Directory

Open Source Packages

Libraries, frameworks, tools, and SDKs used by the apps in this directory — scored the same way as the apps themselves.

5929 packages

All Packages

96Health
Framework PyPI

pytest

The Python testing framework that makes writing small tests easy and scales to complex functional test suites.

14,543
MIT
Used by 100
91Health
Framework PyPI

FastAPI

A modern, high-performance Python web framework for building APIs with automatic validation, serialization, and interactive docs.

102,676
MIT
Used by 78
95Health
Framework PyPI

aiohttp

Asynchronous HTTP client and server framework for Python's asyncio, covering both API calls and building web/WebSocket services.

16,561
Apache 2.0
Used by 40
95Health
Framework PyPI

Transformers

State-of-the-art pretrained models for text, vision, audio, and multimodal inference and training.

166,736
Apache 2.0
Used by 38
92Health
Framework npm

Docusaurus

React-based static site generator for building fast, maintainable documentation websites.

66,349
MIT
Used by 36
81Health
Framework PyPI

Flask

A lightweight WSGI web framework for Python that scales from a single file to complex applications.

74,802
BSD 3
Used by 28
92Health
Framework npm

NestJS

A progressive Node.js framework for building efficient, scalable, and maintainable server-side applications in TypeScript.

76,743
MIT
Used by 27
89Health
Framework PyPI

Typer

Typer is a Python library for building CLI applications, using type hints to generate arguments, options, validation, help text, and shell completion automatically.

20,033
MIT
Used by 26
87Health
Framework PyPI

Django

The high-level Python web framework that turns database models into secure, working web applications in record time.

91,218
BSD 3
Used by 24
92Health
Framework PyPI

LangChain

The most widely adopted Python framework for building LLM-powered agents and applications

147,170
MIT
Used by 21
94Health
Framework PyPI

Starlette

A lightweight ASGI framework/toolkit for building async web services and apps in Python

12,639
BSD 3
Used by 21
92Health
Framework PyPI

LangGraph

A low-level orchestration framework for building stateful, multi-actor LLM agents as graphs

42,375
MIT
Used by 18
91Health
Framework PyPI

django-rest-framework

The most widely-used toolkit for building Web APIs on top of Django, with serializers, viewsets, and a built-in browsable API.

30,191
BSD 3
Used by 15
88Health
Framework PyPI

FastMCP

The fast, Pythonic framework for building Model Context Protocol servers, clients, and apps

27,913
Apache 2.0
Used by 14
91Health
Framework PyPI

Pydantic AI

A type-safe Python agent framework built by the Pydantic team

20,217
MIT
Used by 14
82Health
Framework Go

Bubble Tea

A Go framework based on The Elm Architecture for building terminal UIs, from simple prompts to full-window, high-performance TUI applications.

45,125
MIT
Used by 13
89Health
Framework PyPI

OpenAI Agents SDK

OpenAI's provider-agnostic Python framework for building multi-agent LLM workflows with tools, guardrails, and tracing.

29,733
MIT
Used by 8
92Health
Framework PyPI

Streamlit

Turn a Python script into a shareable data app in minutes, with no frontend code

45,845
Apache 2.0
Used by 6
92Health
Framework PyPI

Gradio

Build and share machine learning web apps and demos in pure Python.

43,633
Apache 2.0
Used by 6
91Health
Framework npm

Pulumi

Infrastructure as Code in your favorite programming language, powered by a shared multi-language deployment engine.

25,735
Apache 2.0
Used by 6
88Health
Framework PyPI

Deep Agents

The batteries-included agent harness for building long-horizon LLM agents

29,814
MIT
Used by 5
86Health
Framework PyPI

Tornado

Python web framework and asynchronous networking library built for high concurrency

22,179
Apache 2.0
Used by 5
87Health
Framework PyPI

PySpark

Python API for Apache Spark, the unified engine for large-scale distributed data processing

44,074
Apache 2.0
Used by 4
92Health
Framework Go

Fiber

An Express-inspired Go web framework built on Fasthttp for zero-allocation, extreme-performance HTTP servers.

40,185
MIT
Used by 4

Join founders buildingwith open source

Opinionated takes, migration guides, cost-saving tips, and insights from the open source ecosystem.

Subscribe on Substack
Join 750+ subscribers