I built a free AI agent builder with 4 research-backed strategies (runs in your browser, BYOK)

I wanted a way to run an AI agent loop without installing anything, managing dependencies, or paying for a SaaS subscription. So I built one that runs entirely in your browser. AI Agent Builder — Free, BYOK, No Backend What it does Paste your OpenAI or Gemini API key, type a goal, and watch an autonomous agent work through it step by step. The agent plans, executes, and verifies — all client-side. Your key goes directly to the API provider, never to my servers. There is no backend. Four strategies based on real research The tool implements four proven agentic loop patterns from Anthropic, OpenAI, and Google DeepMind research: Plan & Execute — breaks the goal into steps, executes each one, then verifies. Best for structured tasks like research or content creation. ReAct (Reason + Act) — the agent thinks, acts, observes, and adapts on every iteration. From the original Princeton/Google Brain paper. Best for open-ended exploration where you don't know the steps upfront. Reflection Loop —