logger.ts#

This module provides a single, globally shared logger instance for the entire application. It uses the pino library, which is a high-performance, JSON-based logger.

Configuration#

The pino logger is configured with the following options:

• level: The minimum log level to output.

  • It is configured from the LOG_LEVEL environment variable.
  • If LOG_LEVEL is not set, it defaults to "info". This means logger.debug() messages will be ignored unless the level is explicitly set to "debug".

• formatters.level: This custom formatter ensures that the log level is output as a JSON property (e.g., {"level": "info"}).

• timestamp: This custom function formats the timestamp as an ISO 8601 string within a JSON property (e.g., ,"time":"2025-11-12T12:00:00.000Z").

• base: undefined: This option removes the default pid (process ID) and hostname properties from the log output, keeping the logs cleaner.

logger Instance#

• export const logger = pino(...): This creates and exports the singleton logger instance that all other modules import and use.

Example Usage#

import { logger } from "./logger.js";

logger.info({ process: "MAIN", status: "starting" }, "Application is starting up");
// Output: {"level":"info","time":"...","process":"MAIN","status":"starting","msg":"Application is starting up"}

logger.debug({ did: "did:plc:123" }, "Checking user");
// Output (only if LOG_LEVEL=debug): {"level":"debug","time":"...","did":"did:plc:123","msg":"Checking user"}

logger.error({ error: new Error("Something failed") }, "An error occurred");
// Output: {"level":"error","time":"...","error":{...},"msg":"An error occurred"}

Dependencies#

• pino: The underlying logging library.