Open-source alternatives to Springfox

swagger-core is a set of libraries for parsing, generating, and serializing OpenAPI specifications to automate REST API documentation. It provides tools to read, validate, and transform JSON or YAML specifications into programmable objects, as well as a generator that scans source code and annotations to create formal technical descriptions of an API. The project enables bi-directional specification serialization, allowing in-memory API definitions to be converted between native language objects and structured files. It uses a plugin-based scanning mechanism and annotation-driven generation t

utoipa is a Rust API documentation tool used to generate machine-readable OpenAPI specifications. It functions as a specification generator and schema mapper that converts Rust structs and enums into compliant OpenAPI schemas. The project distinguishes itself by using procedural macros and traits to automate metadata extraction from code. It supports complex data modeling, including generics, polymorphism, and recursive type resolution, while synchronizing field renaming and tagging from serialization attributes. It also enables the composition of modular specifications, allowing multiple sma

Hug is a type-driven Python web framework designed for building APIs. It uses Python type annotations to automatically validate and convert incoming request data and to format outgoing responses. The framework functions as an automated documentation tool by extracting function signatures and markers from source code to generate accessible API specifications. It also supports non-blocking coroutines for asynchronous API processing to handle background tasks without interrupting the main request cycle. The project provides capabilities for REST API development, including route mapping, endpoin

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

Connexion is a spec-first Python web framework designed to derive server behavior and validation logic directly from a predefined API contract. It enables the development of web services by using an OpenAPI specification to automatically handle routing, request validation, and response serialization. The framework distinguishes itself by acting as an OpenAPI request validator and mock server. It can simulate API behavior by serving example responses based on specification schemas, allowing for frontend development and prototyping before a backend implementation is completed. Additionally, it

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

Eve is a REST API framework that maps database collections to web resources through declarative configuration files. It functions as a database-to-API mapper, automatically exposing data as RESTful endpoints with built-in support for CRUD operations and schema-based request validation. The project distinguishes itself through a HATEOAS API engine that generates hypermedia links and resource schemas for dynamic client discovery. It also includes an automated Swagger documentation generator that produces interactive specifications for client SDK generation and testing. The framework provides a

openapi-devtools is a browser extension and OpenAPI specification generator that captures network traffic to automatically document the API structures of websites and applications. It functions as an HTTP traffic capturer and browser-based documentation tool, mapping real-time network requests into standardized API specifications. The tool enables API reverse engineering by intercepting outbound HTTP traffic and using heuristic-based merging to combine headers, bodies, and parameters from multiple requests into unified endpoint definitions. These captured definitions can be visualized as huma

Swag is a documentation tool for Go that generates standardized API specification files by parsing declarative annotations within source code. It functions by analyzing source files to extract metadata from comments and function signatures, transforming them into machine-readable formats such as JSON or YAML. This process ensures that technical documentation remains synchronized with the underlying code structure throughout the development lifecycle. The tool distinguishes itself through its ability to perform static source code parsing and type-system reflection, which allows it to map compl

Showdoc is a technical documentation platform and knowledge management system designed to centralize project specifications, internal manuals, and technical guides. Built as a PHP web application, it provides a collaborative environment for teams to organize and share information across software development organizations. The platform distinguishes itself through its ability to automate documentation workflows by parsing source code comments and synchronizing technical records with the current state of a codebase. It also features specialized tools for managing RESTful API documentation and g

Django Ninja is a high-performance framework for building type-safe REST APIs using Django. It functions as an OpenAPI API framework and a type-safe wrapper that utilizes Python type hints to handle request validation and response serialization. The project distinguishes itself by integrating Pydantic-based data modeling to convert JSON inputs into strongly typed Python objects. It automatically generates OpenAPI schemas and interactive documentation pages directly from defined endpoint signatures. The framework supports asynchronous request processing to handle concurrent tasks. It employs

This project is a centralized API specification registry and governance framework. It serves as a source of truth for structured API schemas, gRPC definitions, and data models used to maintain consistency across a large ecosystem of services. The system functions as a multi-language client generator, transforming standardized interface definitions into executable source code and language-specific libraries. This process ensures that client libraries and technical documentation remain synchronized by deriving them directly from the original interface definitions. The project also covers the m

mitmproxy2swagger is a tool that transforms captured mitmproxy network traffic into structured OpenAPI schemas for reverse-engineering REST APIs. It functions as an OpenAPI schema converter and network traffic documentation utility, extracting API endpoints and data structures from captured network packets to create formal technical references. The tool enables the reconstruction of undocumented APIs by converting intercepted HTTP request and response patterns into specifications. It supports merging multiple traffic capture files into a single schema to incrementally expand an API map and ut

Goa is a design-first Go framework that generates server and client code, documentation, and request validation from a single declarative domain-specific language (DSL). At its core, it provides a Go DSL for defining API endpoints, data types, and error models, which compiles into fully functional HTTP and gRPC server stubs, client packages, and OpenAPI specifications. The framework distinguishes itself through its plugin-extensible code generation pipeline, allowing custom code generation steps, middleware, or transport layers to be added via plugins. It supports multiple transport protocols

Swagger Codegen is a template-driven engine and multi-language toolkit used to generate API client SDKs, server stubs, and human-readable documentation from OpenAPI specifications. It translates these specifications into functional libraries and boilerplate routing code across various target programming languages. The tool utilizes a pluggable generator module system and an integrated template engine, allowing for the customization of generated source code and the creation of new language-specific generators. It supports flexible specification sourcing via local files, remote HTTP endpoints,

TypeSpec is a language for defining cloud API shapes and generating OpenAPI, JSON Schema, and client/server code from a single source of truth. It functions as a protocol-agnostic API designer that models REST, gRPC, and other API protocols using a unified, extensible syntax, with a decorator-based metadata system for attaching metadata, validation rules, and lifecycle visibility to API models and operations. The compiler produces OpenAPI 3.0 specifications and other artifacts, and the tool supports declaring API versions and tracking changes to models, properties, and operations across releas

orpc is a contract-first API development framework for TypeScript that starts with a shared contract definition and generates type-safe clients and servers from that single source of truth. It guarantees end-to-end type safety, meaning inputs, outputs, errors, and streaming data are all checked at compile time across the client–server boundary. What distinguishes orpc from typical RPC frameworks is its ability to export contracts as OpenAPI specifications, to optimize server-side rendering by calling API handlers directly inside the server process, and to support real‑time bidirectional commu

apidoc is a source-code API documentation generator that parses specialized annotations within comments to automatically create a searchable API documentation website. It functions as an annotation-based API parser and a static documentation site generator, extracting definitions directly from the codebase to maintain a synchronized reference. The tool is designed as a multi-language parser, using configurable regular expressions to extract metadata from various programming languages. It can also serve as a JSON API definition exporter, converting source-code comments into raw JSON files for

NSwag is an OpenAPI toolchain for .NET that provides a suite of generators for converting OpenAPI specifications and JSON schemas into clients, server stubs, and structured documentation. It enables the creation of type-safe client libraries and data transfer objects, as well as the generation of OpenAPI specifications by analyzing .NET controllers. The project supports contract-first API development by generating server controller stubs from specifications and offers dedicated TypeScript API integration to ensure type safety in frontend applications. It also provides tools for hosting intera

APIStar is an OpenAPI framework providing a toolkit for building and verifying web APIs. It functions as an API schema validator, a traffic auditor, and a documentation generator to ensure compliance with API specifications and data types. The project converts OpenAPI and Swagger schemas into visual developer guides using customizable themes. It also implements a dynamic API client that adapts to defined schemas to send requests to remote servers. The framework includes capabilities for validating API schemas to identify structural mistakes and auditing incoming and outgoing web traffic agai

API Platform is a headless content management system engine and framework used to build REST and GraphQL APIs. It utilizes schema-driven generation to automatically produce web endpoints based on predefined data model definitions. The platform focuses on semantic data modeling, using structured classes and ontologies to ensure information is organized for search engines and semantic web tools. It provides an automated OpenAPI specification generator and a declarative system for creating administration dashboards to manage data records without custom frontend code. The system includes capabil

Postcat is an integrated platform for API design and documentation, serving as a REST API client and a mock server. It provides a workspace to define technical requirements and data schemas, allowing development teams to align on interface behavior. The platform features a plugin architecture that enables the integration of third-party tools and custom capabilities. It decouples frontend and backend development cycles by generating simulated server responses based on predefined data structures. The toolset includes an environment management system for switching between development, staging,

This project is a REST-to-gRPC API gateway and JSON reverse proxy that translates RESTful HTTP requests into gRPC service calls. It functions as a protocol buffer proxy generator, providing the tools necessary to bridge JSON-based HTTP traffic with backend gRPC servers. The system distinguishes itself by automating the creation of reverse-proxy servers and stubs through protobuf-driven code generation. It also includes a dedicated OpenAPI specification generator that produces OpenAPI v2 and v3 documents from gRPC service definitions and annotations. The project covers a broad range of integr

Sphinx is an extensible documentation framework and multi-format document publisher. It serves as a technical content organizer that converts reStructuredText markup and Python source code comments into structured documentation for technical projects. The system transforms a single set of markup files into multiple output formats, including HTML, LaTeX, EPUB, and Texinfo. It functions as a Python API documentation tool, extracting documentation directly from source code to maintain synchronized technical reference manuals. The framework organizes complex information into hierarchies with aut

This framework serves as a bridge between backend services and AI agents by implementing the Model Context Protocol. It enables developers to expose existing application logic and web endpoints as standardized tools, allowing AI models to discover, interact with, and execute backend functions through a unified interface. The project distinguishes itself by automatically converting application request and response models into protocol-compliant schemas, ensuring that AI agents receive accurate functional context. It supports a transport-agnostic architecture that facilitates real-time bidirect

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

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