API Clients for Windows

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Browse free open source API Clients and projects for Windows below. Use the toggles on the left to filter open source API Clients by OS, license, language, programming language, and project status.

  • Vibes don’t ship, Retool does Icon
    Vibes don’t ship, Retool does

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  • 1
    gSOAP Toolkit

    gSOAP Toolkit

    Development toolkit for Web Services and XML data bindings for C & C++

    The gSOAP toolkit is an extensive suite of portable C and C++ software to develop XML Web services with powerful type-safe XML data bindings. Easy-to-use code-generator tools allow you to directly integrate XML data in C and C++. Serializes native application data in XML. Includes WSDL/XSD schema binding and auto-coding tools, stub/skeleton compiler, Web server integration with Apache module and IIS extension, high-performance XML processing with schema validation, fast MIME/MTOM streaming, SOAP and REST Web API development, WS-* protocols (WS-Security, WS-Policy, WS-ReliableMessaging, etc), XML-RPC and JSON. Licensed under GPLv2. Visit the developer center with guides, tutorials, and examples at www.genivia.com/dev.html The documentation of the toolkit, libraries, plugins and more is available at www.genivia.com/docs.html Commercial-use licenses and expert technical support services are available at competitive pricing levels, please visit www.genivia.com/products.html
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    Downloads: 580 This Week
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  • 2
    Bruno

    Bruno

    Opensource IDE For Exploring and Testing Api's

    Bruno is a Fast and Git-Friendly Opensource API client, aimed at revolutionizing the status quo represented by Postman, Insomnia, and similar tools out there. Bruno stores your collections directly in a folder on your filesystem. We use a plain text markup language, Bru, to save information about API requests. You can use git or any version control of your choice to collaborate over your API collections. Bruno is offline only. There are no plans to add cloud-sync to Bruno, ever. We value your data privacy and believe it should stay on your device.
    Downloads: 114 This Week
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  • 3
    Swagger UI

    Swagger UI

    HTML, JavaScript, and CSS assets that generate Swagger documentation

    Swagger UI is a collection of HTML, JavaScript, and CSS assets that dynamically generate beautiful documentation from a Swagger-compliant API. Simplify API development for users, teams, and enterprises with the Swagger open source and professional toolset. Find out how Swagger can help you design and document your APIs at scale. The power of Swagger tools starts with the OpenAPI Specification — the industry standard for RESTful API design. Individual tools to create, update and share OpenAPI definitions with consumers. SwaggerHub is the platform solution to support OpenAPI workflows at scale. Swagger open source and pro tools have helped millions of API developers, teams, and organizations deliver great APIs. Swagger offers the most powerful and easiest to use tools to take full advantage of the OpenAPI Specification.
    Downloads: 70 This Week
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  • 4
    Insomnia API Client

    Insomnia API Client

    The open-source, cross-platform API client for GraphQL

    Insomnia is an open-source, cross-platform API client for GraphQL, REST, and gRPC. Deliver high-quality APIs through standards and collaboration with the Insomnia API design platform. There is a reason developers love Insomnia. With our streamlined API client, you can quickly and easily send REST, SOAP, GraphQL, and GRPC requests directly within Insomnia. Accelerate your teams through spec-driven design-first API development. Catch issues earlier, centralize standards, and adopt an API workflow that works with your existing tools. Automate manual API tests and integrate with your CI/CD process to build out an API testing pipeline using Insomnia Unit Tests and Inso, the Insomnia CLI. Connect directly to Git providers to always be in sync with design changes and enable a GitOps pipeline with Inso, the Insomnia CLI tool.
    Downloads: 49 This Week
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  • Atera all-in-one platform IT management software with AI agents Icon
    Atera all-in-one platform IT management software with AI agents

    Ideal for internal IT departments or managed service providers (MSPs)

    Atera’s AI agents don’t just assist, they act. From detection to resolution, they handle incidents and requests instantly, taking your IT management from automated to autonomous.
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  • 5
    Thunder Client

    Thunder Client

    Thunder Client is a lightweight Rest API Client Extension for VS Code

    Thunder Client is a lightweight Rest API Client Extension for Visual Studio Code, hand-crafted by Ranga Vadhineni with simple and clean design. The source code is not open source. You can report any bugs or feature requests here. Lightweight Rest API Client for VS Code. Simple & Easy to use UI. Supports Collections and Environment variables. Scriptless Testing: Test API response easily with GUI based interface. Themes: The extension supports VS Code themes. Offline & Local Storage: Works offline and saves all the requests data locally on your device. Git Sync: Save requests data in current workspace. Thunder Client is built with Javascript, Typescript, Flexbox, Ace Editor, Got. Enable this setting when you'd like to save requests data in the current workspace.
    Downloads: 30 This Week
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  • 6
    Firecamp

    Firecamp

    OpenSource Postman Alternative. The developer-first API devtool

    Firecamp is a DX-first API development platform that helps developers design, develop, test, and document their APIs effortlessly. With a user-friendly interface and a range of powerful features, Firecamp streamlines the API development workflow and enhances collaboration among team members.
    Downloads: 3 This Week
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  • 7
    Godo

    Godo

    DigitalOcean Go API client

    Godo is a Go client library for accessing the DigitalOcean V2 API. Create a new DigitalOcean client, then use the exposed services to access different parts of the DigitalOcean API. Currently, Personal Access Token (PAT) is the only method of authenticating with the API. You can manage your tokens at the DigitalOcean Control Panel Applications Page. If you need to provide a context.Context to your new client, you should use godo.NewClient to manually construct a client instead. If a list of items is paginated by the API, you must request pages individually. Some endpoints offer token based pagination. For example, to fetch all Registry Repositories. Each version of the client is tagged and the version is updated accordingly.
    Downloads: 3 This Week
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  • 8
    Google API PHP Client

    Google API PHP Client

    A PHP client library for accessing Google APIs

    The Google API PHP Client is an official PHP client library for accessing Google APIs such as Gmail, Calendar, Drive, YouTube, and more. It handles OAuth 2.0 authentication, RESTful API calls, and JSON parsing, making it easier for PHP applications to interact with Google’s ecosystem.
    Downloads: 3 This Week
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  • 9
    RestSharp

    RestSharp

    Simple REST and HTTP API Client for .NET

    RestSharp is probably the most popular HTTP client library for .NET. Featuring automatic serialization and deserialization, request and response type detection, variety of authentications and other useful features, it is being used by hundreds of thousands of projects. RestSharp passed over 32 million downloads on NuGet, with average daily download count of 10,000. It's being used by many popular OSS projects, including Roslyn and Swagger. The main purpose of RestSharp is to make synchronous and asynchronous calls to remote resources over HTTP. As the name suggests, the main audience of RestSharp are developers who use REST APIs. However, RestSharp can call any API over HTTP (but not HTTP/2), as long as you have the resource URI and request parameters that you want to send comply with W3C HTTP standards. RestSharp can take care of serializing the request body to JSON or XML and deserialize the response. It can also form a valid request URI based on different parameter kinds.
    Downloads: 2 This Week
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  • Reach Your Audience with Rise Vision, the #1 Cloud Digital Signage Software Solution Icon
    Reach Your Audience with Rise Vision, the #1 Cloud Digital Signage Software Solution

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  • 10
    ASP.NET Minimal APIs Made Easy

    ASP.NET Minimal APIs Made Easy

    A light-weight REST API development framework for ASP.Net 6

    It nudges you towards the REPR Design Pattern (Request-Endpoint-Response) for convenient & maintainable endpoint creation with virtually no boilerplate. Performance is on par with Minimal APIs. It's faster, uses less memory and does around 45k more requests per second than a MVC Controller in our benchmarks. Convenient business logic validation & error responses. Easy access to environment & configuration settings. Supports policy/permission/role/claim based security. In-process pub/sub event notifications (with auto discovery). Declarative security policy building (within each endpoint). Easy Server-Sent-Events for real-time data streaming. Supports any IOC container compatible with ASP.NET. Convenient integration testing (route-less & strongly-typed). Constructor & property injection of endpoint dependencies. Built-in uncaught exception handler. Easy model binding from route/query/json body/claims/forms/headers. Supports swagger/serilog/etc.
    Downloads: 1 This Week
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  • 11
    OpenAI-Java

    OpenAI-Java

    OpenAI Api Client in Java

    OpenAI-Java is the official Java client library provided by OpenAI for interacting with the OpenAI API. It is designed to make it easier for Java applications to call endpoints like chat completions, embeddings, function calling, streaming, and other model services using idiomatic Java patterns. You configure the client (often via environment variables or system properties), then build parameter objects (e.g. ChatCompletionCreateParams) and invoke methods like client.chat().completions().create(...) to send requests in a type-safe way. The library also supports streaming APIs, where the response arrives in chunks, using helpers like ChatCompletionAccumulator to accumulate partial responses into a full object. For complex use cases (e.g. structured outputs, function calling), it provides schema support, JSON annotations, and schema validation.
    Downloads: 1 This Week
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  • 12
    OpenAPI Generator

    OpenAPI Generator

    OpenAPI Generator allows generation of API client libraries

    With 50+ client generators, you can easily generate code to interact with any server which exposes an OpenAPI document. Maintainers of APIs may also automatically generate and distribute clients as part of official SDKs. Each client supports different options and features, but all templates can be replaced with your own Mustache-based templates. Getting started with server development can be tough, especially if you're evaluating technologies. We can reduce the burden when you bring your own OpenAPI document. Some generators support Inversion of Control, allowing you to iterate on design via your OpenAPI document without worrying about blowing away your entire domain layer when you regenerate code. Ever wanted to iteratively design a MySQL database, but writing table declarations was too tedious? OpenAPI documents allow you to convert the metadata about your API into some other format.
    Downloads: 1 This Week
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  • 13
    PHP GitHub API

    PHP GitHub API

    A simple PHP GitHub API client, Object Oriented, tested and documented

    A simple PHP GitHub API client, Object Oriented, tested and documented. Uses GitHub API v3 & supports GitHub API v4. The object API (v3) is very similar to the RESTful API. Object Oriented wrapper for GitHub API, written with PHP. Light and fast thanks to lazy loading of API classes. Extensively tested and documented. We are decoupled from any HTTP messaging client with help by HTTPlug. To integrate this library in laravel Graham Campbell created graham-campbell/github. See the installation instructions to get started in laravel.
    Downloads: 1 This Week
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  • 14
    hug

    hug

    Embrace the APIs of the future. For developing APIs

    hug aims to make developing Python-driven APIs as simple as possible, but no simpler. As a result, it drastically simplifies Python API development. Make developing a Python-driven API as succinct as a written definition. The framework should encourage code that self-documents. It should be fast. A developer should never feel the need to look somewhere else for performance reasons. Writing tests for APIs written on-top of hug should be easy and intuitive. Magic done once, in an API framework, is better than pushing the problem set to the user of the API framework. Be the basis for next-generation Python APIs, embracing the latest technology.
    Downloads: 1 This Week
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  • 15
    API Blueprint

    API Blueprint

    High-level API design language for web APIs

    API Blueprint. A powerful high-level API description language for web APIs. API Blueprint is simple and accessible to everybody involved in the API lifecycle. Its syntax is concise yet expressive. With API Blueprint you can quickly design and prototype APIs to be created or document and test already deployed mission-critical APIs. API Blueprint is built to encourage dialogue and collaboration between project stakeholders, developers and customers at any point in the API lifecycle. At the same time, the API Blueprint tools provide the support to achieve the goals be it API development, governance or delivery. API Blueprint is completely open sourced under the MIT license. Its future is transparent and open. API Blueprint doesn't need a closed work group. Instead it uses the RFC process similar to Rust language or Django Enhancement Proposal RFC processes.
    Downloads: 0 This Week
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  • 16
    The Java SDK for the APT from Yahoo! (http://apt.yahoo.com) API makes it easy to build Search Marketing tools to access and manage APT accounts. Without any pre-knowledge of Axis or SOAP, you can access the APT Web Services as easy as normal Java classes
    Downloads: 0 This Week
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  • 17
    Bert Client

    Bert Client

    Simple and Easy-to-Use REST API client for server developers.

    Bert Client is a standalone software for Windows that allows you to quickly and easily test REST API calls. It is an alternative to more complex tools like Postman, but is designed to be simple and straightforward, allowing you to make adhoc POST and GET requests and receive the response in a straightforward way. Bert Client is perfect for developers who want a lightweight and easy-to-use tool for testing their APIs. With Bert Client, you can quickly test your API endpoints without having to worry about setting up complex configurations or dealing with a steep learning curve. Bert Client supports sending requests with an Authorization token, making it easy to test APIs that require authentication. The response from the API is displayed in a user-friendly format, making it easy to see the results of your API calls.
    Downloads: 0 This Week
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  • 18
    Db Api client is a simple Python DB Api v2.0 client. It shows some information about database, tables, table\'s description. Db Api Client provides sql queries executing, shows results, and exports to some formats (html, csv).
    Downloads: 0 This Week
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  • 19
    DataLoader

    DataLoader

    Generic utility to use with an application's data fetching layer

    DataLoader is a generic utility to be used as part of your application's data fetching layer to provide a simplified and consistent API over various remote data sources such as databases or web services via batching and caching. A port of the "Loader" API originally developed by @schrockn at Facebook in 2010 as a simplifying force to coalesce the sundry key-value store back-end APIs which existed at the time. At Facebook, "Loader" became one of the implementation details of the "Ent" framework, a privacy-aware data entity loading and caching layer within web server product code. This ultimately became the underpinning for Facebook's GraphQL server implementation and type definitions. DataLoader is a simplified version of this original idea implemented in JavaScript for Node.js services. DataLoader is often used when implementing a graphql-js service, though it is also broadly useful in other situations.
    Downloads: 0 This Week
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  • 20
    EasyWeChat

    EasyWeChat

    PHP SDK for integrating with WeChat’s APIs

    EasyWeChat is a PHP SDK for integrating with WeChat’s APIs. It simplifies development for public accounts, mini programs, enterprise WeChat, and payment integration. EasyWeChat abstracts complex API calls into intuitive PHP methods, making it easier to build WeChat-based applications and services.
    Downloads: 0 This Week
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  • 21
    Google APIs Node.js Client

    Google APIs Node.js Client

    Google's supported Node.js client library

    Google's supported Node.js client library for accessing Google APIs. Support for authorization and authentication with OAuth 2.0, API Keys and JWT (Service Tokens) is included. The full list of supported APIs can be found on the Google APIs Explorer. The API endpoints are automatically generated, so if the API is not in the list, it is currently not supported by this API client library. These client libraries are supported by Google. However, these libraries are considered complete and are in maintenance mode. This means that we will address critical bugs and security issues but will not add any new features. For Google Cloud Platform APIs, we recommend using google-cloud-node which is under active development. This library supports the maintenance LTS, active LTS, and current release of node.js.
    Downloads: 0 This Week
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  • 22
    Got

    Got

    Human-friendly and powerful HTTP request library for Node.js

    Got implements RFC 7234 compliant HTTP caching which works out of the box in-memory and is easily pluggable with a wide range of storage adapters. Got uses Keyv internally to support a wide range of storage adapters. For something more scalable you could use an official Keyv storage adapter. Hooks allow modifications during the request lifecycle. Hook functions may be async and are run serially. Got will make no further changes to the request before it is sent. This is especially useful in conjunction with got.extend() when you want to create an API client that, for example, uses HMAC-signing. You can override the request function by returning a ClientRequest-like instance or a IncomingMessage-like instance. This is very useful when creating a custom cache mechanism. The response object will typically be a Node.js HTTP response stream, however, if returned from the cache it will be a response-like object which behaves in the same way.
    Downloads: 0 This Week
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  • 23
    Hasura GraphQL Engine

    Hasura GraphQL Engine

    Blazing fast, instant realtime GraphQL APIs on your DB

    Hasura is an open-source product that accelerates API development by 10x by giving you GraphQL or REST APIs with built-in authorization on your data, instantly. Run Hasura, locally or in the cloud, and connect it to your new or existing databases to instantly get a production-grade GraphQL API. Developers and architects love Hasura because it takes no time to get started, doesn’t need them to be a GraphQL expert upfront, and saves their teams months of recurring effort in building, shipping, and maintaining their APIs. Hasura’s built-in RLS style authorization engine allows you to conveniently specify authorization rules at a model level, and safely expose the GraphQL API to developers inside or outside your organization. Hasura’s authz engine is enabling agile teams in fast-growing startups as well as powering mission-critical data access in highly regulated environments such as Fortune 500 healthcare, financial services and US federal agencies.
    Downloads: 0 This Week
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  • 24
    Hoppscotch

    Hoppscotch

    Open source API development ecosystem

    Lightweight, crafted with minimalistic UI design. Fast, send requests and get/copy responses in real-time. Retrieve response headers identical to those of a GET request, but without the response body. Establishes a tunnel to the server identified by the target resource. Describe the communication options for the target resource. Performs a message loop-back test along the path to the target resource. Some APIs use custom request methods such as LIST. Type in your custom methods. Choose a theme, System (default), Light, Dark, and Black. Choose accent color, Green (default), Teal, Blue, Indigo, Purple, Yellow, Orange, Red, and Pink. Distraction-free Zen mode. Receive a stream of updates from a server over an HTTP connection without resorting to polling. Request entries are synced with cloud / local session storage to restore with a single click. Keep your API requests organized with collections and folders. Reuse them with a single click.
    Downloads: 0 This Week
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  • 25
    Microsoft Kiota

    Microsoft Kiota

    OpenAPI based HTTP Client code generator

    Microsoft Kiota is an open-source tool that generates client libraries from OpenAPI descriptions, making it easier to interact with RESTful APIs. It is designed to work seamlessly with Microsoft Graph and other API ecosystems, providing strongly typed SDKs in multiple programming languages. Kiota simplifies API consumption by automating the creation of client libraries, reducing the manual effort needed to integrate with APIs.
    Downloads: 0 This Week
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