Presearch MCP Server

import axios from "axios"; import { loadConfig } from "./config.js"; import logger from "./logger.js"; /** * Enhanced API Client with monitoring, retries, and circuit breaking */ class ApiClient { constructor() { this.config = loadConfig(); this.axiosInstance = axios.create({ baseURL: this.config.baseUrl, timeout: this.config.timeout, headers: { "X-Source": "presearch-mcp-server", Accept: "application/json", }, }); this.rateLimit = { remaining: 60, reset: Date.now() + 60000, total: 60, }; // Request interceptor for auth and logging this.axiosInstance.interceptors.request.use( (config) => { // Dynamic config loading to pick up runtime changes const currentConfig = loadConfig(); if (currentConfig.apiKey) { config.headers["Authorization"] = `Bearer ${currentConfig.apiKey}`; } logger.debug(`API Request: ${config.method?.toUpperCase()} ${config.url}`, { params: config.params, }); return config; }, (error) => { logger.error("API Request Error", { error: error.message }); return Promise.reject(error); }, ); // Response interceptor for rate limiting and logging this.axiosInstance.interceptors.response.use( (response) => { this.updateRateLimit(response.headers); logger.debug(`API Response: ${response.status}`, { url: response.config.url, dataLength: JSON.stringify(response.data).length, }); return response; }, async (error) => { this.updateRateLimit(error.response?.headers); if (error.response) { logger.error( `API Error: ${error.response.status} ${error.response.statusText}`, { data: error.response.data, url: error.config?.url, }, ); // Enhanced handling for 402 Payment Required if (error.response.status === 402) { const paymentError = new Error( "PRESEARCH API PAYMENT REQUIRED: Your account has insufficient credits. " + "Please visit https://presearch.com/account/tokens to top up your account or check your plan." ); paymentError.name = "PaymentRequiredError"; paymentError.status = 402; return Promise.reject(paymentError); } } else { logger.error("Network Error", { error: error.message }); } // Implement simple exponential backoff for 429 and 5xx const config = error.config; if ( config && !config.__isRetryRequest && (error.response?.status === 429 || error.response?.status >= 500) ) { config.__isRetryRequest = true; config.__retryCount = config.__retryCount || 0; if (config.__retryCount < this.config.retries) { config.__retryCount++; const delay = Math.pow(2, config.__retryCount) * 1000; logger.info( `Retrying request (${config.__retryCount}/${this.config.retries}) in ${delay}ms...`, ); await new Promise((resolve) => setTimeout(resolve, delay)); return this.axiosInstance(config); } } return Promise.reject(error); }, ); } /** * Update rate limit tracking from response headers */ updateRateLimit(headers) { if (!headers) return; if (headers["x-ratelimit-remaining"]) { this.rateLimit.remaining = parseInt(headers["x-ratelimit-remaining"], 10); } if (headers["x-ratelimit-reset"]) { this.rateLimit.reset = parseInt(headers["x-ratelimit-reset"], 10) * 1000; } if (headers["x-ratelimit-limit"]) { this.rateLimit.total = parseInt(headers["x-ratelimit-limit"], 10); } } /** * Check if we are rate limited locally before making a request */ checkRateLimit() { if (this.rateLimit.remaining <= 0 && Date.now() < this.rateLimit.reset) { const waitTime = Math.ceil((this.rateLimit.reset - Date.now()) / 1000); throw new Error( `Rate limit exceeded. Please try again in ${waitTime} seconds.`, ); } } /** * Make a GET request */ async get(url, config = {}) { this.checkRateLimit(); return this.axiosInstance.get(url, config); } /** * Make a POST request */ async post(url, data, config = {}) { this.checkRateLimit(); return this.axiosInstance.post(url, data, config); } /** * Get current rate limit stats */ getRateLimitStats() { return { ...this.rateLimit, resetDate: new Date(this.rateLimit.reset).toISOString(), }; } } export const apiClient = new ApiClient();