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

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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: 454 This Week
    Last Update:
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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: 49 This Week
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  • 3
    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: 47 This Week
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  • 4
    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: 34 This Week
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  • 5
    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: 21 This Week
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  • 6
    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: 5 This Week
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  • 7
    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: 4 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: 2 This Week
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  • 9
    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: 2 This Week
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  • 10
    OpenAI PHP Client

    OpenAI PHP Client

    OpenAI PHP is a supercharged community-maintained PHP API client

    The openai-php/client library is a PHP client for interacting with OpenAI’s API, enabling developers to integrate OpenAI models into their PHP applications. It simplifies sending API requests to access language models, generating text, processing natural language, and utilizing OpenAI’s advanced features. The library is designed to be easy to use, allowing developers to quickly set up and use OpenAI’s capabilities within their PHP projects.
    Downloads: 2 This Week
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  • 11
    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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  • 12
    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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  • 13
    Posting

    Posting

    The modern API client that lives in your terminal

    Posting is an open-source, terminal-based API client designed for developers who prefer a fast, keyboard-driven workflow. It allows users to create, test, and manage HTTP requests directly from the command line without relying on graphical tools. The interface is highly interactive, offering features like command palettes, jump navigation, and real-time editing for efficient API exploration. Posting supports saving requests in a readable, version-control-friendly format, making it ideal for collaboration and reproducibility. It also includes scripting capabilities, enabling users to run Python code before and after requests to automate workflows. Overall, Posting brings a modern, customizable, and developer-centric API testing experience to the terminal.
    Downloads: 1 This Week
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  • 14
    Swagger Codegen

    Swagger Codegen

    Template-driven engine to generate documentation

    Swagger-Codegen contains a template-driven engine to generate documentation, API clients and server stubs in different languages by parsing your OpenAPI / Swagger definition. 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. If the OpenAPI/Swagger spec is obtained from an untrusted source, please make sure you've reviewed the spec before using Swagger Codegen to generate the API client, server stub or documentation as code injection may occur.
    Downloads: 1 This Week
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  • 15
    Swagger Core

    Swagger Core

    Examples, server integrations for generating Swagger API Specification

    Swagger Core is a Java implementation of the OpenAPI Specification. Current version supports JAX-RS2 (javax and jakarta namespaces). One of the common usage scenarios is to integrate swagger-jaxrs2 into an existing or new JAX-RS based project ("code-first"), to automatically provide and expose its APIs definition, which is kept in sync during the project lifecycle. Such definition can be the base for further processing/consumption, including API documentation (e.g with swagger-ui, API client generation in various languages (e.g with swagger-codegen), custom processing, and so on. Such result is achieved by scanning JAX-RS resources and resolving their operations and used types, (also) processing applied annotations (e.g. Swagger, JAX-RS, Jackson, JAXB, etc.). An extension mechanism allows to further customize and pre/post processing result.
    Downloads: 1 This Week
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  • 16

    email-checker-php-sdk

    PHP SDK to connect with Easy Email Verification API and validate email

    The Email Checker PHP SDK is part of the Easy Email Verification - URL Checker ecosystem, designed to help developers integrate real-time email verification into their PHP applications. It uses the Easy Email Verification API to validate if an email address is real, active, and safe to use. The SDK performs domain and MX record checks, SMTP validation, and detection of disposable or role-based addresses. It provides a lightweight and reliable cURL-based implementation that returns structured JSON responses. This project is officially maintained by Easy Email Verification Ltd. For technical documentation and API reference, visit https://www.easyemailverification.com
    Downloads: 1 This Week
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  • 17
    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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  • 18
    API Dash

    API Dash

    API Dash is a beautiful AI-powered open-source cross-platform

    API Dash is an open-source, cross-platform API client built with Flutter for testing, designing, and exploring APIs. It gives developers a visual interface to create and customize HTTP requests, inspect responses, and organize API work without relying only on command-line tools. The project supports desktop and mobile workflows, making it useful across Windows, macOS, Linux, Android, and iOS-style environments. It also includes AI-powered capabilities and code generation features to help developers move from request testing to implementation faster. API Dash is useful for backend developers, frontend engineers, QA testers, students, and teams that need a clean alternative to heavier proprietary API clients. Its focus is a modern interface, practical request management, response inspection, and portable developer productivity.
    Downloads: 0 This Week
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  • 19
    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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  • 20
    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: 0 This Week
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  • 21
    Curlie

    Curlie

    The power of curl, the ease of use of httpie

    If you like the interface of HTTPie but miss the features of curl, curlie is what you are searching for. Curlie is a frontend to curl that adds the ease of use of httpie, without compromising on features and performance. All curl options are exposed with syntax sugar and output formatting inspired from httpie. When running interactively, curlie provides pretty-printed output for json. To force pretty-printed output, pass --pretty.
    Downloads: 0 This Week
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  • 22
    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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  • 23
    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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  • 24
    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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  • 25
    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: 0 This Week
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