Best Free AI Developer Tools tools

A transparent proxy that shows every real tool call between your AI client and MCP servers, live in your terminal.

Mirrors turns your production traces into an isolated copy of your agent's environment so you can test changes safely.

An open-source CLI for fast local search across your past coding agent sessions.

A secure file system and code execution sandbox for AI agents with built-in job queues, Docker isolation, and execution history.

Build production-ready full-stack apps from a prompt with built-in auth, database, and deployment—now with native mobile support.

Behavioral infrastructure for humanlike AI agents, providing APIs and models for social intelligence in group interactions.

A feature-rich Pomodoro timer that lives inside the Claude Code terminal, keeping focus without context switching.

A lightweight CLI tool for detecting non-exact code duplication using embedding models.

A macOS app that keeps AI agent essentials like Claude and Codex sessions, token usage, and permissions visible in your Mac notch.

A unified Python library that combines MCP servers, agent skills, custom functions, and HTTP endpoints into a single tool set for building AI agents with any LLM.

A transparent proxy that shows every real tool call between your AI client and MCP servers, live in your terminal.

Mirrors turns your production traces into an isolated copy of your agent's environment so you can test changes safely.

An open-source CLI for fast local search across your past coding agent sessions.

A secure file system and code execution sandbox for AI agents with built-in job queues, Docker isolation, and execution history.

Build production-ready full-stack apps from a prompt with built-in auth, database, and deployment—now with native mobile support.

Behavioral infrastructure for humanlike AI agents, providing APIs and models for social intelligence in group interactions.

A feature-rich Pomodoro timer that lives inside the Claude Code terminal, keeping focus without context switching.

A lightweight CLI tool for detecting non-exact code duplication using embedding models.

A macOS app that keeps AI agent essentials like Claude and Codex sessions, token usage, and permissions visible in your Mac notch.

A unified Python library that combines MCP servers, agent skills, custom functions, and HTTP endpoints into a single tool set for building AI agents with any LLM.

Local-first memory for AI coding agents. Automatically stores and recalls project context via MCP, offline, with ~35ms recall.

A self-hosted, browser-based AI CSV analyzer that uses multiple AI providers to analyze and visualize CSV and Excel data.

AXIOM is a bootable Rust kernel that optimizes transformer inference by replacing generic OS abstractions with inference-specific primitives.

A CLI tool that checks package versions for known vulnerabilities across npm, PyPI, and many other ecosystems, designed for AI agents to avoid using outdated packages.

An open-source ML pipeline that diagnoses car faults from audio by cleaning sound, embedding with CLAP, and training calibrated linear classifiers.

Kage is a git-native verification layer for coding agent memory that checks every claim against your code to prevent hallucinations and stale facts.

An open-source Agent UI library in VanillaJS for building agentic front-end experiences with WebMCP, SSE streaming, and customizable theming.

CoWork transforms existing test cases into automated mobile tests using AI planning and real-device execution.

Turn any HTML or Markdown doc from AI tools into a living, shareable link with real-time comments and version control.

Real-time event monitoring infrastructure for AI agents that delivers low-latency data streams and webhook notifications to trigger automated workflows.

Fleet is a local-first web console for creating, configuring, monitoring, and operating Dockerized Hermes AI agents across trusted machines.

Vibe-zsh is an AI-powered Oh-My-Zsh plugin that transforms natural language into shell commands using any OpenAI-compatible API.

Keeps your Mac awake only while AI coding agents are actively working, and lets it sleep when they finish.

An open protocol for capability-aware AI routing, plus a reference router that routes between local and cloud AI models based on task, cost, and latency.

A skill for coding agents that delegates coding, planning, review, and orchestration tasks to the zerostack CLI agent.

Open-source reliability testing harness for AI agent skills, computing pass@k scores across Claude Code, Codex, and Pi backends.

A secure, portable Bash-first CLI wrapper for Groq's OpenAI-compatible API to interact with large language models from the terminal.

Automated end-to-end few-shot text classification pipeline supporting 50+ languages, built on SetFit and SBERT embeddings.

A reference implementation using Linux Pressure Stall Information to trim LLM KV cache under memory pressure.

A drop-in proxy that routes every prompt to the best AI model in <50ms, cutting costs 40-70% with just an endpoint change.

Polygraph indexes every repo you have access to and builds a graph of how they relate, enabling AI agents to plan cross-repo work without being told where to look.

AI-powered security validation that automatically finds vulnerabilities, generates pull requests with patches, verifies fixes, and provides compliance evidence.

A local-first MCP gateway that reduces token usage by ~90% by exposing 3 meta-tools instead of hundreds, working across all major AI clients.

An open-source CLI toolkit for simulating AI training math, estimating model size, memory, training time, and token budget.

Lightweight, themeable AI chat widget for websites built with vanilla JS, supporting streaming, voice, tool calls, and a plugin system.

Beautiful, AI-native markdown editor and LLM Wiki for creating and managing knowledge bases with AI assistance.

A transpiler from stateful imperative workflows to declarative DSPy programs for reliable, optimizable LLM steps with zero boilerplate.

Bluerails provides AI agent payment infrastructure and commerce tools, enabling businesses to be discovered, interacted with, and paid by AI agents.

Diffen.ai is an AI-powered code review tool that reviews Pull Requests, finds issues, and automatically fixes them, pushing changes to a new branch.

Open source authorization engine for AI agents that provides confidence-aware gating, human-in-the-loop review, policy-as-code, and full audit trail.

peerd is the first AI agent harness native to the browser, allowing AI agents to drive tabs, run sandboxed compute, and share peer-to-peer with no backend.

A CLI tool that converts web pages into compact text accessibility trees for LLMs to automate browser interactions efficiently.

HALO is a methodology and toolkit for recursively self-improving AI agent harnesses using RLMs and production traces.

Graphsignal is a production-scale inference profiling platform that helps engineers optimize AI performance across models, engines, GPUs, and other accelerators.

A read-only Markdown and HTML reader for macOS, purpose-built for reviewing AI-generated documents in development workflows.

Alma is a local-first MCP server that gives AI agents a private, consent-based memory of your personal facts and preferences.

Oak is an agent-native version control system with a lazy working tree, JSON-first CLI, and branch management designed for AI coding agents.

Caplets gives AI agents focused capabilities by turning sprawling MCP servers into progressive disclosure cards, reducing context usage and keeping schemas out of prompts until needed.

Skybridge is a full-stack TypeScript framework for building type-safe MCP apps and servers with React-powered UI.

Per-block model routing CLI that sends tagged prompt sections to different LLMs for optimized AI coding workflows.

A transparent proxy that shows every real tool call between your AI client and MCP servers, live in your terminal.

Mirrors turns your production traces into an isolated copy of your agent's environment so you can test changes safely.

An open-source CLI for fast local search across your past coding agent sessions.