winston-logfmt

library1.0.0jsnpmunverified

winston-logfmt 1.0.0 provides a custom logfmt formatter for winston, enabling structured logging in the logfmt key=value format. It ships with TypeScript types and offers a simple `createLogger` function for quick setup, plus a lower-level `logFmtFormat` for custom winston configuration. Currently stable with no active development; best suited for projects already using winston and wanting logfmt output. Alternatives like pino or bunyan offer different trade-offs.

devops

npm install winston-logfmt

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · WINSTON-LOGFMT

winston-logfmt

devopsjavascriptv1.0.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

createLogger

✓ import { createLogger } from 'winston-logfmt'

✗ const createLogger = require('winston-logfmt').createLogger

ESM module; CJS require will not work directly as this is ESM-only.

logFmtFormat

✓ import { logFmtFormat } from 'winston-logfmt'

✗ import logFmtFormat from 'winston-logfmt'

Named export, not default.

LogfmtOptions

✓ import { LogfmtOptions } from 'winston-logfmt' (type import)

✗ const LogfmtOptions = require('winston-logfmt').LogfmtOptions

TypeScript type; use 'import type { LogfmtOptions }' if only using for types.

Shows two ways to create a winston logger with logfmt formatting: using shorthand createLogger and integrating logFmtFormat with winston.createLogger.

import winston from 'winston'; import { createLogger, logFmtFormat } from 'winston-logfmt'; // Simple logger using defaults const logger = createLogger(); logger.info('hello world'); // Custom logger with winston const customLogger = winston.createLogger({ format: logFmtFormat(), transports: [new winston.transports.Console()] }); customLogger.info('custom formatted message');

Debug

Known issues

gotchaImporting via require() fails because the package is ESM-only.

fix

Use `import { createLogger } from 'winston-logfmt'` instead.

affects: 1.0.0

gotchalogFmtFormat is a named export, not default. Attempting default import yields undefined.

fix

Import as `{ logFmtFormat }`.

affects: 1.0.0

gotchaWinston peer dependency must be installed separately.

fix

Run `npm install winston` alongside winston-logfmt.

affects: 1.0.0

Errors

Common errors & fixes

ERR_REQUIRE_ESM: require() of ES Module /path/to/node_modules/winston-logfmt/index.js from /path/to/project/app.js not supported.

Package is ESM-only and cannot be used with require().

fix

Switch to ESM (use `import`) or use dynamic import().

TypeError: logFmtFormat is not a function

Attempted default import of logFmtFormat instead of named import.

fix

Change to `import { logFmtFormat } from 'winston-logfmt'`.

Upgrade

Version history

1.0.0latest on npm

Audit

Dependencies

winstonrequiredPeer dependency for log transport and formatting

Agent activity

6 hits · last 30 days

node

Resources

githubssh://git@github.com/paulrostorp/winston-logfmt ↗

packagewinston-logfmt ↗

homepagehttps://github.com/paulrostorp/winston-logfmt#readme ↗