LibreChat/api/config/winston.js

const path = require('path');
const fs = require('fs');
const winston = require('winston');
require('winston-daily-rotate-file');
const {
  getTenantId,
  getUserId,
  getRequestId,
  SYSTEM_TENANT_ID,
} = require('@librechat/data-schemas');
const {
  redactFormat,
  redactMessage,
  debugTraverse,
  jsonTruncateFormat,
  formatConsoleMeta,
} = require('./parsers');

/**
 * Determine the log directory.
 * Priority:
 * 1. LIBRECHAT_LOG_DIR environment variable (allows user override)
 * 2. /app/logs if running in Docker (bind-mounted with correct permissions)
 * 3. api/logs relative to this file (local development)
 */
const getLogDir = () => {
  if (process.env.LIBRECHAT_LOG_DIR) {
    return process.env.LIBRECHAT_LOG_DIR;
  }

  // Check if running in Docker container (cwd is /app)
  if (process.cwd() === '/app') {
    const dockerLogDir = '/app/logs';
    // Ensure the directory exists
    if (!fs.existsSync(dockerLogDir)) {
      fs.mkdirSync(dockerLogDir, { recursive: true });
    }
    return dockerLogDir;
  }

  // Local development: use api/logs relative to this file
  return path.join(__dirname, '..', 'logs');
};

const logDir = getLogDir();

const { NODE_ENV, DEBUG_LOGGING = true, CONSOLE_JSON = false, DEBUG_CONSOLE = false } = process.env;

const useConsoleJson =
  (typeof CONSOLE_JSON === 'string' && CONSOLE_JSON?.toLowerCase() === 'true') ||
  CONSOLE_JSON === true;

const useDebugConsole =
  (typeof DEBUG_CONSOLE === 'string' && DEBUG_CONSOLE?.toLowerCase() === 'true') ||
  DEBUG_CONSOLE === true;

const useDebugLogging =
  (typeof DEBUG_LOGGING === 'string' && DEBUG_LOGGING?.toLowerCase() === 'true') ||
  DEBUG_LOGGING === true;

const levels = {
  error: 0,
  warn: 1,
  info: 2,
  http: 3,
  verbose: 4,
  debug: 5,
  activity: 6,
  silly: 7,
};

const LOG_CONTEXT_KEYS = ['tenantId', 'userId', 'requestId'];

const getLogTenantId = () => {
  const tenantId = getTenantId();
  return tenantId === SYSTEM_TENANT_ID ? undefined : tenantId;
};

const requestContextFormat = winston.format((info) => {
  if (info.tenantId === SYSTEM_TENANT_ID) {
    delete info.tenantId;
  }
  const context = {
    tenantId: getLogTenantId(),
    userId: getUserId(),
    requestId: getRequestId(),
  };
  LOG_CONTEXT_KEYS.forEach((key) => {
    if (context[key] && info[key] == null) {
      info[key] = context[key];
    }
  });
  return info;
});

const formatRequestContext = (info) => {
  const context = {};
  LOG_CONTEXT_KEYS.forEach((key) => {
    const value = info[key];
    if (key === 'tenantId' && value === SYSTEM_TENANT_ID) {
      return;
    }
    if (typeof value === 'string' && value) {
      context[key] = value;
    }
  });
  return Object.keys(context).length > 0 ? JSON.stringify(context) : '';
};

winston.addColors({
  info: 'green', // fontStyle color
  warn: 'italic yellow',
  error: 'red',
  debug: 'blue',
});

const level = () => {
  const env = NODE_ENV || 'development';
  const isDevelopment = env === 'development';
  return isDevelopment ? 'debug' : 'warn';
};

const fileFormat = winston.format.combine(
  redactFormat(),
  winston.format.timestamp({ format: () => new Date().toISOString() }),
  winston.format.errors({ stack: true }),
  winston.format.splat(),
  requestContextFormat(),
  // redactErrors(),
);

const transports = [
  new winston.transports.DailyRotateFile({
    level: 'error',
    filename: `${logDir}/error-%DATE%.log`,
    datePattern: 'YYYY-MM-DD',
    zippedArchive: true,
    maxSize: '20m',
    maxFiles: '14d',
    format: fileFormat,
  }),
];

if (useDebugLogging) {
  transports.push(
    new winston.transports.DailyRotateFile({
      level: 'debug',
      filename: `${logDir}/debug-%DATE%.log`,
      datePattern: 'YYYY-MM-DD',
      zippedArchive: true,
      maxSize: '20m',
      maxFiles: '14d',
      format: winston.format.combine(fileFormat, debugTraverse),
    }),
  );
}

const consoleFormat = winston.format.combine(
  redactFormat(),
  requestContextFormat(),
  winston.format.colorize({ all: true }),
  winston.format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }),
  // redactErrors(),
  winston.format.printf((info) => {
    const base = `${info.timestamp} ${info.level}: ${info.message}`;
    const isErrorOrWarn = info.level.includes('error') || info.level.includes('warn');
    const metaTrailer = isErrorOrWarn ? formatConsoleMeta(info) : formatRequestContext(info);
    const line = metaTrailer ? `${base} ${metaTrailer}` : base;
    return isErrorOrWarn ? redactMessage(line) : line;
  }),
);

// Determine console log level
let consoleLogLevel = 'info';
if (useDebugConsole) {
  consoleLogLevel = 'debug';
}

if (useDebugConsole) {
  transports.push(
    new winston.transports.Console({
      level: consoleLogLevel,
      format: useConsoleJson
        ? winston.format.combine(fileFormat, jsonTruncateFormat(), winston.format.json())
        : winston.format.combine(fileFormat, debugTraverse),
    }),
  );
} else if (useConsoleJson) {
  transports.push(
    new winston.transports.Console({
      level: consoleLogLevel,
      format: winston.format.combine(fileFormat, jsonTruncateFormat(), winston.format.json()),
    }),
  );
} else {
  transports.push(
    new winston.transports.Console({
      level: consoleLogLevel,
      format: consoleFormat,
    }),
  );
}

const logger = winston.createLogger({
  level: level(),
  levels,
  transports,
});

module.exports = logger;