TypeScript icon, indicating that this package has built-in type declarations

3.0.14 • Public • Published

impress logo ci Status snyk npm downloads/month npm downloads license

Enterprise application server for Node.js: secure, lightweight, interactive, and scalable.


First Node.js server scaled with multithreading and extra thin workload isolation. Optimized for high-intensive data exchange, rapid development, and clean architecture. Provides everything you need out of the box for reliable and efficient backend, network communication with web and mobile clients, protocol-agnostic API, run-time type validation, real-time and in-memory data processing, and reliable stateful services.

Weak sides: not a good choice for content publishing including blogs and online stores, server-side rendering, serving static content and stateless services.

Strong sides: security and architecture for enterprise-level applications, long-lived connections over websocket to minimize overhead for cryptographic handshake, no third-party dependencies.

Quick start

API endpoint example: application/api/example.1/citiesByCountry.js

async ({ countryId }) => {
  const fields = ['cityId', 'name'];
  const where = { countryId };
  const data = await'City', fields, where);
  return { result: 'success', data };

You can call it from client-side:

const res = await metacom.api.example.citiesByCountry({ countryId: 3 });

Metarhia and impress application server way

  • Applied code needs to be simple and secure, so we use sandboxing with v8 isolated contexts, worker threads and javascript closures;
  • Domain code should be separated from system code; so we use DDD, layered (onion) architecture, DI, SOLID and GRASP principles, contract-based approach;
  • Impress supports stateful applications with RPC and client-session sticky to servers; microservices, centralized or distributed architecture;
  • No I/O is faster even than async I/O, so we hold state in memory, share it among multiple threads and use lazy I/O for persistent storage;
  • We use just internal trusted dependencies, no third-party npm packages; total Metarhia technology stack size is less than 2mb.


  • API auto-routing calls to endpoint for rapid API development (no need to add routes manually)
  • API concurrency: request execution timeout and execution queue with both timeout and size limitations
  • Schemas for API contract, data structures validation, and domain models
  • Application server supports different API styles: RPC over AJAX and over Websocket, REST, and web hooks
  • Multiple protocols support: HTTP, HTTPS, WS, WSS
  • Auto loader with start hooks, namespace generation for code and dependencies
  • Live reload of code through filesystem watch
  • Graceful shutdown with stop hooks
  • Minimal dependencies and reduced code size
  • Layered architecture: api, domain logic, data access layer, and system code layer (hidden)
  • Code sandboxing for enhanced security and execution context isolation
  • Code protection: reference pollution prevention, prototype pollution prevention
  • Multi-threading for CPU utilization and execution isolation
  • Load balancing for simple scaling with redirection to multiple ports
  • Caching: in-memory caching for APIs and static files
  • Configuration: environment-specific application settings
  • Database access layer compatible with PostgreSQL with SQL-injection protection
  • Persistent sessions with authentication, groups, and anonymous sessions
  • Buffered logging (lazy write) with log rotation (keep logs N days) and console interface
  • Testing: integrated node.js native test runner and table-test support
  • Inter-process communication and shared memory used for state management
  • File utilities: upload, download, support for partial content and streaming
  • Task Management: scheduled task execution at specific intervals or certain times

TODO list

Those features will be implemented in nearest future (3-6 months):

  • Server health monitoring
  • Database migrations
  • State synchronization mechanism with transactions and subscription
  • Multi-tenancy support


  • Node.js v18.x or v20.x
  • Linux (tested on Fedora v36-38, Ubuntu v18-23, CentOS v7-9)
  • Postgresql v11-16
  • OpenSSL v3 or later (optional, for https & wss)
  • certbot (recommended but optional)

License & Contributors

Copyright (c) 2012-2024 Metarhia contributors. See github for full contributors list. Impress Application Server is MIT licensed. Project coordinator: <>

Package Sidebar


npm i impress


Weekly Downloads






Unpacked Size

70.1 kB

Total Files


Last publish


  • timur.shemsedinov
  • aqrln
  • belochub
  • nechaido