In this video, I break down the most “happening” launch from OpenAI Dev Day 2025: the Agent Builder inside Agent Kit. I walk you through what OpenAI is actually shipping—an end-to-end set of building blocks for building, deploying, and optimizing agents—because until now, agent development has been a messy mix of fragmented tools, custom connectors, manual pipelines, prompt tuning, and weeks of UI work before you can even launch. Then I go hands-on with the Agent Builder workflow canvas: start node, connectors like file search, guardrails, branching logic, LLM/RAG, and external MCP tools. I recreate the live demo pattern—build a classifier agent that outputs JSON, route via an if/else node into a flight agent (with web search) or an itinerary agent (pure model output), preview-run it, and even add a widget for richer flight results. The killer feature is one-click deploy: OpenAI hosts and runs the workflow, and you can invoke it via the Agent SDK or just a workflow ID. Finally, I give my production take: this is amazing for quick wins and getting started with minimal coding, but “production-grade” needs more—guardrails, observability, performance, edge-case handling. I also compare the philosophy vs LangChain, including why LangChain has been cautious about visual builders and where code/graph-based systems still win at scale.