Registry / observability / koa-logger

koa-logger

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library4.0.0jsnpmunverified

Koa-logger is a development-style logging middleware for Koa.js applications, providing colorful, concise HTTP request and response logging to the console. The current stable version, 4.0.0, was released after a period of lower activity, signaling a revival of the project and bringing support for Koa v3 and Node.js versions 18 and higher. It outputs request method, URL, response status, duration, and content length, often formatted with ANSI colors for readability. A key differentiator is its customizable `transporter` option, which allows developers to redirect log output to alternative pipes or logging systems, rather than just `process.stdout`. While primarily a CommonJS package, its updates ensure compatibility with modern Node.js environments and Koa framework versions.

observabilityweb-framework
npm install koa-logger
github ↗package ↗
INSTALL
IMPORT
SIG · KOA-LOGGER
K
koa-logger
observabilityjavascriptv4.0.0
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.

logger
✓ const logger = require('koa-logger')
✗ import logger from 'koa-logger'
Koa-logger v4.x is primarily a CommonJS package. While Node.js 18+ supports ESM, direct 'import' statements for this package may not work as expected without specific transpilation or Node.js configurations. Use 'require' for direct CommonJS usage.
logger
✓ import logger from 'koa-logger';
✗ import { logger } from 'koa-logger';
While primarily CommonJS, if you are using an environment that transpiles CommonJS to ESM or are using Node.js's CJS-ESM interop, `import logger from 'koa-logger'` would be the correct pattern for its default export. `import { logger } from 'koa-logger'` is incorrect as it's not a named export.

This quickstart demonstrates how to initialize a basic Koa application and integrate `koa-logger` as the primary logging middleware, showing its effect on console output for various HTTP requests.

const Koa = require('koa'); const logger = require('koa-logger'); const app = new Koa(); // Use koa-logger middleware as early as possible to wrap all subsequent middleware app.use(logger()); // Example middleware to handle requests app.use(async (ctx, next) => { if (ctx.path === '/') { ctx.body = 'Hello, Koa-logger!'; } else if (ctx.path === '/users') { ctx.body = [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }]; } else { ctx.status = 404; ctx.body = 'Not Found'; } await next(); // Pass control to subsequent middleware }); const port = process.env.PORT || 3000; app.listen(port, () => { console.log(`Koa server running on http://localhost:${port}`); }); // To run this: // 1. npm install koa koa-logger // 2. node your-file-name.js // 3. Open http://localhost:3000 or http://localhost:3000/users in your browser.
Debug
Known issues
breakingKoa-logger v4.0.0 dropped support for Node.js versions older than 10. Users on Node.js < 18 (the recommended version for v4) should upgrade their Node.js runtime or use an older version of koa-logger.
fix
Upgrade Node.js to version 18 or higher. If unable to upgrade Node.js, consider using koa-logger v3.x or earlier.
affects: >=4.0.0
breakingKoa-logger v4.0.0 explicitly adds support for Koa v3. While it might work with Koa v2, compatibility issues may arise due to potential API changes in Koa itself. It's recommended to align Koa and koa-logger versions.
fix
Ensure your Koa application is running Koa v3.x when using koa-logger v4.x. If using Koa v2.x, consider pinning koa-logger to an earlier major version (e.g., v3.x).
affects: >=4.0.0
gotchaFor comprehensive logging, koa-logger should be applied as early as possible in the middleware stack (e.g., `app.use(logger())` near the top). Placing it after other middleware might result in those preceding middleware's operations not being fully captured in the log.
fix
Always place `app.use(logger())` as one of the first middleware in your Koa application setup to ensure it 'wraps' all subsequent middleware and accurately logs all request/response cycles.
affects: >=1.0.0
Errors
Common errors & fixes
TypeError: app.use is not a function
Koa is not correctly initialized or imported, or 'app' is not a Koa application instance.
fix
Ensure 'koa' is installed (`npm install koa`) and you are creating a Koa application instance with `const Koa = require('koa'); const app = new Koa();`.
TypeError: koa_logger_1.default is not a function
Attempting to use an ESM default import syntax (`import logger from 'koa-logger';`) for a package that is primarily CommonJS in an environment where direct CJS-ESM interop is not configured or fails.
fix
Use the CommonJS require syntax: `const logger = require('koa-logger');`. If you must use ESM, ensure your build setup correctly handles CJS module imports.
ReferenceError: logger is not defined
The `koa-logger` middleware was not imported or assigned to the `logger` variable before being used.
fix
Add `const logger = require('koa-logger');` at the top of your file to import the middleware.
Upgrade
Version history
4.0.0latest on npm
Audit
Dependencies
koarequiredKoa-logger is a middleware for Koa.js applications and requires Koa to function. It is an implied peer dependency.
Agent activity
23 hits · last 30 days
node
20
OpenAI (training)
2
Resources
githubhttps://github.com/koajs/logger ↗
packagehttps://www.npmjs.com/package/koa-logger ↗
koa-logger — npm install koa-logger · libregistry