Build AI Agents that
matter.

A free, open source visual builder for AI Agent Skills, Prompts, and MCP Configurations. Pick an archetype, customize components, copy the code. Done in minutes.

Works with

VS CodeGitHub CopilotCursorClaude CodeWindsurfOpenClawClaude DesktopAny MCP Client

Three steps, one file

From blank page to production-ready config

Pick an archetype

Agent Skill, MCP Config, System Prompt, OpenClaw Skill, or Copilot Instructions — choose the structure that fits your use case.

Choose a template

Start from a pre-made template, use the archetype defaults, or begin from scratch. Then add components to customize.

Edit, copy & ship

Customize components in the visual editor, preview the output live, then copy or download your file. Done.

New

Now with OpenClaw support

Build SKILL.md files for OpenClaw — the open source personal AI assistant with 200k+ stars. Create skills that work across WhatsApp, Telegram, Slack, Discord, and more.

5,700+

Community Skills

Published on ClawHub, the official OpenClaw skills registry.

15+ Channels

Multi-Platform

WhatsApp, Telegram, Slack, Discord, iMessage, Teams, and more.

Same Format

AgentSkills Compatible

SKILL.md with YAML frontmatter — works with VS Code Agent Skills too.

50+ Building Blocks

YAML frontmatter, tool definitions with JSON Schema, MCP server entries, environment variables, few-shot examples, and more.

Real Output Formats

Generates valid .agent.md, SKILL.md, .mdc, CLAUDE.md, .windsurfrules, and OpenClaw skill files — not pseudocode.

Instant Preview

See rendered markdown and raw source side-by-side as you build. Every edit updates live.

Open Source, No Lock-in

MIT licensed. No account, no telemetry, no server. Everything runs in your browser.

See it in action

Pick an archetype, customize components, preview your file in real-time

frontmatter.cc/builder/agent-skill
---
name: code-reviewer
description: Reviews PRs
version: 1.0.0
---
## Role: Code Reviewer
You are an expert code reviewer.
- Check for security issues
- Suggest performance gains
Tap to explore • VS Code Agent Skill

Frequently Asked Questions

Everything you need to know about building AI Agent files

An AI Agent Skill is a markdown file with YAML frontmatter that defines custom instructions, tools, and behaviors for AI assistants like GitHub Copilot. It allows you to extend the AI's capabilities with your own domain knowledge.

Model Context Protocol (MCP) allows AI models to securely connect to local or remote data sources. An MCP configuration is a JSON block that tells your AI client (like Claude Desktop or VS Code) how to connect to these servers.

Yes, completely free and open source under the MIT license. No account required, no hidden fees, no premium features locked behind a paywall.

Click Copy or Download in the builder, then place the file in the right location for your editor: .github/agents/ for VS Code, .cursor/rules/ for Cursor, CLAUDE.md for Claude Code, .windsurfrules for Windsurf, or skills/ for OpenClaw.

Archetypes define the structure and output format for a specific editor or use case — VS Code Agent Skills, Cursor Rules, Claude Code, OpenClaw Skills, MCP Server Configs, System Prompts, and more. Pick one, then choose from matching templates or start from scratch.

Absolutely. Every component is editable—change your agent's name, define custom JSON schemas for tools, add few-shot examples, or configure environment variables.

Your next agent starts here

No account needed. No data leaves your browser.

Free and open source — forever.

Open the Builder