import pino from 'pino';
import type { Logger } from 'pino';
/**
* Logger configuration interface
*/
interface LoggerConfig {
level?: 'trace' | 'debug' | 'info' | 'warn' | 'error' | 'fatal';
isDevelopment?: boolean;
redact?: string[];
}
/**
* Create a structured logger instance
*/
export function createLogger(config: LoggerConfig = {}): Logger {
const { level = 'info', isDevelopment = false, redact = [] } = config;
const baseRedact = [
// Security: Always redact these fields
'apiToken',
'token',
'password',
'secret',
'key',
'authorization',
'cookie',
'session',
// Add custom redact fields
...redact,
];
return pino(
{
level,
redact: {
paths: baseRedact,
censor: '[REDACTED]',
},
timestamp: pino.stdTimeFunctions.isoTime,
formatters: {
level: (label) => ({ level: label }),
},
...(isDevelopment && {
transport: {
target: 'pino-pretty',
options: {
colorize: true,
ignore: 'pid,hostname',
translateTime: 'SYS:standard',
},
},
}),
},
// IMPORTANT: Write logs to stderr to avoid interfering with JSON-RPC on stdout
process.stderr
);
}
/**
* Default logger instance
*/
// Determine effective log level with safe production default.
// Priority: explicit LOG_LEVEL env > NODE_ENV-based default
const envLevel = process.env['LOG_LEVEL'] as LoggerConfig['level'] | undefined;
const nodeEnv = process.env['NODE_ENV'];
// Treat anything other than explicit 'development' as production-like (including unset)
const effectiveLevel: LoggerConfig['level'] = envLevel ?? (nodeEnv === 'development' ? 'info' : 'error');
export const logger = createLogger({
level: effectiveLevel,
// Development mode only when explicitly set
isDevelopment: nodeEnv === 'development',
});
/**
* Log levels for conditional logging
*/
export const LOG_LEVELS = {
TRACE: 10,
DEBUG: 20,
INFO: 30,
WARN: 40,
ERROR: 50,
FATAL: 60,
} as const;
