Console Transport

The console transport prints each entry to the terminal. warn and error go to stderr, everything else goes to stdout. It writes synchronously, so it never allocates a promise on the hot path.

Import ConsoleTransport from logixia/transports if you need the class. Most of the time you just set transports.console.

Quick start

import { createLogger } from 'logixia';

const logger = createLogger({
  appName: 'api',
  transports: {
    console: { format: 'text', colorize: true },
  },
});

await logger.info('Server started', { port: 3000 });

Text output looks like this: a gray timestamp, the level padded to 5 characters, the context in brackets, the trace ID in parentheses, the message, then the payload as JSON.

JSON output

Set format: 'json' for one compact JSON object per line, which is what log collectors in containers expect.

import { createLogger } from 'logixia';

const logger = createLogger({
  appName: 'api',
  environment: 'production',
  transports: {
    console: { format: 'json' },
  },
});

await logger.info('Order placed', { orderId: 'o_1' });

The JSON object has timestamp, level, message, context, traceId, appName and environment, followed by your payload keys. If a payload key clashes with one of those names, logixia keeps the core field and stores your value under a data_ prefix, for example data_level.

Options

Option	Type	Default	Description
format	'json' | 'text'	'text'	Pretty text or one JSON object per line.
colorize	boolean	on	ANSI colors in text mode. Set false to turn them off.
timestamp	boolean	on	Include the ISO timestamp. Set false to drop it.
levelColors	Record<string, string>	none	Level name to color name. See below.
filter	(entry) => boolean	none	Return false to skip an entry on this transport.
level	string	none	Declared in the type, but see the warning below.

WARNING

The console transport does not apply level. Setting transports.console.level has no effect today. To change what reaches the console, set the logger's global levelOptions.level, or use filter:

import { createLogger } from 'logixia';

const logger = createLogger({
  appName: 'api',
  transports: {
    console: { filter: (entry) => entry.level !== 'debug' },
  },
});

Level colors

Built-in colors are error red, warn and warning yellow, info green, debug blue, trace magenta and verbose cyan. Anything else is gray.

For custom levels, set levelOptions.colors on the logger. logixia passes that map to the console transport as levelColors for you.

import { createLogger } from 'logixia';

const logger = createLogger({
  appName: 'api',
  levelOptions: {
    level: 'info',
    levels: { error: 0, warn: 1, info: 2, kafka: 2 },
    colors: { kafka: 'magenta' },
  },
  transports: { console: {} },
});

await logger.kafka('Consumer joined group');

Color names are black, red, green, yellow, blue, magenta, cyan, white, gray, grey and the bright variants (brightred, brightgreen, and so on).

Safe by default

In text mode, control characters are stripped from the level, context, trace ID and message, so a hostile string cannot inject ANSI escapes or fake log lines into your terminal. Payloads are serialized with a cycle-safe JSON.stringify, which already escapes control characters.

Related

• Configuration for logger-level format and level options
• Log levels for custom levels and colors
• File transport to also keep logs on disk