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    Impressive totalitarian style Multipurpose Application Server for node.js. All decisions are made. Solutions are scaled. Tools are provided and optimized for high load. Ready for applied development and production.
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    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: <>

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