Getting started

Installation

Install the package, pick an entry point, and know which runtimes it runs on.

npm install @unhingged/logit
# or
bun add @unhingged/logit
# or
pnpm add @unhingged/logit

The package has no dependencies and ships ESM and CommonJS builds with TypeScript declarations. It is MIT licensed.

Entry points#

One package, five entry points. The root is isomorphic; the others import Node built-ins and are only loaded where you import them.

Import	What it adds	Runs on
`@unhingged/logit`	The logger, templates, capture, `LogContext`, enrichers, filters, formatters, the console / stream / memory / callback / HTTP / Seq sinks	Node, Bun, Deno, the Next.js edge runtime, browsers
`@unhingged/logit/node`	`fileSink`, `withMachineName`, `withProcessId`, `withProcessInfo`, `interceptConsole`, `closeOnExit` — plus everything in the root	Node, Bun
`@unhingged/logit/next`	`withLogging`, `createOnRequestError`, `requestDiagnostics` — plus everything in the root	Next.js (Node and edge runtimes)
`@unhingged/logit/express`	`requestLogger`, `errorLogger` — plus everything in the root	Node, Bun
`@unhingged/logit/otel`	`otlpHttpSink`, `otelBridgeSink`, `encodeOtlpLogs` — plus everything in the root	Anywhere with `fetch`

Every subpath re-exports the root, so a Node application needs one import:

import { configure, consoleSink, fileSink, closeOnExit, log } from '@unhingged/logit/node';

Runtimes#

Node.js 20.16+ — the ambient context (LogContext) rides on AsyncLocalStorage, found through process.getBuiltinModule without a node: import in the root entry. Node 22 and 24 are the targets; 20.16 is the floor.
Bun and Deno — the same path; both expose AsyncLocalStorage.
Next.js edge runtime — @unhingged/logit/next imports AsyncLocalStorage from node:async_hooks, which the edge runtime provides, and installs it. Use that entry in middleware.ts.
Browsers — the root entry works as is. There is no AsyncLocalStorage, so LogContext falls back to a synchronous stack: properties pushed in a callback are visible inside it, not across await. See Browser.

TypeScript#

Types come with the package. The using keyword for LogContext.push() and Operation needs TypeScript 5.2+ with "lib": ["esnext"] (or "esnext.disposable"); without it, call .dispose() / .abandon() yourself.

import type { LogEvent, Sink, Enricher, Filter, LoggerOptions } from '@unhingged/logit';

What to read next#

The quick start gets a logger writing in a few lines. If you are coming from Serilog, For Serilog users maps every API you know. From pino or winston: migrating from pino, migrating from winston.