9Router
Focus: llm gateway, codex and free ai. Shares claude code and cursor with OpenCastle. Freemium (OpenCastle: Free). Adds Web. Rated 4.5 (OpenCastle: 4.4).
AI ToolFree planWeb, Cross-Platform
4.5Visit
AI Tool
OpenCastle
Write your AI assistant config once and use it in every assistant.
Rating
4.4 / 5
Pricing
Free
Difficulty
Intermediate
Works on
Cross-Platform
Built with love by Shushant Lakhyani. Building bestproductivityresources.com
What is OpenCastle?
OpenCastle compiles one source of AI assistant configuration into the formats used by GitHub Copilot, Cursor, Claude Code, OpenCode, Windsurf, Codex and Antigravity, and tells you when they fall out of sync. Run it with npx to read your repository and set things up.
Third-party open-source projects. We are not affiliated with their authors; repositories are provided as-is by their maintainers. Review each project's license, code and security before installing. See our Disclaimer.
Pros: what OpenCastle does well
- One source for many assistants
- Warns when configs drift apart
- Quick start with npx
Cons: where it falls short
- Aimed at developers
- Another layer to learn
OpenCastle alternatives
Not sold on OpenCastle? These do a similar job, and each card says what it has in common.
dispatchseo
Focus: seo, ai agents and marketing. Shares claude code and cursor with OpenCastle. Adds Web. Same 4.4 rating.
AI ToolFreeWeb, Cross-Platform
4.4Visit
Agent Skills Workflow Template
Focus: agent skills, agents.md and codex. Shares claude code and cursor with OpenCastle. A website, not an AI tool. Adds Web. Rated 4.7 (OpenCastle: 4.4).
WebsiteFreeWeb, Cross-Platform
4.7Visit
Agentfiles
Focus: obsidian, obsidian plugin and ai agents. Shares claude code and cursor with OpenCastle. A website, not an AI tool. Adds Web, macOS and Windows. Rated 4.7 (OpenCastle: 4.4).
WebsiteFreeWeb, macOS
4.7Visit
ASO Skills
Focus: aso, app store optimization and app marketing. Shares claude code and cursor with OpenCastle. A website, not an AI tool. Adds Web. Rated 4.7 (OpenCastle: 4.4).
WebsiteFreeWeb, Cross-Platform
4.7Visit
FFmpeg Skill
Focus: ffmpeg, video editing and ai agent skill. Shares claude code and cursor with OpenCastle. An automation tool, not an AI tool. Adds macOS, Windows and Linux. Rated 4.7 (OpenCastle: 4.4).
Automation ToolFreemacOS, Windows
4.7Visit
Free alternatives to OpenCastle
Want to spend nothing? These free picks cover similar ground.
agtx
Focus: coding agents, codex and rust. Shares claude code and cursor with OpenCastle. A desktop app, not an AI tool. Adds macOS, Linux and Windows. Rated 4.5 (OpenCastle: 4.4).
Desktop AppFreemacOS, Linux
4.5Visit
video-shotcraft
Focus: ai video, remotion and product video. Shares claude code with OpenCastle. Rated 4.7 (OpenCastle: 4.4).
AI ToolFreeCross-Platform
4.7Visit
Claude Skills Collection
Focus: claude, skills and ai agents. Shares cursor with OpenCastle. Adds macOS, Windows and Linux. Rated 4.6 (OpenCastle: 4.4).
AI ToolFreemacOS, Windows
4.6Visit
Figma to Code Skill
Focus: figma, figma to code and design handoff. Shares claude code with OpenCastle. Adds Web. Rated 4.6 (OpenCastle: 4.4).
AI ToolFreeWeb
4.6Visit
OpenHarness
Focus: agent harness, coding agents and codex. Shares claude code with OpenCastle. Adds Linux. Rated 4.6 (OpenCastle: 4.4).
AI ToolFreeCross-Platform, Linux
4.6Visit
Builder.io Skills
Focus: ai agents, skills and builder.io. Shares claude code with OpenCastle. Rated 4.5 (OpenCastle: 4.4).
AI ToolFreeCross-Platform
4.5Visit
Are you the maker of OpenCastle?Get a free Featured badge for your site, a share image and ready-to-paste posts. No sign-up.
New · updated daily
What people are actually doing with AI
Real use cases shared on Reddit, Hacker News, X, GitHub and blogs, summarised in plain words with a link to every original post.
Free Notion database
1,100+ ways people are making money online
Real online businesses, creators and projects, broken down by how they make money: apps, online stores, AI tools and more. Free on Gumroad.
Get the free databaseFree Notion database
399+ ways to make money online
Hundreds of online income methods in one place, so you can compare options and pick one to try. Free on Gumroad.
Get the free listFor research and ideas only. Results vary and nothing here is a promise of income. See our Disclaimer.
Weekly newsletter
Everything new, every Monday.
One short email every Monday with everything shipped that week: new free tools and websites, new guides, new free browser tools and what's new in my free Gumroad libraries, plus how the site is growing. Free, and you can unsubscribe anytime.
Join the newsletterYou sign up on Gumroad, which stores your email to send the newsletter. See our Privacy Policy.