# Free Tier

AI test writing with self-healing and visual editor

DogQ is a testing tool that writes, heals, and suggests tests automatically through a visual interface for managing the entire testing lifecycle. It provides a low-code alternative for teams without dedicated SDETs (Software Development Engineers in Test), automating test creation from user interactions and maintaining test health as the application evolves with AI-driven self-healing.

Universal secrets management platform

Doppler is a secrets management platform that centralizes environment variables and configuration across applications, CI/CD pipelines, and cloud infrastructure. Features automatic secret syncing to 150+ integrations including AWS, GCP, Azure, Vercel, Netlify, Docker, and Kubernetes. Provides versioned secret history, access controls with audit logs, secret rotation, environment-specific configs, and a CLI for local development. Replaces scattered .env files with a single source of truth.

Local open-source AI app builder running entirely on your machine

Dyad is a local-first, open-source AI app builder with 20,000+ GitHub stars that provides a Lovable and Bolt.new alternative running entirely on your machine. It supports React and Next.js frameworks, integrates with Ollama for fully offline AI generation, and works cross-platform on macOS, Windows, and Linux with both cloud and local LLM providers.

Prompt engineering framework treating prompts as versioned Python functions

Ell is a prompt engineering library that treats LLM prompts as versioned, testable Python functions rather than opaque strings. Built by ex-OpenAI researcher William Guss, it provides automatic prompt versioning with content-addressable hashing, a local TensorBoard-like studio for visualizing prompt evolution, and structured output support via Pydantic. 5,800+ GitHub stars, MIT licensed. Designed for teams who want to version-control and systematically improve their prompts over time.

Extensible self-documenting editor with Elisp environment

GNU Emacs is the extensible, self-documenting text editor that has served as a complete computing environment for developers since 1985. More than a text editor, Emacs is a Lisp-based platform that can be extended to handle virtually any text-related task — from writing code to managing email, shells, git, and org-mode planning. Highly keyboard-driven, deeply customizable, and completely free/GPL.

AI coding agent for embedded systems and firmware engineering

Embedder is a specialized AI coding agent for firmware and embedded systems development. It supports 400+ MCU variants including STM32 and ESP32, parses hardware datasheets to understand register maps and pin configurations, and verifies generated code by interacting with physical boards via serial console. YC S25 participant currently in beta.

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.

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.

No-code knowledge base platform with visual AI workflow and built-in RAG

FastGPT is an open-source no-code AI knowledge base platform with 27,000+ GitHub stars and 500,000+ users worldwide. It combines visual workflow orchestration, built-in RAG pipelines, QA-pair extraction, and API-aligned completions into a single deployable stack that runs on just 2GB RAM via Docker one-liner deployment.

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 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.

Run your app close to users

Global application hosting platform that runs full-stack apps, databases, and services close to users in 30+ regions using lightweight Firecracker micro-VMs. Deploy Docker containers or use built-in builders for Rails, Laravel, Django, Node.js, and Go. Features persistent volumes, private networking, auto-scaling, PostgreSQL/Redis managed databases, and a powerful CLI. Ideal for latency-sensitive apps needing multi-region presence. Generous free allowance with pay-as-you-go pricing.

Builder.io visual canvas with Figma-to-code and code-to-Figma sync

Fusion by Builder.io is a visual development canvas that provides bidirectional sync between Figma designs and production code. Designers edit in Figma while developers work in code, and changes propagate in both directions. Supports React, Vue, Svelte, Angular, and Qwik output with a visual editor for non-developers to make content and layout changes without touching code.

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.

Knowledge management for teams

Modern documentation platform that combines a WYSIWYG editor with Git-backed version control for technical documentation, API references, and knowledge bases. Features real-time collaboration, OpenAPI/Swagger integration for auto-generated API docs, custom domains, visitor authentication, and AI-powered search. Syncs bidirectionally with GitHub/GitLab repositories. Includes analytics for tracking documentation usage. Used by Ethereum, Linux Foundation, and thousands of developer teams.

Built-in project planning for GitHub

GitHub's built-in project management tool that organizes issues, pull requests, and draft items into customizable boards, tables, and roadmap views directly within your repositories. Features custom fields, automated workflows for moving items based on PR/issue status, grouping, filtering, milestones, and iteration planning. Integrated with GitHub Issues and PRs for seamless developer workflows. Free for all GitHub users. A lightweight alternative to Jira for GitHub-centric teams.

Visual Git client with built-in collaboration

GitKraken is a cross-platform visual Git client providing an intuitive graph visualization of repository history, branches, and merges. Features include drag-and-drop branch management, interactive rebase, merge conflict editor, built-in code editor, GitFlow support, and integrations with GitHub, GitLab, Bitbucket, and Azure DevOps. Includes GitLens for VS Code providing inline blame annotations, code authorship, and commit history. Free for public repos, paid for private repositories.

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.

Most popular VS Code Git extension with 30M+ installs

GitLens is the most-installed Git extension for VS Code with over 30 million installs. It supercharges Git inside the editor with inline blame annotations, rich commit history visualization, file and line history, AI-powered commit summaries, and interactive rebase tools. Pro features include GitKraken-powered team analytics and visual diff tools. Maintained by GitKraken.

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.

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.

Synthetic data generation platform for privacy and ML

Gretel is a synthetic data platform that generates realistic, privacy-preserving datasets for ML training, testing, and data sharing. It supports tabular, text, and time-series data with configurable privacy guarantees including differential privacy. Features include data augmentation for imbalanced datasets, PII detection and anonymization, and API/SDK access for pipeline integration with BigQuery, Snowflake, and Databricks.

Human-friendly HTTP client

User-friendly CLI HTTP client for testing and debugging APIs with intuitive syntax, colorized output, and JSON highlighting. Simpler than curl with sensible defaults — auto JSON formatting, persistent sessions, and auth helpers. Also available as HTTPie Desktop (GUI) and HTTPie for Web (browser-based). Supports HTTPS, proxies, file uploads, and plugins. 34K+ GitHub stars. The developer-friendly curl alternative for API work.

All-in-one browser DevTools extension for web developers

Hoverify is a browser extension that consolidates essential web development tools into a single overlay interface. It provides element inspection with CSS details, responsive design testing, accessibility checking, color picking, screenshot capture, and asset downloading. Activated by hovering over any webpage element, it provides instant development context without opening browser DevTools.

CLI tool for running and testing HTTP requests from plain text files

Hurl is a command-line tool that runs HTTP requests defined in simple plain text files with built-in assertions for testing. It supports GET, POST, PUT, GraphQL, multipart, cookies, authentication, and response validation with JSONPath, XPath, and regex. Chain multiple requests with variable capture between steps. 17,000+ GitHub stars, Apache 2.0 license, written in Rust for speed. Ideal for API testing in CI/CD pipelines as a lightweight alternative to Postman collections.

Local-first AI notepad for meetings and voice notes

Hyprnote is a local-first AI notepad designed for capturing and processing meeting notes and voice recordings. It runs entirely on-device for privacy, transcribes audio using local models, and generates structured summaries, action items, and follow-ups. Built with Rust and Tauri for native desktop performance. Over 8,000 GitHub stars with strong privacy-focused community adoption.

Open-source secrets management platform

Infisical is an open-source secrets management platform with 16K+ GitHub stars for syncing environment variables and secrets across teams, CI/CD pipelines, and infrastructure. Features end-to-end encryption, automatic secret rotation, dynamic secrets, access controls with audit logs, and native integrations with AWS, GCP, Azure, Kubernetes, Docker, GitHub Actions, and Vercel. Replaces scattered .env files with a centralized, encrypted secrets store accessible via dashboard, CLI, SDK, or API.

Durable workflow orchestration for serverless and edge

Inngest is a workflow orchestration platform that replaces queues, state management, and scheduling with durable step functions. Write functions in TypeScript, Python, or Go that survive failures, sleep for days between steps, and retry only failed steps. SDKs integrate natively with Next.js, Vercel, and serverless platforms. Free tier includes 50,000 runs/month. Used by Resend, Mintlify, and Ocoya for background jobs, AI orchestration, and event-driven workflows.

Open-source API client

Open-source API client by Kong for designing, debugging, and testing REST, GraphQL, gRPC, and WebSocket APIs. Features a clean interface with environment variables, authentication helpers, code generation, cookie management, and response timeline. Supports OpenAPI and Swagger specs for design-first workflows. Git Sync for version-controlled API collections. Available on macOS, Windows, and Linux. A popular alternative to Postman with stronger focus on privacy and local-first usage.

Pretty-print JSON in the browser

Open-source browser extension that automatically pretty-prints JSON responses in the browser tab. Supports collapsible nodes, syntax highlighting, and raw/formatted toggle. Essential developer tool for anyone who works with APIs regularly, turning unreadable JSON blobs into navigable, color-coded trees that make debugging API responses significantly faster and less error-prone.

BEAM/Elixir-native framework for durable multi-agent systems

Jido is an Elixir-native AI agent framework that leverages the BEAM virtual machine's concurrency and fault-tolerance for building durable, distributed multi-agent systems. It provides primitives for agent lifecycle management, skill composition, and message-based coordination. Designed for teams running Elixir in production who need agent capabilities. Apache-2.0 with 1,600+ GitHub stars.

Open-source AI second brain with deep research and RAG

Khoj is an open-source personal AI app that serves as a self-hostable second brain. It connects to your documents — PDFs, Markdown, Notion, Word — and uses RAG to answer questions grounded in your knowledge base. Supports any local or cloud LLM including Llama, Claude, GPT, and Gemini. Features custom agents, scheduled automations, deep research mode, semantic search, and Obsidian, Emacs, and WhatsApp integrations. Over 33,000 GitHub stars, YC-backed.

Auth platform combining authentication, feature flags, and billing

Kinde is a developer-focused authentication platform that bundles user management, feature flags, and billing management into a single service. It provides social login, passwordless auth, MFA, RBAC, and organization management out of the box. SDKs available for Next.js, React, Node, Python, and other frameworks. Free tier supports up to 10,500 monthly active users.

CNCF Sandbox chaos engineering framework for Kubernetes resilience

Krkn is a CNCF Sandbox chaos engineering tool that tests Kubernetes cluster resilience by injecting controlled failures. It simulates pod kills, node failures, network partitions, CPU/memory pressure, and zone outages. Krkn-AI adds AI-powered scenario generation that suggests chaos experiments based on cluster topology. Supports CI/CD integration for automated resilience testing in deployment pipelines.

Open-source multi-type data labeling platform

Label Studio is an open-source data labeling tool by HumanSignal supporting images, text, audio, video, and time series. It offers ML-assisted pre-labeling, customizable XML-based annotation interfaces, multi-user review workflows, and REST API access. Used for computer vision, NLP, speech, and LLM fine-tuning including RLHF annotation pipelines.

Twelve-lesson curriculum for building AI coding agents from scratch

Learn Claude Code is a comprehensive educational framework with 12 structured lessons teaching AI coding agent construction from first principles. With over 46,000 GitHub stars and 7,000 forks, it provides complete runnable Python implementations progressing from a 50-line bash agent to a 550-line skills agent with modular extensibility and subagent orchestration.

Memory-first coding agent that learns over time

Letta Code is a memory-first CLI coding agent that persists across sessions and improves over time. Unlike stateless tools like Claude Code or Codex, it works with long-lived agents remembering your codebase, preferences, and past interactions. Model-agnostic supporting Claude, GPT, Gemini, and more. Features git-backed context repositories, skill learning from experience, sleep-time reflection, and subagent orchestration. #1 model-agnostic OSS harness on Terminal-Bench.

Auto-generates interactive ER diagrams from database schemas

Liam ERD automatically generates beautiful, interactive entity-relationship diagrams from existing database schemas. It supports Rails schema.rb, PostgreSQL, Prisma, and raw SQL — with zero configuration required. A web version handles public repos instantly, while the CLI processes private repositories with CI/CD integration for keeping documentation in sync.

AI localization engine for software and docs

Lingo.dev is a Y Combinator F24-backed AI localization engine that automates translation of software interfaces and technical documentation into multiple languages while maintaining technical context. It preserves code variables, formatting tokens, and technical terminology that generic translation tools mangle, solving the global reach problem for developer-facing products and documentation.

AI-powered design to frontend code

Locofy is a design-to-code platform that converts Figma and Adobe XD designs into production-ready frontend code with high fidelity. Uses AI to automatically generate clean, responsive HTML/CSS/React/Next.js/React Native code from design files — eliminating labor-intensive manual translation. Includes Locofy Lightning for one-click conversion and Builder mode for custom components.

Async video messaging for teams

Asynchronous video messaging platform that lets users record their screen, camera, or both and instantly share via a link — replacing many live meetings and lengthy written explanations. Loom includes auto-transcription, AI summaries, timestamped comments, viewer analytics, password protection, in-app trim/stitch editing, and embeds in Notion, Confluence, and Slack.

Community self-hosted MCP server for Jira and Confluence (Python)

MCP Atlassian is a community-built, self-hosted Python MCP server (sooperset/mcp-atlassian) that connects AI coding agents to Jira and Confluence using API tokens or personal access tokens. It runs on your own infrastructure and supports both Cloud and Server/Data Center deployments — a flexible alternative to Atlassian's official remote MCP server when you need on-prem control, custom auth, or self-managed configuration.

Official debugger for MCP server development

MCP Inspector is the official interactive developer tool from the Model Context Protocol team for testing, debugging, and validating MCP servers. It provides a visual interface to inspect available tools, test transport configurations, export configs for different clients, and verify protocol compliance during MCP server development.

Official TypeScript SDK for building MCP servers

The official TypeScript SDK for the Model Context Protocol, providing everything needed to build MCP servers and clients. Supports stdio, SSE, and Streamable HTTP transports with built-in auth helpers. Works across Node.js, Bun, and Deno runtimes for maximum deployment flexibility.

Security scanner for MCP servers against tool poisoning attacks

MCP-Scan is a security tool that scans MCP servers for vulnerabilities including tool poisoning, prompt injection, cross-origin escalation, and rug pull attacks. Acquired by Snyk in 2026, it is the first dedicated security scanner for the MCP ecosystem. It analyzes tool descriptions, permissions, and behavior patterns to detect malicious or compromised MCP servers before they can exploit AI agents.

Design-system-aware AI prototyping for code-ready product interfaces

Magic Patterns turns product ideas, prompts, screenshots, and existing UI into editable, code-ready interfaces. Its design-system-aware editor supports collaborative iteration, two-way GitHub sync, and an MCP workflow for moving designs between the canvas and coding agents—positioning it between prompt-to-app builders and design-handoff tools rather than as a single-screen generator.