Open-source alternatives to Json Server

Mock is a JavaScript API mocking tool and network request interceptor designed to decouple front-end development from back-end progress. It functions as an API simulation tool and mock data generator, allowing developers to build user interfaces and high-fidelity prototypes by mimicking the request and response cycle without a live server. The system provides a mechanism for intercepting outgoing HTTP calls and returning simulated data. It enables front-end prototyping by generating synthetic datasets to validate application behavior during automated testing cycles and development. Capabilit

CodeIgniter is a PHP web framework built on the Model-View-Controller pattern, designed for building full-stack web applications. It provides a lightweight toolkit with minimal configuration, organizing application logic into controllers, models, and views for clean separation of concerns. The framework includes a fluent query builder for constructing SQL statements programmatically, PSR-4 autoloading with namespace mapping, and a service-based dependency injection container for managing shared class instances. The framework distinguishes itself through its comprehensive set of built-in tools

Platform is a framework for building back-office applications and administrative dashboards using Laravel. It functions as a schema-driven UI framework and CRUD generator that automatically constructs database management interfaces, input forms, and validation rules from programmatic model definitions. The project distinguishes itself through a comprehensive backend UI kit that supports advanced data capture, including geographic coordinate mapping, tabular JSON data matrices, and marketing metadata tracking. It features a robust role-based access control system for managing resource visibili

Karate is an end-to-end testing framework and API test automation tool used to validate REST and SOAP APIs, drive browser interactions, and measure system performance. It functions as a unified solution for executing automated tests across both API backends and web frontends. The framework utilizes a custom domain specific language and Gherkin-style feature mapping to define requests and assertions. It includes an API mocking server to simulate backend responses, enabling development and integration testing without live dependencies. The tool covers a broad range of functional testing catego

JSONPlaceholder is a REST API mock server and JSON mocking service that provides a hosted frontend development sandbox. It functions as a fake backend that returns predefined JSON responses to simulate a REST API for development and testing. The service supports cross-origin resource sharing, allowing API integrations to be tested from different browser domains. It enables the simulation of CRUD operations and the retrieval of mock data without requiring a live database. The system maps URL patterns to a static JSON-based data store and handles requests statelessly. It includes capabilities

Apollo Client is a GraphQL client library and data fetching framework used to request data from a GraphQL server and synchronize that state within a frontend application. It functions as a remote state manager and a local state management tool, allowing developers to define client-side schemas and resolvers for data that does not reside on a remote server. The project features a normalized GraphQL cache that identifies objects by ID to ensure referential equality and consistent data updates across different queries. It also includes a GraphQL API mocking tool to simulate server responses and

This project is a PHP-based framework designed for the automated development of standardized web services. It functions as a backend toolkit that maps internal data models to REST and GraphQL endpoints, providing built-in support for resource management, data serialization, and hypermedia-aware API operations. The framework distinguishes itself through a metadata-driven architecture that uses class-level attributes to automatically derive API schemas, validation rules, and documentation. By analyzing these definitions at runtime, it generates machine-readable specifications and interactive in

Insomnia is a cross-platform API development environment that integrates a request debugger, schema design tools, a mocking server, and a test automation framework. It provides a unified workspace for sending requests and analyzing responses across REST, GraphQL, gRPC, and WebSocket protocols. The platform enables the design and preview of API specifications through a visual editor and allows for the simulation of backend behavior using mocking tools. It supports organizing and synchronizing API collections via local storage, cloud synchronization, or Git. The suite includes a command-line i

MSW is a JavaScript API mocking library and integration testing tool designed to intercept network requests at the network level. It allows for the definition of mock data and status codes using routing syntax to simulate server responses without requiring changes to the application source code. The project utilizes a service worker to proxy API calls in the browser, providing a mechanism for isolated frontend development and testing. It employs platform-specific network adapters to maintain a consistent mocking interface across both browser and Node.js environments. The library covers a ran

Prism is a set of tools for generating mock servers and validation proxies based on OpenAPI specifications or Postman collection files. It serves as an API contract testing tool to verify that API implementations adhere to formal contracts. The project provides an OpenAPI mock server that simulates API responses and a validation proxy that checks live HTTP traffic against an OpenAPI specification to identify implementation discrepancies. It also includes a mock server capable of mimicking API behavior based on exported Postman Collection files. The tool covers API behavior simulation and tra

Hyper is a low-level networking library designed for building high-performance HTTP clients and servers. It provides a foundational toolkit for creating network services that leverage asynchronous execution and memory-safe data handling, supporting both HTTP/1 and HTTP/2 protocols. The library distinguishes itself through a protocol-agnostic architecture that separates transport logic from HTTP semantics. It utilizes a service-trait abstraction to decouple network logic from the underlying transport, enabling developers to inject custom middleware for request interception and response transfo

This project is a comprehensive Python network request framework designed for both synchronous and asynchronous HTTP communication. It provides a high-performance client capable of executing non-blocking requests within event-driven applications, while also supporting standard blocking calls for simpler scripts. The library is built to operate natively across diverse asynchronous runtimes, automatically detecting and utilizing the underlying event loop for concurrency. What distinguishes this library is its modular architecture, which decouples request construction from network execution thro

This project is a comprehensive sample library and implementation guide for ASP.NET Core. It provides a collection of practical examples and projects that demonstrate how to build web applications, RESTful APIs, and high-performance services. The repository focuses on a variety of architectural patterns, including the development of Minimal APIs, contract-first gRPC services, and real-time communication using WebSockets and Server-Sent Events. It includes detailed implementations for user identity and security, such as token-based authentication and CSRF protection. The codebase covers a bro

This project serves as a comprehensive educational repository and technical reference collection, documenting a wide range of software engineering practices and modern development technologies. It provides a structured learning path for developers, curating tutorials and practical examples that cover the full lifecycle of application development, from initial project scaffolding to deployment and maintenance. The repository distinguishes itself by offering deep technical insights into complex architectural patterns, including actor-based concurrency models for managing parallel tasks and cont

Catch2 is a comprehensive framework for C++ software validation, providing an environment for unit testing, integration verification, and performance analysis. It enables developers to define and execute automated test suites and micro-benchmarks directly within their applications. The framework is distinguished by its header-only distribution, which allows for integration into existing build systems without requiring complex external dependencies. It utilizes a hierarchical section-based execution model that supports behavior-driven testing, allowing for shared setup and teardown logic acros

webpack-dev-server is a local web server designed to serve webpack bundles and trigger browser refreshes when source files change. It functions as a development environment that hosts bundled applications and provides a live reloading workflow. The project distinguishes itself by supporting hot module replacement to update modules in a running application without a full page reload. It also acts as an HTTP proxy to redirect network request paths to different backends and provides history API fallbacks specifically for hosting single-page applications. The server includes capabilities for mon

This project is a lightweight Node.js web server and command-line tool designed for hosting static assets and delivering local files over HTTP. It functions as a static site host that provides a minimal environment for serving HTML, CSS, and JavaScript files to web browsers. The server includes built-in support for TLS encryption to enable secure HTTPS access and allows for the configuration of cross-origin resource sharing headers. It also features basic authentication to restrict folder access via username and password verification. The system manages content delivery through browser cache

Payload is a headless content management system and application framework that uses a code-first approach to define data schemas and administrative interfaces. By utilizing a centralized, type-safe configuration object, it automatically generates database schemas, API endpoints, and a fully customizable admin panel. The system is built on a database-agnostic architecture, allowing it to interface with various storage engines while providing a unified, type-safe API for server-side operations, REST, and GraphQL. What distinguishes Payload is its deep extensibility and developer-centric design.

FastMCP is a Python framework designed for building servers that expose functions, resources, and prompts to AI models using the Model Context Protocol. It simplifies the development process by automatically deriving tool metadata, input schemas, and documentation directly from Python function signatures and type hints. The framework provides a unified container for managing these components, allowing developers to build modular applications that integrate seamlessly with AI assistants. The project distinguishes itself through its support for interactive, server-defined user interface compone

Moleculer is a Node.js microservices framework designed for building distributed systems. It functions as a distributed service broker, task orchestrator, and service mesh framework, enabling a decentralized architecture with built-in service discovery and load balancing. The project differentiates itself through a pluggable transport layer supporting protocols such as NATS, Redis, TCP, and Kafka, as well as a dedicated microservices API gateway that maps external HTTP and WebSocket requests to internal service actions. It includes built-in fault tolerance mechanisms, including circuit breake

Hono is a lightweight web framework built on Web Standard APIs that executes across JavaScript runtimes including Cloudflare Workers, Deno, Bun, and Node.js.

Quarkus is a Kubernetes-native Java framework designed for building high-performance, memory-efficient applications. It utilizes ahead-of-time native compilation to transform Java code into standalone, optimized binaries that eliminate the need for a virtual machine, enabling rapid startup and reduced memory consumption. By performing code augmentation during the build phase, it shifts heavy processing tasks away from runtime, ensuring that applications are optimized for cloud-native environments. The framework distinguishes itself through a unified approach to reactive and imperative program

Ant Design Pro is a comprehensive starter kit and administrative framework for building enterprise-level admin dashboards and professional user interfaces. It provides a structured project foundation and a set of React admin templates, including pre-defined layout blocks and routing configurations. The framework distinguishes itself by providing a built-in frontend mocking environment and mock-service middleware to simulate backend API responses during development. It also features integrated conversational AI components and assistant pages for embedding intelligent interactions directly into

This project is an API documentation management platform and mocking server. It provides a central system for organizing API specifications and managing metadata to maintain consistency across the development lifecycle. The toolset includes a mocking engine that generates simulated backend responses, allowing frontend development to proceed without a live backend service. It also functions as a static documentation generator that converts dynamic API specifications into offline files for distribution and archival. The platform is delivered as a containerized toolset, packaging the server and

Pinot is a distributed, columnar analytical database designed for high-concurrency, low-latency query processing. It functions as a real-time OLAP datastore, enabling interactive, user-facing analytics by ingesting and querying massive datasets from both streaming and batch sources. The system architecture relies on a centralized controller for cluster coordination and a distributed segment-based storage model to ensure horizontal scalability. The platform distinguishes itself through a hybrid ingestion pipeline that unifies real-time event streams and historical batch data into a single quer

This project is a database abstraction layer for Laravel that implements the repository pattern to decouple business logic from Eloquent database queries. It provides a standardized interface for data retrieval, pagination, and filtering. The system includes a query criteria mechanism for applying reusable search conditions based on request parameters and a caching wrapper that automatically clears stored results during record creation, updates, or deletions. It also features a presentation layer to transform raw database model attributes into formatted output for user interfaces. Additional

This project is a multi-protocol API simulation and mocking system designed to replace external dependencies during development and testing. It provides an API mocking server, a network traffic proxy, and specialized simulators for language model services and identity providers. The system distinguishes itself through deep AI simulation capabilities, including the emulation of language model providers and Model Context Protocol servers using JSON-RPC 2.0. It supports multi-turn conversational logic, state tracking for AI chat APIs, and the visualization of agent execution through call graphs