import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { z } from "zod";
export interface ByulMcpOptions {
baseUrl?: string;
}
const DEFAULT_BASE_URL = "https://api.byul.ai/api/v2";
// Helper to call Byul REST API with required headers
async function callByulApi(path: string, params: Record<string, string | number | boolean | undefined> = {}, options?: ByulMcpOptions) {
const baseUrl = options?.baseUrl ?? DEFAULT_BASE_URL;
// Normalize to avoid dropping base path when path starts with "/"
const normalizedBase = baseUrl.endsWith("/") ? baseUrl : `${baseUrl}/`;
const normalizedPath = path.startsWith("/") ? path.slice(1) : path;
const url = new URL(normalizedPath, normalizedBase);
Object.entries(params).forEach(([k, v]) => {
if (v !== undefined && v !== null && v !== "") {
url.searchParams.set(k, String(v));
}
});
const apiKey = process.env.BYUL_API_KEY;
if (!apiKey) {
throw new Error("Missing BYUL_API_KEY environment variable");
}
const res = await fetch(url.toString(), {
headers: {
"X-API-Key": apiKey,
},
});
const text = await res.text();
let json: any;
try {
json = text ? JSON.parse(text) : {};
} catch {
json = { raw: text };
}
if (!res.ok) {
const message = json?.message ?? `HTTP ${res.status}`;
const err = new Error(message);
(err as any).status = res.status;
(err as any).response = json;
throw err;
}
return json;
}
export function createServer(options?: ByulMcpOptions) {
const server = new McpServer({
name: "byul_mcp",
version: "0.1.4",
});
// Tool: news_fetch - proxy GET /news
server.registerTool(
"news_fetch",
{
title: "Fetch News",
description: "Fetch latest financial news from Byul REST API with filters",
inputSchema: {
limit: z.number().int().min(1).max(100).optional(),
cursor: z.string().optional(),
sinceId: z.string().optional(),
minImportance: z.number().int().min(1).max(10).optional(),
q: z.string().optional(),
symbol: z.string().optional(),
category: z.string().optional(),
startDate: z.string().optional(),
endDate: z.string().optional(),
},
},
async (args) => {
const data = await callByulApi("/news", {
limit: args.limit,
cursor: args.cursor,
sinceId: args.sinceId,
minImportance: args.minImportance,
q: args.q,
symbol: args.symbol,
category: (args as any).category,
startDate: args.startDate,
endDate: args.endDate,
}, options);
const items = Array.isArray(data?.items) ? data.items : [];
// Fixed output: markdown list without header
const markdown = items.length === 0
? "No articles."
: items.map((it: any) => {
const date = it?.date ?? "";
const title = it?.title ?? "";
const url = it?.url ?? "";
return `- ${date} | ${title} | ${url}`;
}).join("\n");
return { content: [{ type: "text", text: markdown }] };
}
);
return server;
}
export async function runStdio(options?: ByulMcpOptions) {
const server = createServer(options);
const transport = new StdioServerTransport();
await server.connect(transport);
}
