A Building Agentic AI

Blog / Beginner

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Beginner posts

Posts for software people new to AI. What agents are, the agent loop, prompting, RAG, tool calling, and the building blocks of agentic systems. Companion writing to Volume I, Understanding Agentic AI Systems.

8 posts Paired with Vol. I · Foundations → All posts →

  1. Jun 06 2026

    When to Use an Agent Framework vs Build It Yourself (LangGraph, CrewAI, and More)

    The honest answer is not "always" or "never." Build the raw loop yourself until you hit a specific named pain, then adopt a framework to solve that pain, not on principle. A decision diagram, a map of the frameworks worth knowing (LangGraph, CrewAI, AG2, LlamaIndex, OpenAI Agents SDK, Pydantic AI, plus the AWS, Microsoft, and Google platforms) and what each is good at, and the signals that tell you which side of the line you are on.

    · 12 min read

  2. May 26 2026

    Giving Your Agent Memory: A Minimal Implementation

    "Memory" is one word for four different problems your agent has. The conversation buffer, summarization, episodic recall, semantic retrieval, and key-value preferences, each built from scratch in raw Python with no framework, plus the decision guide for which one you actually need.

    · 12 min read

  3. May 26 2026

    Tool Calling From First Principles (Before You Touch LangChain)

    Function calling, demystified. The under-the-hood mental model of how a model "calls a tool," a 40-line runnable example with no framework, the four things that go wrong in production, and when reaching for a framework actually helps.

    · 10 min read

  4. May 24 2026

    The Agent Loop, Explained: Perceive, Decide, Act, Observe

    The four-move loop that turns a language model into an agent. A diagram, a worked example, and the failure modes that come from breaking each step.

    · 7 min read

  5. May 24 2026

    Build an AI Agent From Scratch in Python, No Framework

    A tutorial that builds a real AI agent in about 150 lines of Python, with no LangChain, no LangGraph, no CrewAI. Just the agent loop, two tools, memory, and bounded autonomy.

    · 12 min read

  6. May 23 2026

    What is agentic AI?

    A short, honest definition of agentic AI and how it actually differs from a chatbot or a generative AI app.

    · 2 min read

  7. May 20 2026

    Agentic AI Glossary: 40 Terms, Plainly Defined

    Forty core agentic AI terms in plain language, grouped from foundations to production: the agent loop, tool calling, memory, design patterns, guardrails, MCP, and more. A reference you can scan or cite.

    · 10 min read

  8. May 11 2026

    Agentic Coding Is Real. Here is the Mental Model Every Leader, Engineer, and Recruiter Needs in 2026

    A vendor-neutral mental model of agentic coding in 2026: what changed, the working definition of an agent, AGENTS.md, modes of autonomy, the MCP stack, and principles that have held up across two years.

    · 17 min read