Registry / web-framework / koa-pino-logger

koa-pino-logger

library5.0.0jsnpmunverified

koa-pino-logger is a high-performance Koa middleware for integrating the Pino JSON logger into web applications. Currently at version 5.0.0, it offers rapid, structured logging with minimal overhead, differentiating itself from alternatives like koa-bunyan-logger, koa-logger, and koa-morgan through its speed, native JSON output, support for arbitrary data, and avoidance of `eval` for performance. Its release cadence is sporadic, typically aligning with major updates to the underlying `pino` logger or the `Koa` framework. It's particularly favored for production environments where log processing efficiency and structured output are critical for observability platforms.

web-framework observability

npm install koa-pino-logger

github ↗package ↗

INSTALL

IMPORT

SIG · KOA-PINO-LOGGER

koa-pino-logger

web-frameworkjavascriptv5.0.0

Install

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Import

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Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

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

koaPinoLogger

✓ import koaPinoLogger from 'koa-pino-logger'

✗ const koaPinoLogger = require('koa-pino-logger').default

While the example uses `require()`, modern Koa applications often use ESM. The default export is the middleware function.

Koa

✓ import Koa from 'koa'

✗ const Koa = require('koa')

CommonJS `require('koa')` is still prevalent in older projects, but `import Koa from 'koa'` is standard for ESM.

Middleware

✓ import { Middleware } from 'koa'

✗ import { KoaMiddleware } from 'koa'

Types for Koa's middleware are generally imported from 'koa' or '@types/koa'. koa-pino-logger extends `ctx.log`.

This example demonstrates how to set up `koa-pino-logger` in a basic Koa application to automatically log requests and allows accessing the logger instance on `ctx.log` for custom logging within middleware.

import Koa from 'koa'; import pinoLogger from 'koa-pino-logger'; const app = new Koa(); // Initialize the logger middleware const loggerMiddleware = pinoLogger(); app.use(loggerMiddleware); // Access the logger via ctx.log within downstream middleware app.use((ctx) => { ctx.log.info({ user: 'example-user' }, 'Request processed for user'); ctx.body = 'Hello world with logging'; }); const PORT = process.env.PORT ?? 3000; app.listen(PORT, () => { console.log(`Server listening on port ${PORT}`); console.log('Test with: curl http://localhost:3000 | pino'); });

Debug

Known issues

breakingVersion 5.0.0 drops support for Node.js 12 and adds support for Node.js 18. Ensure your environment meets this new requirement.

fix

Upgrade your Node.js runtime to version 18 or higher.

affects: >=5.0.0

breakingVersion 4.0.0 updated to use `pino@7`. This may introduce breaking changes or deprecations inherited from Pino itself, particularly concerning how transports work with `pino.transport` and handling of `pino.final()`.

fix

Review Pino v7 release notes and adapt any custom Pino configurations, especially around transports and exit handling.

affects: >=4.0.0

gotchakoa-pino-logger is designed for Koa v2 and above. Using it with Koa v1 (which uses generator functions) will lead to compatibility issues.

fix

Ensure your Koa application is running on Koa v2 or later. If on Koa v1, refer to the `v1 readme` on the package's GitHub or migrate your Koa application.

affects: >=2.0.0

gotchaWhen logging thrown errors, Koa's default error handling prints to `console.error`. To prevent duplicate output with `koa-pino-logger`, set `app.silent = true` on your Koa application instance.

fix

Add `app.silent = true;` after `const app = new Koa();` to suppress Koa's default error logging.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: ctx.log is undefined

The `koa-pino-logger` middleware was not applied to the Koa application, or `ctx.log` is being accessed before the middleware has executed for a given request.

fix

Ensure `app.use(logger());` is called early in your Koa application's middleware chain, before any middleware that attempts to use `ctx.log`.

Error: Cannot find module 'koa'

The `koa` package, a peer dependency, is not installed in the project.

fix

Install Koa: `npm install koa` or `yarn add koa`.

Error: Cannot find module 'pino'

The `pino` package, a peer dependency, is not installed, or `koa-pino-logger`'s internal dependency resolution for `pino` failed.

fix

Install Pino: `npm install pino` or `yarn add pino`. Ensure it's available for `koa-pino-logger` to use.

TypeError: app.use is not a function

Attempting to use `app.use` on an object that is not a Koa application instance, or `Koa` was imported incorrectly.

fix

Verify that `app` is an instance of `Koa` (e.g., `const app = new Koa();`) and that `koa` is correctly imported (e.g., `import Koa from 'koa';` or `const Koa = require('koa');`).

Upgrade

Version history

5.0.0latest on npm

Audit

Dependencies

koarequiredRuntime dependency as it's a Koa middleware. koa-pino-logger v5 is compatible with Koa v2+.

pinorequiredCore logging library used by the middleware. Users are expected to have pino installed, especially for CLI tools like `pino-pretty`.

Agent activity

21 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/pinojs/koa-pino-logger ↗

packagehttps://www.npmjs.com/package/koa-pino-logger ↗