Asset Price MCP Server

import { z } from "zod"; import { PriceService, AssetSymbol, AssetPrice, AssetSymbolSchema } from "../types.js"; import { fetchJson } from "../utils.js"; import { apiCache } from "../cache.js"; const BASE_URL = "https://api.gold-api.com"; // Gold API returns slightly different structure for symbols sometimes, but let's stick to the schema const GoldApiSymbolSchema = z.array(AssetSymbolSchema); // Gold API price response matches our schema closely const GoldApiPriceSchema = z.object({ name: z.string(), price: z.number(), symbol: z.string(), updatedAt: z.string(), updatedAtReadable: z.string().optional(), }); export class GoldApiService implements PriceService { getName(): string { return "GoldAPI"; } async getSupportedAssets(): Promise<AssetSymbol[]> { const cacheKey = `${BASE_URL}/symbols`; const cached = apiCache.get<AssetSymbol[]>(cacheKey); if (cached) return cached; const symbols = await fetchJson(cacheKey, GoldApiSymbolSchema); if (symbols) { apiCache.set(cacheKey, symbols); return symbols; } return []; } async getPrice(symbol: string, currency: string = 'USD'): Promise<AssetPrice | null> { // Gold API mostly supports USD, and currency conversion might not be supported directly in this endpoint // We will ignore currency for now or only support USD if (currency !== 'USD') { // TODO: Could implement manual conversion if needed } const url = `${BASE_URL}/price/${symbol}`; const cacheKey = `${url}?currency=${currency}`; const cached = apiCache.get<AssetPrice>(cacheKey); if (cached) return cached; const rawData = await fetchJson(url, GoldApiPriceSchema); if (rawData) { const priceData: AssetPrice = { ...rawData, currency: 'USD', // Gold API prices are in USD by default }; apiCache.set(cacheKey, priceData); return priceData; } return null; } async getPrices(symbols: string[], currency: string = 'USD'): Promise<AssetPrice[]> { const promises = symbols.map(s => this.getPrice(s, currency)); const results = await Promise.all(promises); return results.filter((p): p is AssetPrice => p !== null); } }