Open-source alternatives to Crystal

PostgREST is a standalone web server that automatically transforms a PostgreSQL database into a RESTful API. It serves as an API gateway that translates HTTP requests into SQL queries, mapping the database schema directly to endpoints without the need for manual route definitions. The system utilizes a JWT authentication layer to validate user identities and map incoming web requests to specific database roles. This allows the server to delegate authorization and permission enforcement to the internal PostgreSQL role system. It includes a generator for OpenAPI specifications to provide stand

WPGraphQL is a GraphQL interface for WordPress that transforms a WordPress installation into a headless content source. It functions as a GraphQL schema provider that maps database structures and relational data into a standardized schema, exposing posts, pages, and custom data types through a single flexible endpoint. The project includes an integrated API query builder and schema explorer, allowing for the visual composition of queries and real-time validation of responses. It provides a system for extending the schema with custom fields and relationships to expose specific business data.

Vendure is a Node.js e-commerce engine and headless commerce framework built with NestJS and TypeScript. It serves as a multi-channel commerce platform that manages product catalogs, orders, and customers via a strongly typed GraphQL API. The platform is distinguished by its highly extensible architecture, featuring a customizable administrative dashboard where developers can inject custom React components and entity views. It supports multi-channel commerce, allowing the isolation of products, currencies, and regional catalogs from a single unified backend. The engine covers a broad range o

This project is an interactive educational platform and comprehensive curriculum designed to teach developers how to build, query, and integrate GraphQL APIs into full-stack applications. It provides a structured learning environment for mastering core concepts such as schema design, query execution, and the implementation of data-driven interfaces. The platform distinguishes itself by focusing on the practical application of real-time data synchronization and backend architecture. It guides users through the process of connecting frontend frameworks to relational databases, implementing role

Strawberry is a type-safe GraphQL library for Python that enables the design of schemas using Python type annotations and dataclasses. It functions as an asynchronous GraphQL server and execution engine, providing a bridge to expose schemas across ASGI-compliant web frameworks such as FastAPI, Django, Flask, and Litestar. The project implements GraphQL Federation, allowing for the creation of distributed schemas and entities that merge into a unified supergraph across multiple services. It also includes a dedicated toolkit for the Relay specification, supporting global object identification a

Cube is a semantic data layer that provides a unified framework for defining business metrics, dimensions, and relationships across diverse data sources. By acting as a headless business intelligence engine, it transforms raw data into a governed model that can be queried via SQL, REST, and GraphQL interfaces. This architecture ensures consistent data definitions and logic across all downstream analytical applications and reporting tools. The platform distinguishes itself through its integrated conversational AI capabilities, which allow users to explore data using natural language. It orches

GraphQL-Ruby is a Ruby library for building GraphQL APIs with a strongly typed schema and a dedicated query execution engine. It provides a comprehensive framework for mapping application objects to a formal type system, enabling structured data fetching through defined resolvers. The project distinguishes itself with advanced performance and delivery mechanisms, including a data loader for batching and caching to prevent N+1 query patterns. It supports high-performance data delivery through incremental response streaming, deferred query responses, and parallel data fetching using fibers. Add

Higress is an AI API gateway and cloud-native traffic manager that functions as a Kubernetes ingress controller. It provides a centralized system for routing, securing, and optimizing traffic directed toward large language models, AI agents, and microservice architectures. The project distinguishes itself through deep AI orchestration, including the ability to host and manage Model Context Protocol servers that transform REST APIs into tools for AI agents. It features specialized AI infrastructure for model request proxying, protocol translation across multiple providers, and semantic-based c

PostGraphile is an automated tool that converts a PostgreSQL database schema into a fully functional GraphQL API. It serves as a GraphQL execution engine and schema orchestrator, utilizing database schema introspection to retrieve strongly typed metadata directly from PostgreSQL. The project features a modular system for composing and standardizing GraphQL schemas through plugins, which manage naming conventions and connections. It includes a PostgreSQL query builder that constructs dynamic, SQL-injection-proof queries using tagged template literals. The system employs a declarative query pl

Yoga is a GraphQL server framework and runtime-agnostic HTTP handler used to build and deploy GraphQL APIs. It functions as a toolkit for managing schemas and resolvers, providing a spec-compliant environment for hosting APIs across diverse JavaScript runtimes, including Node.js, Deno, Bun, and serverless cloud environments. The project distinguishes itself through its ability to act as an Apollo Federation gateway, composing multiple subgraphs into a single unified supergraph. It also serves as a dedicated subscription server, delivering real-time data streaming via both WebSockets and Serve

Ever Gauzy is an integrated business management suite providing an ERP and CRM framework for professional services automation. It functions as a multi-tenant SaaS platform that combines time tracking, billing, and human resource management into a unified system. The project is distinguished by its headless architecture, utilizing a REST and GraphQL API gateway to expose business operations. It features a Model Context Protocol server that allows AI assistants to interact with system data and execute functional tools for automated business workflows. The platform covers a broad operational su

Gauzy is an open business management platform and multi-tenant enterprise resource planning system. It provides a modular business framework designed to manage core organizational operations through a unified web interface or as a headless business API. The platform is distinguished by its integration with the Model Context Protocol, allowing it to act as a server that exposes business data and system functions as tools for AI assistants. It utilizes a dynamic plugin architecture and a dedicated marketplace to extend core business entities and services. The system covers a broad range of ope

jwt-auth is a PHP package providing JSON Web Token authentication for Laravel and Lumen applications. It serves as a token provider and stateless session manager, allowing applications to issue and validate signed tokens to manage user identity across network requests. The library implements stateless API security by verifying identity tokens sent in request headers, removing the requirement to store session data on the server. It uses signed tokens to verify user credentials and restrict access to protected resources. The project provides capabilities for user access control, authentication

DataEase is an open-source, self-hosted business intelligence platform designed for building interactive data visualizations and managing analytical reporting. It provides a centralized environment where users can construct dashboards through a drag-and-drop interface, connecting to diverse data sources including relational databases, data warehouses, and external APIs. The platform distinguishes itself through its focus on embedded analytics and enterprise-grade governance. It allows for the seamless integration of charts, dashboards, and management modules into third-party web applications

This project is a production-ready template for building RESTful APIs using Node.js and the Express web framework. It provides a pre-configured structure for backend services, integrating a MongoDB Mongoose ODM framework for data modeling and a token-based security system for managing user identity. The boilerplate distinguishes itself through automated API documentation generated via Swagger by parsing code comments. It implements a layered controller architecture and a middleware-based request pipeline to separate routing logic from business logic and security processing. The system covers

Apollo Server is a spec-compliant JavaScript implementation for building GraphQL APIs that resolve queries and mutations based on a defined schema. It functions as a Node.js framework that integrates GraphQL functionality into various web frameworks and serverless environments through middleware. The project provides a federated GraphQL gateway that aggregates multiple distributed subgraphs into a single unified entry point. It includes a built-in interactive API sandbox for testing operations at the server endpoint and a schema registry client to automate the synchronization of API definitio

Davinci is a business intelligence and data visualization platform used for building interactive dashboards and reports. It functions as a SQL-based dashboard builder and multi-tenant analytics service that connects to databases via JDBC and CSV files to transform raw data into visual components. The platform is distinguished by its granular security model, which includes row-level and column-level permissions integrated with LDAP and OAuth2 authentication. It also provides an embedded visualization tool that allows secure, parameterized charts and dashboards to be inserted into external appl

django-extensions is a specialized toolset for the Django framework providing utilities for database visualization, application debugging, development environment management, and custom management command execution. It functions as a collection of tools designed to automate development tasks and inspect the internal state of an application. The project provides a database visualization tool for generating diagrams of data models and comparing schemas to map complex relationships. It also includes a debugging utility to intercept email traffic and audit user permissions to troubleshoot applica

Mercure is an HTTP-based message broker and real-time pub/sub server that routes asynchronous data updates to authorized subscribers. It functions as a centralized hub that receives data via standard HTTP requests and broadcasts it to web clients using the Server-Sent Events protocol. The project distinguishes itself by replacing WebSockets with a unidirectional HTTP connection, leveraging HTTP/2 and HTTP/3 for multiplexed, low-latency delivery. It implements a secure access control layer using JSON Web Tokens and JSON Web Signatures to validate the identity of publishers and subscribers, and

FileBrowser is an open-source, self-hosted file management interface that runs as a single binary with no external dependencies. It provides a web-based interface for browsing, uploading, editing, and sharing files on a remote server, with a core architecture built on JWT-based stateless authentication and a rule-based path permission engine that controls access at the directory level. The project distinguishes itself through a comprehensive access control system that supports multi-provider authentication including OIDC, LDAP, external JWT, and two-factor authentication, alongside granular p

Practicalnode is a comprehensive educational resource and backend development framework for mastering server-side programming with Node.js. It provides a structured approach to building scalable network services, REST APIs, and real-time applications using asynchronous JavaScript. The project serves as a detailed implementation guide for several core backend patterns, including MongoDB data modeling and the construction of REST API development kits. It emphasizes a specific workflow for Docker containerization and offers a variety of strategies for managing user identity through stateless tok

express-graphql is a GraphQL API server implementation and HTTP middleware that connects a GraphQL schema to an HTTP server. It provides a request parser to extract queries and variables from various content types and a context provider to inject HTTP request data and session state into resolver functions. The library includes a browser-based interactive IDE that detects GET requests to serve an HTML interface for testing queries and inspecting responses. It also supports a custom execution pipeline, allowing for the override of default parsing, validation, execution, and error formatting fun

This project is a reference implementation and boilerplate for building RESTful services using the Gin web framework in Go. It provides a structured backend architecture featuring modular routing and middleware to serve as a template for Go web applications. The project distinguishes itself through a comprehensive set of integrated systems, including a security layer for user authentication and private endpoint protection using JSON Web Tokens. It also implements a high-speed memory storage layer via Redis to cache frequent database queries and a containerized runtime environment for consiste

This project is a Node.js and Express backend application that provides a RESTful API for managing video content, channel subscriptions, and community engagements. It utilizes a MongoDB NoSQL database for document management and leverages a middleware-based request pipeline to handle business logic and network requests. The system implements a secure user authentication framework using password hashing and JSON Web Tokens to manage sessions and protect private API routes. It also integrates cloud-based blob storage to handle the uploading and distribution of images, documents, and video files

InsForge is a backend-as-a-service platform that provides an integrated suite of tools for managing relational databases, identity provision, object storage, and serverless compute. It functions as an open-source identity provider and a PostgreSQL database manager featuring integrated vector storage and row-level security. The platform serves as an LLM orchestration gateway, offering a unified endpoint to route requests across various AI providers through an OpenAI-compatible interface. It enables AI-driven application generation and connects AI agents to backend resources using a standardize

Jazz is a local-first relational database and synchronization framework designed for offline-capable applications. It functions as a reactive state management system that treats database records as the primary source of truth, automatically updating user interfaces in real time as underlying data changes. The project distinguishes itself through a collaborative data synchronization model that utilizes row-level versioning to track branching edit histories. It implements a security engine based on identity-claim row security, which enforces granular permissions on individual records, and suppo

This project is a Node.js library for implementing and managing JSON Web Tokens. It functions as a cryptographic token manager and authentication tool used to sign, verify, and decode tokens to securely transmit claims between parties. The library supports both symmetric and asymmetric signing algorithms, including HMAC and RSA. It enables the creation of digitally signed tokens using secrets or private keys, and provides mechanisms to validate token signatures and verify embedded claims such as expiration and issuer. The tool covers a range of identity and access capabilities, including sta