After this lesson, you will be able to: Understand what an AI agent is, the three tool tiers LastWrite teaches, and which tier matches your background and goals.
An 'AI agent' is a system that uses a language model in a loop with tools to take actions in the world, not just answer in chat. This intro lesson explains the core idea, walks through every tool we cover across no-code / low-code / code-first tiers, and helps you pick where to start.
This is a free introductory lesson. No purchase required.
A simple LLM call is one-shot: prompt in, text out. An agent runs in a loop, the model decides what to do next, calls a tool, observes the result, and loops until the task is done. Search the web, check a calendar, send an email, query a database, each is a tool the agent picks up when needed.
Tier 1. No-Code (n8n, Zapier, Make.com, Voiceflow): drag-and-drop, no programming. Best for non-developers automating real work fast. Tier 2. Low-Code (LangFlow, Flowise, Dify, Relevance AI): visual canvas with the power of LangChain underneath. A bit of Python helps but isn't required. Tier 3. Code-First (LangChain, LlamaIndex, CrewAI, raw SDKs, MCP): full Python code, total control, production-grade. The pro tier.
1. Comfortable with Python and want full control? → Code-First.
2. Some technical background, want visual tools but real power? → Low-Code.
3. Want to build automations fast without learning syntax? → No-Code.
4. Unsure? Start No-Code (1 lesson) to feel the loop, then jump to your real tier.
Pick the answer that captures the agent's defining trait.