tmenier/Flurl

Hoppscotch is an open-source API development ecosystem, built in TypeScript and licensed under MIT, that serves as a web-based client for interacting with APIs. It offers PWA, desktop, and CLI options via add-ons, positioning itself as an alternative to commercial tools like Postman. It handles a wide range of protocols including HTTP (supporting all standard and custom methods), WebSocket, Server-Sent Events, Socket.IO, MQTT, and GraphQL. Developers can define requests with various authorization types (Basic, Bearer, OAuth 2.0, OIDC), custom headers, and parameters, and craft request bodies in formats like FormData or JSON. The tool includes features like Pre-Request Scripts and Post-Request Tests using JavaScript, environment variables, and organized collections with nested folders for managing API calls. For collaboration, it supports teams with shared collections, role-based access, and workspaces, along with a proxy mode to address CORS issues or access non-HTTPS endpoints. It also provides cloud sync for data across devices and a customizable UI with theming and keyboard shortcuts.

Caddy is an HTTP/1-2-3 web server, written in Go, which provides automatic HTTPS by default, utilizing services like ZeroSSL and Let's Encrypt for public names or a local CA for internal ones. It supports flexible configuration through its native JSON API, a Caddyfile, or various other formats via config adapters. The project highlights a modular architecture for extensibility, runs on multiple platforms without external dependencies, and benefits from Go's memory safety features. The README indicates it has served trillions of requests and managed millions of TLS certificates, scaling to hundreds of thousands of sites in production. Caddy began development in 2014 and was an early adopter of automatic HTTPS by default.

Public APIs is a community-curated GitHub repository listing free, publicly accessible APIs across a wide range of categories, with auth type, HTTPS, and CORS noted for each entry. It's a browsable reference, not a library to install.

Awesome-Selfhosted is a community-maintained GitHub list at awesome-selfhosted/awesome-selfhosted that catalogs Free Software network-service and web-app projects meant for running on a server you control rather than someone else's cloud. Entries are grouped by category, each tagged with a license and a language or deployment option, and the project keeps proprietary alternatives on a separate Non-Free page.