{"id":17792,"library":"menoetius","title":"Prometheus Node.js Middleware","description":"Menoetius is a Node.js middleware designed to automatically instrument web applications and expose Prometheus-compatible metrics. It enables developers to easily gather response duration metrics (summary and histogram types) and fundamental Node.js system metrics, all accessible via a configurable `/metrics` endpoint. The library supports integration with popular HTTP frameworks like `http`, `express`, `hapi`, and `restify`. However, the package is currently at a very early version (0.0.3), was likely published many years ago, and appears to be abandoned, with no discernible updates or active development. It relies on `prom-client` for metric collection, which has evolved significantly since Menoetius's last release. Due to its unmaintained status, it may lack compatibility with modern Node.js versions and up-to-date Prometheus client best practices, making it unsuitable for new projects.","status":"abandoned","version":"0.0.3","language":"javascript","source_language":"en","source_url":"https://github.com/achingbrain/menoetius","tags":["javascript","prometheus","metrics","express","restify"],"install":[{"cmd":"npm install menoetius","lang":"bash","label":"npm"},{"cmd":"yarn add menoetius","lang":"bash","label":"yarn"},{"cmd":"pnpm add menoetius","lang":"bash","label":"pnpm"}],"dependencies":[{"reason":"Used internally to collect and expose system metrics and as the underlying Prometheus client library. Menoetius likely depends on a very old version, which may lead to compatibility issues with current prom-client versions or Prometheus standards.","package":"prom-client","optional":false}],"imports":[{"note":"Menoetius was released as a CommonJS module (Node.js >=4.0.0). Attempting to import it using ES Modules syntax (e.g., `import`) will likely result in runtime errors in modern Node.js environments without proper transpilation or wrapper.","wrong":"import menoetius from 'menoetius';","symbol":"menoetius","correct":"const menoetius = require('menoetius');"},{"note":"The `instrument` function is exposed as a method on the default export object. It's not a named export and should be called directly on the imported `menoetius` object.","wrong":"const { instrument } = require('menoetius'); // or instrument(app);","symbol":"instrument","correct":"menoetius.instrument(app);"}],"quickstart":{"code":"const express = require('express');\nconst http = require('http');\nconst menoetius = require('menoetius');\n\nconst app = express();\n\n// Instrument the Express application\nmenoetius.instrument(app, { url: '/metrics-data' });\n\napp.get('/', (req, res) => {\n  // Simulate some work\n  const delay = Math.random() * 200; // 0-200ms\n  setTimeout(() => {\n    res.status(200).send('Hello from Menoetius-instrumented Express!');\n  }, delay);\n});\n\napp.get('/slow', (req, res) => {\n  // Simulate a slower response\n  const delay = Math.random() * 1500 + 500; // 500-2000ms\n  setTimeout(() => {\n    res.status(200).send('This was a bit slower, check metrics!');\n  }, delay);\n});\n\napp.get('/error', (req, res) => {\n  // Simulate an error response\n  res.status(500).send('An internal server error occurred!');\n});\n\nconst PORT = 3000;\napp.listen(PORT, () => {\n  console.log(`Express server listening on port ${PORT}`);\n  console.log(`Metrics available at http://localhost:${PORT}/metrics-data`);\n  console.log('Try hitting /, /slow, and /error endpoints.');\n});","lang":"javascript","description":"Demonstrates how to integrate Menoetius with an Express.js application to automatically expose request duration and system metrics on a custom `/metrics-data` endpoint."},"warnings":[{"fix":"Avoid using Menoetius for new projects. For existing applications, consider migrating to a actively maintained Prometheus client library like `prom-client` directly or another up-to-date middleware.","message":"The Menoetius package (version 0.0.3) is extremely old and has been abandoned for several years. It is highly unlikely to be compatible with modern Node.js versions (e.g., Node.js 14+), newer Express.js versions, or the latest `prom-client` APIs. Expect significant breaking changes and runtime errors.","severity":"breaking","affected_versions":">=0.0.3"},{"fix":"Be aware of the path aggregation and ensure it meets your monitoring requirements. If granular path metrics are critical, this library is not suitable.","message":"Menoetius uses an outdated approach to normalize request paths for labels (e.g., `/users/freddie` becomes `/users/`). While this prevents high cardinality, it might mask granular performance issues at specific user or resource endpoints. Modern Prometheus clients often allow more configurable path labeling strategies.","severity":"gotcha","affected_versions":">=0.0.3"},{"fix":"Upgrade to a actively maintained Prometheus client library and middleware (e.g., `prom-client` directly) to ensure ongoing security patches and compliance.","message":"Due to its abandonment, Menoetius will not receive security updates. Running it in production could expose your application to known or unknown vulnerabilities related to its dependencies or its own code.","severity":"breaking","affected_versions":">=0.0.3"}],"env_vars":null,"last_verified":"2026-04-23T00:00:00.000Z","next_check":"2026-07-22T00:00:00.000Z","problems":[{"fix":"Ensure `npm install menoetius` ran successfully and `const menoetius = require('menoetius');` is correctly placed. Given the package's age, consider if it's installed alongside incompatible Node.js or dependency versions.","cause":"The `menoetius` module was either not properly imported, or the package is corrupted/incomplete.","error":"TypeError: menoetius.instrument is not a function"},{"fix":"Run `npm install --save menoetius` to add the package to your project dependencies.","cause":"The `menoetius` package is not installed in your project's `node_modules` directory.","error":"Error: Cannot find module 'menoetius'"},{"fix":"While `request` is likely a transitive dependency, the ultimate fix for Menoetius's issues is to migrate to a modern, maintained Prometheus client solution.","cause":"Menoetius depends on the `request` package, which is now deprecated and might cause issues with newer Node.js versions or package managers.","error":"Error: The 'request' module is not found. Menoetius requires 'request' as a dependency."}],"ecosystem":"npm","meta_description":null,"install_score":null,"install_tag":null,"quickstart_score":null,"quickstart_tag":null}