#!/usr/bin/env node
import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import {
CallToolRequestSchema,
ErrorCode,
ListToolsRequestSchema,
McpError,
} from "@modelcontextprotocol/sdk/types.js";
import highsLoader, { Highs } from "highs";
import { zodToJsonSchema } from "zod-to-json-schema";
import { OptimizationArgsSchema } from "./schemas.js";
import { encode } from "./encode.js";
import { decode } from "./decode.js";
import packageJson from "../package.json";
const TOOL_NAME = "optimize-mip-lp-tool";
const server = new Server(
{
name: "highs-mcp",
version: packageJson.version,
},
{
capabilities: {
tools: {},
},
},
);
// List tools
server.setRequestHandler(ListToolsRequestSchema, async () => ({
tools: [
{
name: TOOL_NAME,
description:
"Solve linear programming (LP), mixed-integer programming (MIP), or quadratic programming (QP) problems using HiGHS solver. " +
"QP support includes convex quadratic objectives (minimize c^T x + 0.5 x^T Q x) where Q must be positive semidefinite. " +
"Limitations: QP only supports continuous variables (no MIQP), and when specifying Q matrix values should be doubled to account for the 0.5 factor.",
inputSchema: zodToJsonSchema(OptimizationArgsSchema, {
$refStrategy: "none",
}),
},
],
}));
let highsInstance: Highs | null = null;
async function getHighsInstance() {
if (!highsInstance) {
highsInstance = await highsLoader();
}
return highsInstance;
}
// Solve optimization problem
server.setRequestHandler(CallToolRequestSchema, async (request) => {
if (request.params.name !== TOOL_NAME) {
throw new McpError(ErrorCode.MethodNotFound, `Unknown tool: ${request.params.name}`);
}
// Validate input using Zod
const validationResult = OptimizationArgsSchema.safeParse(request.params.arguments);
if (!validationResult.success) {
const errorMessages = validationResult.error.errors.map((e) => {
// Include path information for better error messages
const path = e.path.join(".");
return path ? `${path}: ${e.message}` : e.message;
});
throw new McpError(ErrorCode.InvalidParams, `Invalid parameters: ${errorMessages.join(", ")}`, {
errors: errorMessages,
});
}
const { problem, options } = validationResult.data;
try {
const highs = await getHighsInstance();
// Convert problem to LP format
const lpString = encode(problem);
// Solve the problem
const result = highs.solve(lpString, options || {});
// Decode the result
const decodedResult = decode(result, problem);
return {
content: [
{
type: "text",
text: JSON.stringify(decodedResult, null, 2),
},
],
};
} catch (error) {
throw new McpError(ErrorCode.InternalError, `Failed to solve optimization problem: ${error}`);
}
});
async function main() {
// Check Node.js version
const nodeVersion = process.version;
const majorVersion = parseInt(nodeVersion.split(".")[0].substring(1));
console.error(`Node.js version: ${nodeVersion}`);
console.error(`Starting HiGHS MCP server v${packageJson.version}...`);
// Check if Node.js version is >= 16.0.0
if (majorVersion < 16) {
throw new Error(
`HiGHS MCP server requires Node.js version 16.0.0 or higher. Current version: ${nodeVersion}. ` +
`Please upgrade your Node.js installation to version 16.0.0 or higher.`,
);
}
const transport = new StdioServerTransport();
console.error("Connecting to stdio transport...");
await server.connect(transport);
console.error("HiGHS MCP server running - ready to solve optimization problems");
}
main().catch((error) => {
console.error("Server error:", error);
process.exit(1);
});
