Open Source JavaScript API Clients

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.

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.

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.

Postcat is a free, open-source API development and testing application designed for developers and software teams. It provides a unified interface for creating, organizing, documenting, and testing application programming interfaces. The software supports HTTP REST and WebSocket protocols for communicating with backend services. Users can configure requests, inspect responses, and manage API environments and global variables. Its extensible plugin system allows additional tools and functionality to be incorporated into development workflows. Postcat also provides API design, documentation, collaboration, and sharing capabilities. Available for Windows, macOS, Linux, and web browsers, the project has entered maintenance suspension and no longer receives regular feature updates or security fixes.

Resonance is a free, open-source API client designed for developing, testing, and debugging web services without cloud accounts. It supports REST, GraphQL, gRPC, WebSocket, Server-Sent Events, and MQTT protocols. Users can create requests, inspect responses, and organize API collections in human-readable YAML files. The software provides authentication tools, environment variables, and secure credential storage through operating system keychains. It includes request scripting, automated tests, mock servers, and schema validation. Developers can import existing API specifications and generate client code in multiple languages. Built with Tauri and Rust, Resonance offers a lightweight, local-first alternative to conventional API testing platforms.

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.

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.

GitHub REST API client for JavaScript. Import the Octokit constructor based on your platform. Instantiate your octokit API. All options are optional, but authentication is strongly encouraged. API Previews can be enabled globally by setting the previews option. They can be set per-request as well. A default time zone can be enabled by setting the timeZone option. In order to use Octokit with GitHub Enterprise, set the baseUrl option. Most of GitHub’s REST API endpoints have matching methods. All endpoint methods are asynchronous, in order to use await in the code examples, we wrap them into an anonymous async function. Authentication is optional for some REST API endpoints accessing public data, but is required for GraphQL queries. Using authentication also increases your API rate limit.