flompt is an open-source visual prompt builder that helps you engineer and optimize prompts for LLMs by decomposing any raw prompt into typed, editable blocks (role, objective, constraints, examples, output format, chain-of-thought, document, language, etc.) and recompiling them into Claude‑optimized XML; it runs as a web app and browser extension (injectable into ChatGPT, Claude & Gemini) and exposes an MCP server so agents can call decompose_prompt/compile_prompt programmatically. flompt applies Anthropic’s prompting best practices, enforces optimal block order and XML grounding, and makes few‑shot examples, format controls, and reasoning explicit so you get more consistent, reliable, and token‑efficient AI outputs—useful for prompt engineers, AI developers, content creators, and anyone who needs repeatable, high‑quality LLM behavior.