Open-source alternatives to Openapi Typescript Codegen

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

bknd is a self-hosted backend-as-a-service platform and serverless backend framework that provides an integrated environment for managing databases, authentication, and file storage. It functions as a headless CMS and a portable API engine designed to run across various JavaScript runtimes, including Node.js, Bun, Cloudflare Workers, and AWS Lambda. The project distinguishes itself through a combination of schema-driven API generation and a built-in database management UI. It enables the definition of data structures either programmatically via a type-safe API or visually through an administr

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

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

Fern is a toolset for managing API specifications, generating type-safe client libraries, and producing hosted developer documentation. It provides a utility for validating, transforming, and exporting API definitions into standardized OpenAPI formats, serving as a system to maintain a consistent source of truth for API designs. The project differentiates itself through an automated SDK distribution pipeline that publishes generated libraries to package managers such as npm, PyPI, Maven, and NuGet. It also includes an AI-powered search assistant trained on API and SDK specifications to answer

This project is a command-line tool that automates the creation of type-safe TypeScript HTTP clients directly from OpenAPI specifications. By transforming service definitions into structured source code, it ensures end-to-end type synchronization and enforces runtime data integrity across network boundaries. The generator distinguishes itself by mapping OpenAPI data structures into Zod validation schemas, allowing for consistent schema-driven type mapping and response validation. It supports deduplicated source synthesis to minimize redundancy in the generated output and provides template cus

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

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

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

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

This project is a command-line schema-to-code converter designed to transform diverse data specifications into type-safe Python data structures. It functions as a generator for Pydantic models, dataclasses, and typed dictionaries, enabling developers to maintain synchronization between evolving data contracts and application code. By parsing formats such as JSON Schema, OpenAPI, AsyncAPI, Protobuf, and Avro, the tool automates the creation of native classes that reflect the constraints and metadata defined in the source specifications. The generator distinguishes itself through a highly confi

RAML is a declarative YAML-based specification language used for modeling RESTful interfaces and data structures. It functions as a contract-first API framework and modeling standard, establishing a formal agreement for service communication and a single source of truth before implementation begins. The specification enables the automation of functional mock servers and the generation of language-specific client SDKs directly from the definition files. It supports a modular approach to API design through the use of external libraries, overlays for extending contracts, and reusable traits and

Axios is an isomorphic, promise-based HTTP client designed for making asynchronous network requests across different JavaScript execution environments, including the browser and Node.js. It functions as a JSON API client that serializes JavaScript objects into JSON and parses server responses into structured data. The project features a system for managing reusable client instances with shared configurations, such as base URLs and default settings. It includes a mechanism for intercepting outgoing requests and incoming responses globally, allowing data to be transformed before it reaches the

Jeesite is a full-stack low-code development framework designed for building enterprise administrative portals using Spring Boot, MyBatis, and Vue. It functions as a comprehensive platform for creating administrative dashboards with integrated role-based access control and organizational data permission systems. The framework distinguishes itself through a combination of automated CRUD code generation and an integrated RAG platform that connects large language models to enterprise data via vector stores. It further incorporates a BPMN-based workflow engine to automate complex business process

This project is a type-safe GraphQL client generator and TypeScript schema compiler. It transforms GraphQL schema definitions and operation documents into static TypeScript types to ensure compile-time validation and data consistency between an API and a frontend application. The system functions as a customizable GraphQL plugin framework. It uses a plugin-based architecture and a custom pipeline to generate tailored API clients and request functions, eliminating the need for manual type declarations. The project covers GraphQL client automation, type generation, and workflow optimization. I

Refit is a type-safe REST client for .NET that transforms API definitions into live interfaces. It functions as an automatic API proxy generator, allowing developers to define endpoints as interfaces to eliminate manual HTTP request boilerplate. The library is designed for compatibility with ahead-of-time compilation and trimmed binaries, utilizing build-time source generation to ensure support for native AoT deployments. The project covers a broad range of API integration capabilities, including attribute-driven request composition, automatic JSON deserialization, and request header managem

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

Sourcery is a code generation tool for Swift that automates the production of repetitive boilerplate and protocol conformance. It functions as a template engine that scans source files to generate structural code, such as Codable, Equatable, and Hashable implementations, based on marker protocols and static analysis. The project provides a specialized mocking framework that creates mock objects for protocols to track function calls and capture arguments during testing. It also includes utilities for generating struct lenses, enum case collections, and precise property-level test diffs. The s

Kiota is a multi-language SDK generator and REST API client orchestrator that transforms OpenAPI descriptions into strongly typed client libraries. It provides a framework for managing API specifications and generating typed interfaces to eliminate manual boilerplate development. The project utilizes a template-driven source emission system to map API specifications to native language types. It ensures consistency across environments using lock-file version syncing and organizes API endpoints into a nested object structure based on the hierarchical mapping of URI paths. The toolset includes

Scalar is a platform for building and managing API specifications, focusing on OpenAPI and AsyncAPI standards. It provides tools to generate interactive API references with embedded testing interfaces, create mock servers for pre-implementation testing, and build offline-first API clients that sync with backend frameworks. The platform also supports version upgrades of specifications to maintain compatibility and includes command-line utilities for local development and document management. The project distinguishes itself through automated release workflows that generate changelogs and publi

This project is a command-line tool and template-based scaffolding engine that transforms API interface specifications into functional client libraries and server stubs. By automating the creation of type-safe SDKs and boilerplate code, it bridges the gap between service definitions and implementation, allowing developers to maintain synchronized codebases across many programming languages. The tool distinguishes itself through a portable execution model that utilizes containerized build isolation to ensure identical output regardless of the host environment. It features a modular, plugin-bas

xboot is a full-stack development platform and low-code application framework pairing a Spring Boot backend with a Vue.js frontend. It provides a scaffolding environment for enterprise application development, focusing on rapid development through automated code generation for business logic, interfaces, and data operations. The platform features a visual workflow orchestrator for modeling and executing multi-step business process automation and an identity and access manager implementing OAuth2, single sign-on, and social login integration. It includes a distributed system utility suite that

This project is a project scaffolding engine and template-based code generator. It provides a modular project template library and a command-line tool designed to generate standardized directory structures and configuration files from reusable skeletons. The system uses variable injection and custom delimiters to render project skeletons into concrete files. It includes a mechanism for synchronizing shared template collections via version control repositories and a utility for uploading generated files and secrets to remote hosts using secure shell protocols. The tool covers automated projec

docker-gen is a configuration generator that renders text templates into files using metadata retrieved from Docker containers. It functions as a service discovery tool and template-based orchestrator, mapping container state and environment variables to specific destination paths on a host machine's local storage. The tool automates the update of reverse proxy and service discovery settings in real time as containers are started, stopped, or renamed. It employs sequential template processing and helper functions to filter and sort container data, ensuring stable and consistent configuration

xo is a tool for generating type-safe Go models and query execution code from SQL database schemas and queries. It functions as a multi-dialect SQL tool supporting PostgreSQL, MySQL, SQLite, Oracle, and Microsoft SQL Server to produce idiomatic source code. The project uses a template-based generation system, allowing the structure and logic of the generated database source code to be defined through customizable text templates. It also includes a database schema visualizer that analyzes table relationships and definitions to create visual diagrams and structured documentation. The tool's ca

oapi-codegen is a suite of generators that converts OpenAPI 3 specifications into type-safe Go client libraries, server boilerplate, and data models. It provides tools for producing production-ready HTTP clients and server-side interfaces to ensure that Go implementations remain compliant with defined API contracts. The tool supports server generation across various web frameworks and allows for extensive customization via template overrides, specification overlays, and custom type definition mappings. It handles complex API requirements through external reference resolution to organize code

The AWS SDK for Go is a software development kit and cloud infrastructure library used to programmatically interact with AWS cloud services. It provides a programmatic interface for authenticating requests, executing operations against regional endpoints, and automating the creation and management of cloud resources. The toolkit utilizes model-driven code generation to create service clients and employs a session-based configuration system to share credentials and global settings across those clients. It implements signature-based request authentication to verify identity and integrity throug