Open Source BSD API Gateways

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

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.

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

Grafbase is an open-source GraphQL federation gateway and API platform designed to unify multiple backend services and data sources into a single, high-performance GraphQL interface. The project provides a Rust-based gateway that acts as the central layer for composing and managing distributed APIs, particularly in microservice architectures where data may come from many independent systems. By supporting GraphQL federation standards, the platform enables teams to combine multiple subgraphs or services into a unified schema that clients can query as a single endpoint. Grafbase is designed for large-scale production environments, emphasizing high throughput, low latency, and efficient resource usage through its Rust implementation. The system also includes tools for schema governance, API lifecycle management, and collaboration workflows, helping engineering teams safely evolve complex APIs over time.

HSBC API is a custom set of PHP classes to build, submit and process all the transaction/XML data between your shopping cart and the HSBC XML API gateway. Allows complete transaction building and processing for any HSBC e-commerce customers

KrakenD is more than a typical proxy that forwards clients to backend services, but a powerful engine that can transform, aggregate or remove data from your own or third party services. KrakenD also implements the Backend for Frontend and Micro-frontends patterns to eliminate the necessity of dealing with multiple REST services, isolating clients from the micro-service implementation details. KrakenD's stateless architecture and performance-first approach for every internal component beat any API Gateway in the market. Our customers with massive usage face the networking limits while KrakenD still keeps a low consumption of resources. But don't take our word for granted, do your own benchmarks. All KrakenD endpoint configuration is stored in a plain text .json configuration file. You can edit this file by hand or design your API interface visually using the KrakenDesigner.

Nessconnect is a GUI, CLI and API client for Nessus and Nessus compatible servers. With an improved user interface, it provides local session management, scan templates, report generation through XSLT, charts and graphs, and vulnerability trending.

The Java SDK for the Yahoo! EWS API makes it easy to build Search Marketing tools with Java to programmatically access and manage Yahoo! Search Marketing accounts. The client library is a single jar file that contains all that you need to access EWS API.

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

This library helps you easily create a Python application with WhatsApp API. https://green-api.com/en/