returns a shareable URL to view and edit the flowchart.',
inputSchema: {
type: 'object',
properties: {
content: {
type: 'string',
description: 'Flowchart content in Chhart DSL format (indented outline structure)'
},
title: {
type: 'string',
description: 'Optional title for the flowchart'
}
},
required: ['content']
}
},
{
name: 'create_sankey',
description: 'Create a Sankey diagram on chhart.app showing flows between nodes. Returns a shareable URL to view and edit the diagram.',
inputSchema: {
type: 'object',
properties: {
content: {
type: 'string',
description: 'Sankey diagram content in Chhart DSL format (indented outline with [value=N] attributes)'
},
title: {
type: 'string',
description: 'Optional title for the Sankey diagram'
}
},
required: ['content']
}
},
{
name: 'get_syntax_help',
description: 'Get documentation and examples for Chhart\'s flowchart and Sankey diagram syntax.',
inputSchema: {
type: 'object',
properties: {
type: {
type: 'string',
enum: ['flowchart', 'sankey', 'all'],
description: 'Which syntax documentation to retrieve',
default: 'all'
}
}
}
}
]
};
});
// Register tool execution handler
server.setRequestHandler(CallToolRequestSchema, async (request) => {
const { name, arguments: args } = request.params;
try {
switch (name) {
case 'create_flowchart': {
const input = createFlowchartSchema.parse(args) as CreateFlowchartInput;
return await createFlowchart(input);
}
case 'create_sankey': {
const input = createSankeySchema.parse(args) as CreateSankeyInput;
return await createSankey(input);
}
case 'get_syntax_help': {
const input = getSyntaxHelpSchema.parse(args || {}) as GetSyntaxHelpInput;
return await getSyntaxHelp(input);
}
default:
return {
content: [
{
type: 'text' as const,
text: `Unknown tool: ${name}`
}
],
isError: true
};
}
} catch (error) {
const errorMessage = error instanceof Error ? error.message : String(error);
return {
content: [
{
type: 'text' as const,
text: `Error executing tool ${name}: ${errorMessage}`
}
],
isError: true
};
}
});
// Start server
async function main() {
const transport = new StdioServerTransport();
await server.connect(transport);
// Log to stderr so it doesn't interfere with stdio communication
console.error('Chhart MCP Server running on stdio');
console.error('Available tools: create_flowchart, create_sankey, get_syntax_help');
}
main().catch((error) => {
console.error('Fatal error starting server:', error);
process.exit(1);
});
