@access-mcp/shared/dist/logger.js

Shared utilities for ACCESS-CI MCP servers

/**
 * Structured logger for ACCESS-CI MCP servers.
 *
 * This logger writes to stderr to avoid interfering with MCP's JSON-RPC
 * communication on stdout. It supports log levels that can be controlled
 * via the LOG_LEVEL environment variable.
 *
 * Log levels (in order of severity):
 * - error: Always shown, for critical errors
 * - warn: Warnings that don't prevent operation
 * - info: Important informational messages
 * - debug: Detailed debugging information (disabled by default)
 *
 * Usage:
 *   import { createLogger } from "@access-mcp/shared";
 *   const logger = createLogger("my-server");
 *   logger.info("Server started");
 *   logger.error("Failed to connect", { url: "http://..." });
 */
const LOG_LEVELS = {
    error: 0,
    warn: 1,
    info: 2,
    debug: 3,
};
function getLogLevel() {
    const level = process.env.LOG_LEVEL?.toLowerCase();
    if (level && level in LOG_LEVELS) {
        return level;
    }
    // Default to 'warn' for production (errors and warnings only)
    return "warn";
}
function shouldLog(level) {
    const currentLevel = getLogLevel();
    return LOG_LEVELS[level] <= LOG_LEVELS[currentLevel];
}
function formatMessage(serverName, level, message, context) {
    const timestamp = new Date().toISOString();
    const contextStr = context ? ` ${JSON.stringify(context)}` : "";
    return `[${timestamp}] [${serverName}] [${level.toUpperCase()}] ${message}${contextStr}`;
}
/**
 * Create a logger instance for a specific server.
 *
 * @param serverName - The name of the server (e.g., "access-mcp-events")
 * @returns A logger instance with error, warn, info, and debug methods
 */
export function createLogger(serverName) {
    return {
        error: (message, context) => {
            if (shouldLog("error")) {
                console.error(formatMessage(serverName, "error", message, context));
            }
        },
        warn: (message, context) => {
            if (shouldLog("warn")) {
                console.error(formatMessage(serverName, "warn", message, context));
            }
        },
        info: (message, context) => {
            if (shouldLog("info")) {
                console.error(formatMessage(serverName, "info", message, context));
            }
        },
        debug: (message, context) => {
            if (shouldLog("debug")) {
                console.error(formatMessage(serverName, "debug", message, context));
            }
        },
    };
}
/**
 * A no-op logger that silently discards all log messages.
 * Useful for testing or when logging should be completely disabled.
 */
export const silentLogger = {
    error: () => { },
    warn: () => { },
    info: () => { },
    debug: () => { },
};