13 Developer Tools tools (11 free)
13 Developer Tools resources, picked out of 2 saved Instagram reels and 11 liked tweets, from creators like @leodev, @vercel, @benjitaylor. 11 of them are free, freemium or open source.
react-best-practices is an open-source knowledge base and agent skill developed by Vercel to optimize React and Next.js applications. It organizes over 40 performance rules ranked by impact—from eliminating request waterfalls to cutting bundle sizes—into formats consumable by developers and AI coding agents. The rules compile into an AGENTS.md document to guide automated refactoring tools like Cursor, Claude Code, and Codex.
Agentation is a visual feedback system and MCP server that bridges browser toolbars directly to AI coding agents like Claude Code. Its Critique Mode autonomously inspects web pages and leaves targeted UI/UX annotations, while Self-Driving Mode edits the underlying code to resolve those issues automatically.
claude-office-skills provides workflows, scripts, and prompt instructions for Claude Code to programmatically create and edit PPTX, DOCX, XLSX, and PDF files. It replicates the document manipulation skills used by Claude's desktop interface into a terminal-friendly repository for automated pipelines. Users can generate slide decks from HTML, track changes in Word documents, construct formula-accurate spreadsheets, and fill PDF forms.
Domain SDK provides a unified TypeScript client to programmatically add, verify, monitor, and remove custom domains on hosting platforms like Vercel, Cloudflare, and Netlify. It normalizes DNS record generation, verification states, and TLS certificate tracking across different backends. This saves multi-tenant SaaS developers from writing bespoke domain-handling infrastructure.
ECC (formerly Everything Claude Code) is an open-source repository of modular configurations, skills, instincts, hooks, and security guardrails for AI coding assistants. It provides battle-tested harness setups designed to optimize performance across Claude Code, Codex, Cursor, Gemini, and related agent tools.
A curated collection of eight developer and designer resources highlighting micro-interactions, AI coding workspaces, and web builders. It points directly to specialized component libraries like Amicro and MicroKit alongside workflow tools like Superset and Blink.
Framecap is a CLI-based screen recording utility built for macOS that captures screen video, webcams, and audio inputs using straightforward terminal flags. It allows users to record multiple synchronized tracks directly to an output folder without navigating a complex desktop interface.
Hemingway AI is an open-source tool that turns your localhost marketing site into an interactive copywriting canvas. Clicking any text element generates AI-written alternatives calibrated to the page's structure and voice. Selecting an alternative immediately updates the live page and writes the edit back into your local source files.
Natural Language Postgres is an open-source demo app built with the Vercel AI SDK and Next.js. It converts plain English questions into SQL, runs them against a PostgreSQL database, and visualizes the results as tables or charts. It also generates clause-by-clause explanations of the generated SQL queries.
Repomix is a CLI tool and web app that condenses your entire repository into one structured file formatted for large language models. It handles file trees, token counts, and git ignores so you can feed full context to models like Claude, ChatGPT, or Gemini without manual copying. It also integrates Secretlint to avoid leaking credentials and offers Tree-sitter code compression to save context tokens.
Social SDK is an open-source, typed TypeScript library that connects your app to platforms like X, Threads, Bluesky, YouTube, TikTok, LinkedIn, and Instagram. It handles publishing, post analytics, comments, and direct responses with granular, platform-specific status reporting rather than rolled-up booleans. It also ships with offline mock backends for CI testing and integrations with managed token services.
visual-json is a developer tool and UI component library created by Vercel Labs for viewing and editing JSON and YAML data through an interactive tree. It replaces raw text manipulation with inline row editing, breadcrumb navigation for nested paths, and drag-and-drop reordering. The project is modular, offering headless models, web framework bindings (React, Svelte, Vue), and a dedicated VS Code extension.
Visual Studio Code includes a built-in port forwarding system that creates dev tunnels for localhost services. It lets you test locally hosted web apps on physical mobile devices over HTTPS without installing third-party tools like ngrok.