Open-source alternatives to Oapi Codegen

NSwag is a toolchain for the .NET ecosystem designed to automate the generation of API documentation, server controllers, and typed client proxies from OpenAPI contracts. It functions as a contract-first API tool that enables the creation of server-side boilerplate and client libraries based on predefined specifications. The suite distinguishes itself through its ability to extract OpenAPI specifications from existing ASP.NET Core code via reflection and its capacity to generate type-safe TypeScript client proxies. It also provides an interactive documentation server that hosts and renders th

go-swagger is a toolkit for working with Swagger/OpenAPI 2.0 specifications in Go. It generates server, client, and CLI code from a specification document, and can also produce a specification by scanning annotated Go source code. The project includes a static validation engine that checks documents against the schema and project-specific rules, and a specification transformation pipeline that resolves, flattens, and merges documents. The toolkit generates both client and server code from the same specification, ensuring consistency in request and response handling. It also produces a command

OpenAPI Generator CLI is a command-line utility designed to automate the creation of API artifacts from specification files. It functions as a tool for generating client libraries, server stubs, and documentation, enabling developers to produce consistent boilerplate code and reference materials across various programming languages. The project provides a wrapper that manages the lifecycle of a Java-based execution engine, which performs the actual code synthesis using logic-less templates. To ensure reproducible results and avoid dependency conflicts on the host system, the tool supports ver

Kratos is a toolkit for building cloud-native microservices in Go. It provides a comprehensive suite of framework primitives, including a dedicated toolset for API-first development using Protobuf to generate server and client code for gRPC and HTTP. The project is distinguished by its pluggable service infrastructure, which allows for the swapping of configuration stores, service registries, and data encoding formats. It utilizes a composable middleware pipeline to inject cross-cutting concerns such as authentication, request validation, and circuit breaking into the service flow. The frame

Wasp is a declarative full-stack web framework that enables developers to build and deploy applications by defining their architecture in a centralized configuration. By using a high-level specification, the framework automates the orchestration of frontend, backend, and database components, ensuring that infrastructure concerns like routing, authentication, and data modeling are handled consistently across the entire stack. The framework distinguishes itself through its compiler-driven approach, which translates declarative configurations into cohesive, production-ready codebases. It provide

SwiftGen is a tool that creates strongly typed Swift references for assets, strings, and storyboards to eliminate manual string-based APIs. It functions as a code generator that maps localization keys, static assets, and data models into typed source code using a template-based engine. The project uses custom templates to define the exact structure and syntax of the generated code. This allows the generated output to match specific project conventions while providing a flexible system for mapping translation keys and converting local files, colors, and fonts into typed constants. The tool co

dbtpl is a database model generator and schema introspector that produces type-safe source code and data models from SQL database schemas. It functions as a command line tool that maps SQL types to Go structs and execution functions, while providing a template-based system for creating custom source code and schema definitions. The tool supports multiple database engines, including PostgreSQL, MySQL, SQLite, Oracle, and SQL Server. It distinguishes itself by allowing users to define custom output formats through text templates and the ability to generate compatible model definitions for the D

Elysia is a high-performance TypeScript web framework designed for building type-safe backend services. It provides a modular, plugin-based architecture that allows developers to compose server logic, middleware, and validation schemas into scalable application instances. By leveraging native web standards, the framework ensures portability across diverse JavaScript runtimes, including Node.js, Deno, and various edge computing environments. The framework distinguishes itself through its focus on end-to-end type safety, automatically synchronizing request and response definitions between the s

create-t3-app is a full stack web framework initializer and project scaffolder. It functions as a command line tool for initializing Next.js applications, acting as a TypeScript full stack starter that generates a predefined folder structure and configuration files. The tool focuses on establishing a typesafe full stack architecture. It enforces end-to-end type safety between the client and server, ensuring that data types remain synchronized across the entire application stack to prevent runtime errors. The initializer automates the setup of a full stack development environment by bootstrap

Encore is a distributed systems framework designed to unify backend development, infrastructure provisioning, and observability. It functions as an infrastructure-as-code platform that allows developers to define cloud resources, databases, and messaging topics directly within their application code. By analyzing these declarations at compile-time, the system automatically manages the deployment of cloud resources and security policies, ensuring parity between local development and production environments. The platform distinguishes itself through its integrated development experience, which

ihp is a type-safe web framework and full-stack application orchestrator designed for PostgreSQL. It functions as a server-side rendering framework and a type-safe ORM that automatically generates record types from SQL schemas to ensure compile-time query validation. The platform distinguishes itself by verifying routing, database queries, and templates at compile time to prevent runtime crashes. It implements real-time web interfaces using WebSockets for instant data synchronization and employs server-driven hypermedia for partial DOM patching. The framework covers a broad range of integrat

This project is a PHP clean code guide and software architecture reference. It provides a set of standards, naming conventions, and design patterns intended to improve the long-term maintainability and readability of PHP codebases. The guide emphasizes a structured approach to refactoring and system design, focusing on the application of SOLID principles to reduce coupling and increase extensibility. It advocates for object-oriented design through the use of composition over inheritance, the use of final classes to prevent unexpected overrides, and the implementation of strict type declaratio

Redoc is an API documentation generator that transforms standard API specification files into interactive, responsive, and highly customizable web-based documentation interfaces. It provides a three-panel layout that includes synchronized navigation, code samples, and search functionality, allowing developers to explore endpoints and schemas directly within a browser-based environment. Beyond rendering, the project functions as an API governance toolkit that enforces structural standards and quality rules across API definitions. It includes a suite of processing utilities for bundling, splitt

This project is a set of software engineering standards and architectural patterns for writing maintainable and refactorable TypeScript code. It provides a comprehensive guide for implementing clean code principles, focusing on the application of SOLID design and structural patterns to build decoupled systems. The framework prioritizes composition over inheritance and utilizes dependency inversion to reduce system coupling. It establishes standards for strict static typing and the use of read-only modifiers to ensure type safety and eliminate runtime errors. The guidance covers a broad range

This project provides a TypeScript software development kit for the Model Context Protocol, a standard designed to facilitate bidirectional communication between AI applications and external data sources or tools. It serves as a foundational framework for building both clients and servers, enabling language models to interact with external systems through a unified, decoupled interface. The SDK distinguishes itself by implementing a transport-agnostic connection layer that supports both local standard input-output streams and remote HTTP endpoints. It utilizes a JSON-RPC message bus to manage

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

Sanic is an asynchronous Python web framework designed for building high-performance APIs and services. It operates as a production-ready ASGI web server, utilizing a non-blocking event loop to handle concurrent requests and maximize throughput. The framework is built to support scalable architectures, offering built-in worker process management to distribute traffic across available CPU cores. What distinguishes Sanic is its focus on modularity and developer-centric tooling. It features a blueprint-based system for organizing complex applications into pluggable components, alongside a robust

This project is a static analysis tool and linter for Ruby on Rails designed to identify architectural smells and violations of best practices. It serves as a code quality linter, architectural auditor, security scanner, and performance analyzer for Rails applications. The tool evaluates the separation of concerns between controllers, models, and view templates to reduce technical debt. It identifies suboptimal coding patterns and enforces stylistic consistency, while specifically scanning for security vulnerabilities such as unprotected mass assignment in models. The analysis surface covers

BAML is a prompt engineering framework and LLM client generator that defines AI prompts as type-safe functions. It serves as a structured data extraction tool and workflow orchestrator, transforming unstructured model responses into strongly typed objects using a custom schema language and alignment algorithms. The project distinguishes itself by using a compiler to generate language-specific boilerplate code for API communication and output parsing. It features a dedicated environment for designing complex prompt templates with conditional logic and reusable snippets, and employs genetic alg

This project is a discovery-based API client and a Python library for interacting with Google services. It enables Python applications to make authenticated requests to Google Cloud and Workspace APIs. The library functions by consuming machine-readable metadata descriptions of remote web services to build functional client interfaces at runtime. This allows for dynamic API consumption by generating interfaces from metadata rather than using manual endpoint mapping. The project covers a range of integration capabilities, including cloud service automation and development for Google Workspace

ServiceStack is a high-performance .NET web framework designed for building type-safe APIs using strongly-typed request and response objects. It functions as a message-based API engine that decouples business logic from the transport layer, allowing services to be exposed via multiple protocols including HTTP, gRPC, and various message queue providers. The framework is distinguished by its type-safe API generator, which produces native client SDKs and data transfer objects from service metadata across multiple languages. It also includes a distributed service gateway for microservices orchest

openapi-ts is a tool and orchestrator used to convert OpenAPI specifications into type-safe TypeScript SDKs and HTTP client implementations. It automatically generates typed interfaces and request functions from API definitions to ensure consistency between the server and the client. The project employs a transport-agnostic client interface, decoupling high-level API calls from the underlying network library. It uses a plugin-based generation pipeline and a custom plugin architecture to allow for the customization of output types and validation schemas. The system provides capabilities for n

Vue-typescript-admin-template is a TypeScript-based admin panel starter built with Vue CLI 3, providing a complete foundation for building enterprise back-office interfaces. It enforces type safety across Vue components using TypeScript, reducing runtime errors and improving code maintainability, while offering a dynamic route permission system that controls sidebar navigation and page access by mapping user roles to route permissions at runtime. The template includes a mock API service layer that simulates backend responses for frontend development without a live server, along with internati

Phan is a static analyzer and type checker for PHP that identifies bugs and type incompatibilities without executing the code. It serves as a quality gate for continuous integration pipelines and a tool for verifying type safety, specifically checking union types, generics, and array shapes. The project is distinguished by its use of a background daemon and Language Server Protocol implementation, which provide real-time diagnostics and navigation within editors. It also features a baseline-based suppression system that allows developers to record existing errors in a snapshot file to focus e

This project is a collection of Go packages and a programmatic interface for interacting with Google services and Google Cloud resources via REST APIs. It functions as a client library and SDK that transforms raw HTTP requests into structured Go function calls. The library utilizes discovery-based client generation to create type-safe clients from API discovery documents. It separates the acquisition of authorization tokens from the request logic through a token-source based authentication model. The project covers identity management and authentication via OAuth 2.0, service accounts, and A

Orval is an OpenAPI-to-TypeScript code generator that produces fully typed API clients, data-fetching hooks, mock data, validation schemas, and server handlers from OpenAPI or Swagger specifications. It reads any YAML or JSON API specification and generates TypeScript interfaces, HTTP request functions, and framework-specific integration code that ensures compile-time correctness for all API calls. The project distinguishes itself by generating production-ready data-fetching hooks for React Query, Vue Query, Svelte Query, Solid Query, Angular, and SWR, complete with automatic cache invalidati

Ajv is a high-performance data validation framework that compiles JSON schemas into optimized, standalone JavaScript functions. By transforming declarative schema definitions into executable code, it eliminates runtime interpretation overhead and provides a secure, efficient way to enforce data integrity across both browser and server environments. The library distinguishes itself through its focus on performance and type safety. It employs advanced compilation techniques, including abstract syntax tree optimization and function caching, to ensure rapid validation. Beyond standard checks, it