Open Source API Gateways
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Browse free open source API Gateways and projects for Windows and Linux below. Use the toggles on the left to filter open source API Gateways by OS, license, language, programming language, and project status.
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Train ML Models With SQL You Already KnowBuild and deploy ML models using familiar SQL. Automate data prep with built-in Gemini. Query 1 TB and store 10 GB free monthly.
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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. -
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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. -
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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. -
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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. -
MongoDB Atlas runs apps anywhereMongoDB Atlas gives you the freedom to build and run modern applications anywhere—across AWS, Azure, and Google Cloud. With global availability in over 115 regions, Atlas lets you deploy close to your users, meet compliance needs, and scale with confidence across any geography.
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node-addon-api
Module for using Node-API from C++
node-addon-api is a C++ wrapper module that simplifies the creation of Node.js native addons using the Node-API, promoting ABI stability across different Node.js versions. -
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Yaak
The most intuitive desktop API client
Yaak is a modern desktop API client designed to provide a fast, intuitive, and privacy-focused environment for interacting with APIs across multiple protocols. It supports a wide range of technologies including REST, GraphQL, gRPC, WebSocket, and Server-Sent Events, allowing developers to work with different types of APIs from a single unified interface. The application is built using Tauri, Rust, and React, which contributes to its lightweight footprint, high performance, and cross-platform compatibility. One of its core design principles is being offline-first, meaning that user data, requests, and secrets are stored locally without reliance on cloud services, enhancing both privacy and control. Yaak also emphasizes developer productivity by offering features such as dynamic request templating, debugging tools, and environment-based configuration management. -
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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. -
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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. -
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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. -
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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. -
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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. -
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API Umbrella
Open source API management platform
API Umbrella is an open source API management platform for exposing web service APIs. The basic goal of API Umbrella is to make life easier for both API creators and API consumers. APIs can assume the boring stuff (access control, rate limiting, analytics, etc.) is already taken care if the API is being accessed, so common functionality doesn't need to be implemented in the API code. API Umbrella acts as a layer above your APIs, so your API code doesn't need to be modified to take advantage of the features provided. -
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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. -
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Apex Up
Deploy infinitely scalable serverless apps, APIs and sites
Up deploys infinitely scalable serverless apps, APIs, and static websites in seconds, so you can get back to working on what makes your product unique. Up focuses on deploying “vanilla” HTTP servers so there’s nothing new to learn, just develop with your favorite existing frameworks such as Express, Koa, Django, Golang net/HTTP or others. Up currently supports Node.js, Golang, Python, Java, Crystal, and static sites out of the box. Up is platform-agnostic, supporting AWS Lambda and API Gateway as the first targets, you can think of Up as a self-hosted Heroku-style user experience for a fraction of the price, with security, flexibility, and scalability of AWS, just $ up and you’re done! Up Pro provides additional features for production-ready applications such as encrypted environment variables, error alerting, unlimited team members, unlimited applications, priority email support, and global deployments for $19.99/mo USD. -
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Claudia Bot Builder
Create chat bots for Facebook Messenger, Slack, Amazon Alexa, etc.
Claudia Bot Builder helps developers create and deploy chat-bots for various platforms in minutes to AWS Lambda. It simplifies the messaging workflows, automatically sets up the correct web hooks, and guides you through configuration steps, so that you can focus on important business problems and not have to worry about infrastructure code. This code is enough to operate bots for all supported platforms. Claudia Bot Builder automatically parses the incoming messages into a common format, so you can handle it easily. It also automatically packages the response into the correct message template for the requesting bot, so you do not have to worry about individual bot protocols. Claudia Bot Builder doesn't have a stand-alone http server in the background (such as Express, Hapi, etc.), instead it uses API Gateway and it's not trivial to simulate similar environment locally. Deploy it with --version test to create a separate test environment directly in AWS Lambda. -
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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. -
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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. -
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Flask-Limiter
Rate Limiting extension for Flask
Flask-Limiter provides rate-limiting features to flask applications. It allows configuring various backends to persist the rate limits, which is provided by the limits library. Sponsored by Zuplo - fully-managed API Gateway with rate limiting, authentication, and more. Add rate limiting to your API in minutes, try it at zuplo.com Test it out. The fast endpoint respects the default rate limit while the slow endpoint uses the decorated one. ping has no rate limit associated with it. By adding the extension to your flask application, you can configure various rate limits at different levels (e.g. application wide, per Blueprint, routes, resource etc). To include extra dependencies for a specific storage backend you can add the specific backend name via the extras notation. -
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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. -
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Mangum
AWS Lambda support for ASGI applications
Mangum is an adapter for running ASGI applications in AWS Lambda to handle Function URL, API Gateway, ALB, and Lambda@Edge events. Event handlers for API Gateway HTTP and REST APIs, Application Load Balancer, Function URLs, and CloudFront Lambda@Edge. Compatibility with ASGI application frameworks, such as Starlette, FastAPI, Quart and Django. Support for binary media types and payload compression in API Gateway using GZip or Brotli. Works with existing deployment and configuration tools, including Serverless Framework and AWS SAM. The heart of Mangum is the adapter class. It is a configurable wrapper that allows any ASGI application (or framework) to run in an AWS Lambda deployment. The adapter accepts a number of keyword arguments to configure settings related to logging, HTTP responses, ASGI lifespan, and API Gateway configuration. -
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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. -
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NetSuite PHP API Client
NetSuite PHP API Client with namespaces and autoloading
A PHP API client package for NetSuite, pried from the NetSuite PHP Toolkit and made more consumable for modern PHP application development. All of the classes in the NetSuite\Classes namespace are code provided by NetSuite with a license allowing redistribution. The custom work provided by this library separates these nearly 2,000 classes out into their own files and allows the classes to be installed with composer and accessed using standard autoloading support. It allows configuration to be read from the environment, adds support to log requests and responses and provides a simplified client wrapper class (NetSuiteService). You can alternatively place your config in environment variables. This is helpful in hosted environments where deployment of config files is either not desired or practical. You can find the valid keys in the included .env.example file with sample values. -
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Nodejs Expressjs MongoDB API Project
A boilerplate for REST API Development with Node.js, Express, etc.
A ready-to-use boilerplate for REST API Development with Node.js, Express, and MongoDB. This is a basic API skeleton written in JavaScript ES2015. Very useful to building RESTful web APIs for your front-end platforms like Android, iOS or JavaScript frameworks (Angular, Reactjs, etc). This project will run on NodeJs using MongoDB as a database. I tried to maintain the code structure easily as any beginner can also adopt the flow and start building an API. The project is open for suggestions, Bug reports and pull requests. Basic Authentication (Register/Login with hashed password). Account confirmation with 4 (Changeable) digit OTP. Email helper ready just import and use. JWT Tokens, make requests with a token after login with Authorization header with value Bearer yourToken where yourToken will be returned in Login response. Pre-defined response structures with proper status codes. Included CORS. Book example with CRUD operations. Validations added. -
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Octokit
Ruby toolkit for the GitHub API
API wrappers should reflect the idioms of the language in which they were written. Octokit.rb wraps the GitHub API in a flat API client that follows Ruby conventions and requires little knowledge of REST. Most methods have positional arguments for required input and an options hash for optional parameters, headers, or other options. While most methods return a Resource object or a Boolean, sometimes you may need access to the raw HTTP response headers. Access tokens can be revoked, removing access for only that token without having to change your password everywhere. Access tokens have access scopes that allow for more granular access to API resources. For instance, you can grant a third party access to your gists but not your private repositories. Two-Factor Authentication brings added security to the account by requiring more information to login. -
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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.
