mcp-framework/dist/core/Logger.js

Framework for building Model Context Protocol (MCP) servers in Typescript

import { createWriteStream } from "fs";
import { join } from "path";
import { mkdir } from "fs/promises";
export class Logger {
    static instance;
    logStream = null;
    logFilePath = '';
    logToFile = false;
    constructor() {
        this.logToFile = process.env.MCP_ENABLE_FILE_LOGGING === 'true';
        if (this.logToFile) {
            const timestamp = new Date().toISOString().replace(/[:.]/g, "-");
            const logDir = process.env.MCP_LOG_DIRECTORY || "logs";
            this.initFileLogging(logDir, timestamp);
        }
        process.on("exit", () => this.close());
        process.on("SIGINT", () => this.close());
        process.on("SIGTERM", () => this.close());
    }
    async initFileLogging(logDir, timestamp) {
        try {
            await mkdir(logDir, { recursive: true });
            this.logFilePath = join(logDir, `mcp-server-${timestamp}.log`);
            this.logStream = createWriteStream(this.logFilePath, { flags: "a" });
            this.info(`File logging enabled, writing to: ${this.logFilePath}`);
        }
        catch (err) {
            process.stderr.write(`Failed to initialize file logging: ${err}\n`);
            this.logToFile = false;
        }
    }
    static getInstance() {
        if (!Logger.instance) {
            Logger.instance = new Logger();
        }
        return Logger.instance;
    }
    getTimestamp() {
        return new Date().toISOString();
    }
    formatMessage(level, message) {
        return `[${this.getTimestamp()}] [${level}] ${message}\n`;
    }
    info(message) {
        const formattedMessage = this.formatMessage("INFO", message);
        if (this.logToFile && this.logStream) {
            this.logStream.write(formattedMessage);
        }
        process.stderr.write(formattedMessage);
    }
    log(message) {
        this.info(message);
    }
    error(message) {
        const formattedMessage = this.formatMessage("ERROR", message);
        if (this.logToFile && this.logStream) {
            this.logStream.write(formattedMessage);
        }
        process.stderr.write(formattedMessage);
    }
    warn(message) {
        const formattedMessage = this.formatMessage("WARN", message);
        if (this.logToFile && this.logStream) {
            this.logStream.write(formattedMessage);
        }
        process.stderr.write(formattedMessage);
    }
    debug(message) {
        const formattedMessage = this.formatMessage("DEBUG", message);
        if (this.logToFile && this.logStream) {
            this.logStream.write(formattedMessage);
        }
        if (process.env.MCP_DEBUG_CONSOLE === 'true') {
            process.stderr.write(formattedMessage);
        }
    }
    close() {
        if (this.logStream) {
            this.logStream.end();
            this.logStream = null;
        }
    }
    getLogPath() {
        return this.logFilePath;
    }
    isFileLoggingEnabled() {
        return this.logToFile;
    }
}
export const logger = Logger.getInstance();