API Client GitHub Repositories (2026) · Open Source Tools

Opensource IDE For Exploring and Testing API's (lightweight alternative to Postman/Insomnia)

Tetiva — desktop API client for HTTP, gRPC, GraphQL and WebSocket (Wails v3 + Vue 3)

A free, open-source developer workspace. Snippets, notes, HTTP requests, calculations, and dev tools in one local-first app.

Use Hugging Face with JavaScript

Open-Source API Development Ecosystem • https://hoppscotch.io • Offline, On-Prem & Cloud • Web, Desktop & CLI • Open-Source Alternative to Postman, Insomnia

OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec (v2, v3)

Scalar is an open-source API platform:　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　🌐 Modern REST API Client　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　📖 Beautiful API References　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　✨ 1st-Class OpenAPI/Swagger Support

The open-source, cross-platform API client for GraphQL, REST, WebSockets, SSE and gRPC. With Cloud, Local and Git storage.

A Fork of Rikkahub with an overhauled UI and feature additions

A fast, keyboard-driven TUI API client & webhook inspector. No cloud, no Electron, 100% local-first.

A lightweight, fully-featured TypeScript SDK for the Shopee Open API v2. Features automatic request signing, pluggable token storage, robust error handling, and 100% endpoint coverage.

Asynchronous Python client for WLED

Terminal API client for HTTP, GraphQL, gRPC, WebSocket and SSE. Plain .http files you can diff and version, with scripted tests, workflows, mocks, recorder, and a CLI runner for CI.

Fast, native API client for REST, gRPC, WebSocket and GraphQL. A local-first Postman alternative written in Go: no Electron, no account, no cloud.

Notion API client SDK, rewritten in Python! (sync + async)

One API for every LLM: 170+ providers through one client, with a Rust core and native bindings for every major language.

A PHP API client class to interact with Ubiquiti's UniFi Controller API

A RWKV management and startup tool, full automation, only 8MB. And provides an interface compatible with the OpenAI API. RWKV is a large language model that is fully open source and available for commercial use.

PHP Curl Class makes it easy to send HTTP requests and integrate with web APIs

Python wrapper for the Mastodon ( https://github.com/mastodon/mastodon/ ) API.