Open Source Developer Tools Projects

Utilities and tooling to improve developer productivity including IDEs, linters, debuggers, and build tools.

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Hoppscotch

Open source API development ecosystem - https://hoppscotch.io (open-source alternative to Postman, Insomnia)

Alternative to:

Postman

HTTPie

🚀 HTTPie Desktop — cross-platform API testing client for humans. Painlessly test REST, GraphQL, and HTTP APIs.

Alternative to:

Postman

Scalar

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

Alternative to:

Postman

Bruno

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

Alternative to:

Postman

Insomnia

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

Alternative to:

Postman

Lightpanda

A headless browser built from scratch in Zig, optimised for AI agents and automation with 9x less memory and 11x faster execution than Chrome.

Alternative to:

Playwright

Yaak

The most intuitive desktop API client. Organize and execute REST, GraphQL, WebSockets, Server Sent Events, and gRPC 🦬

Alternative to:

Postman

OpenCode

OpenCode is an open source agent that helps you write code in your terminal, IDE, or desktop.

Alternative to:

Claude Code