@voltagent/logger

Provider-agnostic logging system for VoltAgent with built-in Pino support.

🚀 Quick Start

npm install @voltagent/logger

Usage

Using Pino Logger (Built-in)

import { createPinoLogger } from "@voltagent/logger";

// Create a Pino logger instance
const logger = createPinoLogger({
  name: "my-app",
  level: process.env.LOG_LEVEL || "info",
  format: "pretty", // "json" or "pretty"
  redact: ["password", "token", "apiKey"], // Fields to redact
  bufferSize: 1000, // Log buffer size
});

// Use the logger
logger.info("Application started");
logger.debug({ userId: "123" }, "User logged in");
logger.error({ err: error }, "An error occurred");

// Create child loggers with context
const requestLogger = logger.child({ requestId: "abc123" });
requestLogger.info("Processing request");

Creating Custom Logger Providers

The logger system is designed to be provider-agnostic. You can implement your own logger provider:

import { LoggerProvider, LoggerWithProvider } from "@voltagent/logger";
import type { Logger, LoggerOptions, LogBuffer } from "@voltagent/logger";

export class WinstonLoggerProvider implements LoggerProvider {
  name = "winston";

  createLogger(options?: LoggerOptions): LoggerWithProvider {
    // Implement Winston logger creation
  }

  createChildLogger(parent: Logger, bindings: Record<string, any>): Logger {
    // Implement child logger creation
  }

  getLogBuffer(): LogBuffer {
    // Return log buffer implementation
  }
}

// Use custom provider
import { setGlobalLoggerProvider } from "@voltagent/logger";
setGlobalLoggerProvider(new WinstonLoggerProvider());

Features

• Provider-agnostic: Core types don't depend on any specific logger implementation
• Built-in Pino support: High-performance logging with Pino
• Log buffering: In-memory buffer for recent logs
• Child loggers: Create contextual loggers with additional metadata
• Pretty printing: Human-readable logs in development
• Log redaction: Automatically redact sensitive fields
• Extensible: Easy to add new logger providers

Configuration

Environment Variables

• LOG_LEVEL or VOLTAGENT_LOG_LEVEL: Set the log level (trace, debug, info, warn, error, fatal)
• VOLTAGENT_LOG_FORMAT: Set format to "json" or "pretty"
• VOLTAGENT_LOG_REDACT: Comma-separated list of additional fields to redact
• VOLTAGENT_LOG_BUFFER_SIZE: Maximum number of logs to keep in buffer (default: 1000)

📄 License

MIT License - see LICENSE file for details.