Open Source Tools

Console for mobile browsers

Open-source mobile web console that embeds a full developer toolkit into any mobile browser. Provides console, element inspection, network monitor, resource viewer, performance timing, and JavaScript execution on devices that lack native DevTools. The de facto standard for debugging responsive layouts, mobile-specific JavaScript errors, and production issues on phones — loaded with a single script tag or a browser extension.

Community fork of Codex CLI with Auto Drive, browser integration, and multi-agents

Open-source terminal coding agent (npm `@just-every/code`) — a substantive community fork of OpenAI's Codex CLI adding Auto Drive orchestration, browser/CDP integration, multi-agent commands, theming, and Auto Review, while staying upstream-compatible.

Agent harness performance system with 30+ agents and 136 skills

Everything Claude Code is a comprehensive agent harness performance optimization system providing 30 specialized agents, 136 skills, 60 commands, and automated hook workflows for AI-assisted development. Born from an Anthropic hackathon winner and evolved over 10+ months of intensive daily use, it works across Claude Code, Codex, Cursor, and OpenCode with built-in security scanning via AgentShield, continuous learning, and research-first development patterns.

Virtual whiteboard for sketching

Open-source virtual whiteboard for creating hand-drawn style diagrams, wireframes, and sketches in the browser. Features real-time collaboration, shape libraries, infinite canvas, text support, arrow connectors, and export to PNG/SVG. The hand-drawn aesthetic makes diagrams feel informal and approachable. Works offline as a PWA. Embeddable in Notion, Obsidian, and other tools. Used extensively for architecture diagrams, brainstorming, and technical communication. 95K+ GitHub stars.

PyTorch on-device AI for mobile and edge devices

ExecuTorch is PyTorch's official solution for deploying AI models on mobile, embedded, and edge devices. It features a 50KB base runtime, 12+ hardware backends including Apple CoreML, Qualcomm QNN, ARM, and Vulkan, and native PyTorch export without format conversions. Powers Meta's on-device AI across Instagram, WhatsApp, Quest 3, and Ray-Ban Smart Glasses, supporting LLMs, vision, speech, and multimodal models.

MCP gateway and integration catalog for AI agents

Executor is an MIT-licensed integration layer and MCP gateway for AI agents. It gives Claude Code, Cursor, Codex, and other MCP-speaking clients one endpoint for connected OpenAPI specs, GraphQL APIs, MCP servers, Google Discovery sources, and custom JavaScript tools, with local, cloud, and self-hosted deployment options for teams centralizing tool access.

Modular AI prompt framework for everyday tasks

Fabric is an open-source framework that organizes AI prompts into reusable patterns for solving everyday tasks like summarizing content, explaining code, extracting insights from videos, and generating social media posts. Written in Go with support for 20+ AI providers including OpenAI, Claude, Gemini, and Ollama, it runs from the command line and can serve as a REST API. With 40,000+ GitHub stars, Fabric bridges the gap between AI capabilities and practical workflow automation.

Python toolkit for assessing and mitigating ML model fairness issues

Fairlearn is a Microsoft-backed open-source Python toolkit that helps developers assess and improve the fairness of machine learning models. It provides metrics for measuring disparity across groups defined by sensitive features, mitigation algorithms that reduce unfairness while maintaining model performance, and an interactive visualization dashboard for exploring fairness-accuracy trade-offs. Integrated with scikit-learn and Azure ML's Responsible AI dashboard.

Cloud native runtime security for Kubernetes

Falco is a CNCF graduated open-source runtime security tool that detects unexpected behavior and threats across containers, Kubernetes, and cloud workloads in real time. Originally created by Sysdig, Falco monitors Linux kernel syscalls using eBPF and applies customizable detection rules to alert on malicious activity like container escapes, cryptojacking, unauthorized file access, and anomalous network connections. It supports 50+ alert output channels including SIEM integration.

Zero-config conversion of FastAPI endpoints into MCP tools

FastAPI-MCP automatically converts existing FastAPI endpoints into Model Context Protocol tools with zero configuration. With 11,700+ GitHub stars, it is the most popular MCP integration layer, enabling thousands of FastAPI developers to make their APIs accessible to AI agents like Cursor and Claude through the MCP standard.

Python web framework with HTMX, no JavaScript needed

FastHTML is an open-source Python web framework by Answer.AI that renders HTML directly from Python functions using HTMX. It eliminates the JavaScript build step entirely, letting developers create interactive web apps with pure Python. FastHTML is designed for AI demo apps, admin tools, and internal tooling where full-stack simplicity matters more than SPA complexity. Built by Jeremy Howard's team.

Open-source feature store for machine learning

Feast is an open-source feature store that manages and serves ML features for both training and online inference. It prevents training-serving skew by providing consistent feature access across offline and real-time environments. Feast supports batch materialization from data warehouses, real-time feature retrieval, on-demand transformations, and integrates with major data platforms including BigQuery, Snowflake, Redshift, and DynamoDB.

Open-source toolkit for curating datasets and evaluating visual AI models

FiftyOne is an open-source Python toolkit from Voxel51 for building high-quality datasets and better computer-vision and multimodal AI models. It pairs a browser-based visualization App with programmatic dataset curation, embeddings, similarity search, and model-evaluation workflows.

Turn a Figma design system into a programmable API for AI assistants

Figma Console MCP is open-source design-system infrastructure that exposes Figma to AI assistants through MCP. It supports structured extraction, design creation and editing, debugging, accessibility audits, and bidirectional design-token workflows across local, remote read-only, and paired cloud modes; it is not a generic one-click Figma-to-code exporter.

AI QA agent specialized for mobile apps

FinalRun is a specialized AI QA agent for mobile applications that automates testing of complex mobile gestures and flows on both iOS and Android platforms. It addresses the specific mobile QA gap that generic web-testing tools miss, handling touch interactions, swipe gestures, device rotation, and platform-specific behavior that require mobile-native understanding.

Open-source multi-protocol API client

Firecamp is an open-source API DevTool supporting REST, GraphQL, WebSocket, and Socket.IO protocols as a lightweight alternative to Postman. It provides IntelliSense, team collaboration with shared workspaces, and seamless import from OpenAPI, Insomnia, AsyncAPI, and HAR formats. Each protocol gets a dedicated testing playground with response metrics including time, size, and status codes.

Open-source microVMs for secure serverless and AI agent sandboxing

Firecracker is an open-source virtual machine monitor that creates lightweight microVMs with sub-150ms cold starts, originally built by AWS for Lambda and Fargate. With 28,000+ GitHub stars, it provides kernel-level isolation for running untrusted code safely and powers the sandboxing infrastructure behind AI coding agents like Devin and E2B.

The friendly interactive shell

User-friendly interactive shell for Linux and macOS that works great out of the box with zero configuration needed. Features autosuggestions based on command history (accept with right arrow), syntax highlighting as you type, tab completions with inline descriptions, web-based configuration UI for themes and settings, and a scripting syntax that is simpler than bash/zsh. Not POSIX-compatible by design. Popular among developers who want a productive shell without customization effort.

Multilingual emotional text-to-speech with 80+ language support

Fish Speech is an open-source text-to-speech system supporting 80+ languages with emotional expression, zero-shot voice cloning, and real-time streaming. It generates natural speech with controllable emotions, speaking styles, and prosody. Features a web interface, API server, and integration with AI agent frameworks for voice-enabled applications. Over 29,000 GitHub stars.

Open-source feature flags and remote configuration

Flagsmith is an open-source feature flag and remote config platform with 15+ SDKs, a clean REST API, and simple Docker deployment. It supports boolean, multivariate, and string flags with segment-based targeting, A/B testing via flag variations, and environment-based workflows. Flagsmith provides a straightforward self-hosted alternative to LaunchDarkly with full API-first design under a BSD-3-Clause license.

Fast memory-efficient GPU attention kernels

FlashAttention is a fast and memory-efficient exact attention implementation that reduces GPU memory usage from quadratic to linear in sequence length. Created by Tri Dao, it achieves 3-4x speedups over baseline implementations through IO-aware tiling that minimizes HBM reads and writes. Versions include FlashAttention-2 with improved parallelism, FlashAttention-3 optimized for Hopper H100 GPUs, and FlashAttention-4 targeting Hopper and Blackwell architectures.

Usage metering and billing infrastructure for AI, API, and SaaS products

Flexprice is an AGPL-3.0 open-source platform for real-time usage metering, usage-based pricing, credits, entitlements, and billing workflows. It helps engineering and finance teams turn token, API, and feature events into billable usage across managed-cloud or self-hosted deployments. Use it when a product needs finance-grade chargeback and customer usage controls, not only LLM traces.

Free open-source local AWS emulator as a drop-in LocalStack replacement

Floci is a free open-source AWS emulator designed as a lightweight drop-in replacement for LocalStack Community Edition. It runs on port 4566 with the same endpoint conventions, supporting S3, SQS, DynamoDB, RDS, ElastiCache, API Gateway, Cognito, IAM, and twenty-plus other services. The Docker image is ninety megabytes versus LocalStack's one gigabyte and starts in twenty-four milliseconds.

Visual workflow builder by ByteDance

FlowGram is an open-source visual workflow and flowchart editor framework developed by ByteDance for building node-based workflow applications. It provides a React-based canvas with drag-and-drop node creation, configurable edge routing, zoom and pan controls, and a plugin architecture for extending functionality. FlowGram supports both fixed layout and free-form canvas modes, making it suitable for building AI agent pipelines, data processing flows, and automation builders.

GitOps toolkit for Kubernetes — continuous delivery the cloud-native way.

Flux is a CNCF graduated GitOps tool for keeping Kubernetes clusters in sync with configuration sources like Git repositories, Helm charts, and OCI artifacts. Lightweight, composable, and designed to work with existing tools. The primary alternative to ArgoCD in the GitOps space.

Blazing fast Solidity development toolkit

Foundry is a blazing-fast portable toolkit for Ethereum smart contract development written in Rust. It provides Forge for testing and deploying Solidity contracts with native Solidity tests that run orders of magnitude faster than JavaScript-based alternatives, Cast for interacting with EVM chains from the command line, Anvil as a local testnet node, and Chisel as a Solidity REPL. Foundry has become the standard toolchain for serious Solidity development.

Free and open-source Kubernetes IDE for managing clusters visually

Freelens is a free open-source Kubernetes IDE that provides a visual desktop interface for managing clusters, workloads, and configurations. Forked from the original Lens project after its licensing change, Freelens offers the same powerful cluster management experience with real-time monitoring, log viewing, and resource editing under the MIT license.

Beautiful docs for Next.js App Router

Fumadocs is a documentation framework built specifically for Next.js that provides a complete set of tools for creating high-performance documentation sites within the Next.js App Router. Offers tight integration with server components, middleware, and API routes, plus headless UI primitives, MDX processing, built-in search, and flexible theming — giving teams full control over their docs' look and feel.

Open-source voice cloning and text-to-speech with few-shot learning

GPT-SoVITS is an open-source voice cloning and text-to-speech system that generates natural-sounding speech from just a few seconds of reference audio. It combines GPT-style language modeling with SoVITS voice synthesis for zero-shot and few-shot voice cloning across multiple languages. Supports Chinese, English, Japanese, Korean, and Cantonese with over 56,000 GitHub stars.

Natural language scripting for LLM-system interaction

GPTScript is an Apache 2.0 licensed framework with 3,300+ GitHub stars that enables natural language scripting where LLMs interact with local systems, APIs, and tools through simple prompt definitions. It supports multiple model providers including OpenAI-compatible APIs and local models, providing a lightweight approach to building AI agents that can execute CLI commands, call APIs, and process files.

Open-source GPU control plane for scalable AI model serving

Open-source GPU cluster manager that configures vLLM, SGLang, TensorRT-LLM or custom engines, serves models through compatible APIs, and provisions SSH-accessible GPU instances across on-premises, Kubernetes and cloud environments.

Graph-relational database with EdgeQL query language, formerly EdgeDB

Gel (formerly EdgeDB) is a graph-relational database that combines the relational model with graph database traversal capabilities through its EdgeQL query language. Built on PostgreSQL, it eliminates the object-relational impedance mismatch with a type system that maps directly to application data models. Features built-in migrations, authentication, and an interactive web UI.

Meta-prompting and context engineering system for Claude Code agents

GSD is a meta-prompting, context engineering, and spec-driven development system designed for Claude Code and compatible AI coding agents. With over 46,000 GitHub stars, it implements a structured four-phase workflow of Discuss, Plan, Execute, and Verify to combat context rot in long AI coding sessions. The system uses multi-agent orchestration with persistent file-based memory.

MCP server for AI-powered reverse engineering

GhidraMCP is an MCP server that enables LLMs to autonomously perform reverse engineering tasks through NSA's Ghidra disassembly framework. It exposes binary analysis capabilities like decompilation, function listing, cross-references, and symbol analysis as MCP tools, letting AI assistants generate malware reports and analyze compiled binaries.

Bayesian git bisection for finding commits that caused flaky tests

Git Bayesect applies Bayesian inference to git bisection, solving the problem of finding commits that introduced non-deterministic bugs like flaky tests. Unlike standard git bisect which requires binary pass-fail results, Git Bayesect handles probabilistic outcomes where a test might pass sometimes and fail sometimes, using entropy minimization to efficiently narrow down the culprit commit.

Run AI coding agents in GitHub Actions from Markdown

Open-source GitHub CLI extension for defining repository automations in Markdown and running Copilot, Claude Code, Codex, Gemini or custom agents inside hardened GitHub Actions workflows.

Built-in CI/CD for GitLab

GitLab's built-in CI/CD pipeline system defined via .gitlab-ci.yml files in your repository. Features multi-stage pipelines, parallel jobs, matrix builds, environments with deployment tracking, merge train for serialized merges, auto DevOps for zero-config CI/CD, container registry, and security scanning (SAST/DAST). Supports self-hosted runners and Kubernetes executors. Tightly integrated with GitLab's merge requests and issue tracking. A leading alternative to GitHub Actions for GitLab users.

Instant MCP server for any GitHub repository

GitMCP is a free, open-source remote MCP server that transforms any GitHub repository or GitHub Pages site into an AI-accessible documentation hub. Just replace github.com with gitmcp.io in any repo URL to give AI assistants grounded context about that project — eliminating code hallucinations with zero configuration required.

Agent Development Kit by Google

Google's open-source framework for building AI agents with Gemini models. Supports multi-agent orchestration, tool use, and deployment to Vertex AI or Cloud Run. Provides a structured approach to agent development with built-in evaluation, testing, and monitoring capabilities, making it the official path for teams building agent systems within the Google Cloud ecosystem.

Run open-source LLMs on your phone, fully offline and private

Google AI Edge Gallery is an open-source mobile app that lets you download and run large language models like Gemma directly on Android and iOS devices with zero cloud dependency. Built on MediaPipe and LiteRT, it features AI chat with reasoning mode, multimodal image analysis, real-time audio transcription, and autonomous agent skills—all running entirely on-device for complete privacy. A reference implementation for developers building offline-first AI experiences.

MCP server for secure database tooling with AI agents

Google GenAI Toolbox is an open-source MCP server from Google that specializes in easy, fast, and secure database tools for AI agents. It provides structured database access through the Model Context Protocol, enabling agents to query, inspect schemas, and manage data across supported databases with built-in security controls.

First-party MCP server for querying and managing Grafana

Grafana's official Model Context Protocol server, letting AI assistants search dashboards, query datasources, and manage alerts/incidents on your Grafana instance through a standard MCP interface.

Turn code and docs into a queryable knowledge graph

Graphify is an open-source AI coding assistant skill that transforms folders of code, documentation, research papers, and images into queryable knowledge graphs. It works as a skill for Claude Code, Codex, OpenCode, and other AI coding assistants. Using tree-sitter AST parsing for 19 programming languages and Claude vision for documents and images, it builds NetworkX graphs with Leiden community detection, outputting interactive HTML visualizations and structured JSON for codebase exploration.

Build real-time temporal knowledge graphs for AI agents

Graphiti is an open-source Python framework by Zep for building temporally-aware knowledge graphs for AI agents. It continuously integrates conversations, business data, and external information into queryable graphs with bi-temporal tracking. The hybrid retrieval combines semantic search, BM25 keywords, and graph traversal for sub-300ms queries without LLM calls at retrieval time.

Data quality validation framework for Python

Great Expectations is an open-source Python framework for validating, documenting, and profiling data quality. Teams define expectations as expressive unit tests for their data using an intuitive API, then validate datasets against those rules in CI/CD pipelines or production workflows. It connects to pandas, Spark, and SQL sources, generates data documentation automatically, and integrates with orchestrators like Airflow and Prefect for continuous data quality monitoring.

Modular AI agent framework with off-prompt data

Griptape is an open-source Python framework for building AI agents and workflows with a focus on modularity and enterprise-grade off-prompt data handling. It separates predictable pipeline logic from unpredictable LLM interactions, providing structures for sequential and parallel task execution with built-in memory management and tool integration.

Production-grade Terraform modules and infrastructure library

Gruntwork provides a library of battle-tested, production-grade Terraform modules covering AWS, GCP, and Azure infrastructure patterns. Modules handle networking, compute, databases, security, monitoring, and compliance with best practices built in. Terragrunt, their open-source Terraform wrapper with 15k+ stars, adds DRY configuration, remote state management, and multi-account orchestration.

Constrained generation that guarantees valid LLM outputs every time

Guidance is Microsoft's structured generation library that enforces output constraints directly within LLM decoding. It supports JSON schemas, regex patterns, grammars, and interleaved generation-and-control flow to guarantee valid outputs from any compatible model. Works with local models via llama.cpp, Transformers, and remote APIs including OpenAI and Anthropic. Eliminates retry loops and post-processing for structured data extraction.