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technical · Agentic AI & Tool Use

Build an AI agent you can read, limit and count, from a one-page plan to a run against a real model.

Write the system prompt, the tools, the loop and the trace yourself, then judge the agent by how many runs come out right.

By the end, you'll be able to:

  • Tell an agent from a chatbot or fixed workflow by what each does at a surprise
  • Write a system prompt in five parts and test it against fixed edge cases
  • Turn a Python function into a tool with a description and argument schema
  • Judge an agent by running its test set several times and counting correct runs
  • Read a trace forward to find the first wrong step and fix it there

From $9/month~7 hrs5 chapters20 lessons

“An agent is not a chatbot with tools. It picks each step from the last result. Here is how to build one and know whether it works.”

About this course

Who it's for

  • You write Python and have called an AI model from your own code
  • You want to build an AI agent you can understand, control and fix, without a ready-made framework hiding the steps
  • Your team has an AI system and needs to know whether it is really an agent, and whether it should be

What you'll need

  • You can read and write basic Python
  • You have called an AI model from code before, for example through the OpenAI or Anthropic API

What you'll be able to do

  • Tell an agent apart from a chatbot or a fixed step-by-step workflow
  • Decide whether a task is worth an agent by working out its cost and how often it would fail
  • Design an agent's instructions, tools and permissions, with a person approving any step it cannot undo
  • Write tool descriptions an AI model can use, and check every result that comes back
  • Build a working agent in Python and find what went wrong by reading its step-by-step log

Skills you'll practise

  • AI agent design
  • System prompts
  • Tool calling
  • Checking AI output
  • Human approval steps
  • Python
  • Reading run logs
  • Cost and risk checks

How long it takes

About 7.5 hours in total

  1. Chapter 1 · What is an AI agent, and when is it worth building one?1.5 hours
  2. Chapter 2 · What does an agent need before you write its code?1.5 hours
  3. Chapter 3 · How do you make a model's output reliable enough to act on?1.5 hours
  4. Chapter 4 · How does an agent use tools?1.5 hours
  5. Chapter 5 · How do you build, run and debug the agent?1.5 hours

What's included

  • 20 lessons
  • 80 readings
  • 20 worked examples
  • 60 exercises
  • 40 quick checks
  • 20 common myths
  • 20 quizzes
  • 5 end-of-chapter checks

Curriculum

5 chapters, 20 lessons

The full expedition — every chapter and lesson. Tap a chapter to expand. Lessons unlock when you start.

    • What Are the Parts of an Agent, and Where Does It Keep What It Knows?
    • How Do You Write a System Prompt That Holds Up?
    • How Do You Limit What an Agent Can Do?
    • How Do an Agent's Parts Pass Data Safely to Each Other?
    • Why Does the Same Question Get Different Answers?
    • How Can You Check What the Model Claims?
    • How Do You Get Answers Your Code Can Read?
    • How Do You Know Whether Your Agent Works?
    • How Does a Python Function Become a Tool?
    • How Do You Describe a Tool So the Model Uses It Correctly?
    • What Happens When the Model Calls a Tool?
    • What Should Happen When a Tool Fails?
    • How Do You Record Every Step an Agent Takes?
    • How Do You Write the Agent Loop?
    • How Do You Run Pathfinder and Approve Its Actions?
    • How Do You Find What Went Wrong in a Run?

Career

Where this course can take you

The roles this course maps to, and the skills you can list on your resume and LinkedIn once you finish it.

5
roles it maps to
AI EngineerML EngineerSoftware EngineerPlatform EngineerPrompt Engineer

Skills you will master

Ready to paste into your resume or LinkedIn profile once you have finished the course.

  • Agent design and scopingagent architecture
  • System prompt writing and agent stateprompt engineering
  • Tool definition and tool callingfunction calling
  • Agent permission control and safe hand-offsAI safety controls
  • Agent evaluation and output checkingLLM evaluation
  • Agent loop implementation, tracing and debuggingagent orchestration

Questions

Before you commit

An agent is a loop: it observes, reasons, branches, invokes a tool, reads the result and decides again until a stated condition ends the run. A chatbot answers a turn and stops. ORBIT names the five things any agent does (Observe, Reason, Branch, Invoke, Terminate), and SPINE names its five components (State, Perception, Identity, Navigation, Execution).

No. You build the agent loop in plain Python so every part stays visible: the loop, the tool registry, structured output and the traces. Frameworks come up once, as context. You should already be comfortable calling an LLM API and writing Python.

ReAct alternates reasoning and acting: the model decides the next step, calls a tool, reads the result and decides again. Chapter 5 has you wire that loop from scratch, with a step budget, a stated reason for stopping and a record of every step, so you can see why a run ended where it did.

Chapter 4 treats every tool result as an observation the agent has to parse: a result envelope, an error envelope the model can read, and timeout and retry policies that never repeat a side effect. Chapter 5 adds traces, so when a run goes wrong you can find the step where it drifted and replay it.

Pathfinder, a supply-chain search agent. It takes a sourcing question, searches a mock supplier API, compares candidates on lead time and risk, and drafts a recommendation that a sourcing analyst approves before anything happens. You sketch it in chapter 1, blueprint it in chapter 2, and build and debug it in chapter 5.

More often than most teams expect. Lesson 1.3 gives you a test for whether a task needs an agent at all. A fixed workflow or a single model call is often cheaper, faster and easier to debug, and the course shows how to tell the difference before you build.

With boundaries set before the first run: a permission surface that lists what the agent may touch, constraints enforced in code rather than only in the prompt, and a person approving any consequential action. Every run also leaves a trace you can read afterward.

Engineers who have called an LLM API and written Python and now want to build agents they can reason about. It is relevant to roles such as AI engineer, LLM application developer and AI solutions engineer.

Tutorials usually show an agent that works once. Here each chapter pairs one framework (ORBIT, SPINE, DEPTH, GRIP, FORGE) with the failures it prevents, and you practice it on the same project. Vendor facts, such as API names and model versions, are checked against current documentation.

Python 3.12 or newer with uv, Pydantic for structured output, a small FastAPI app that serves the mock supplier data, and the tool-calling interfaces of the OpenAI Responses API and the Anthropic Messages API. The tools chapter also covers the Model Context Protocol (MCP).

No. You should be able to write a Python function, read JSON and use a terminal. Having tried a chat model is enough; the course explains tool calling, structured output and the agent loop from the start.

No. You write the loop, the tool registry and the trace yourself in plain Python, using a model API directly, so you can see what each part does. Pydantic is used to define argument and answer shapes.

Pathfinder is the agent you build across the course. It searches a mock supplier catalog, answers with supplier ids it can ground in tool results, and has one side-effecting call that waits for your approval at the terminal.

Most of the build and testing runs offline with a scripted model that replays fixed replies. The final chapter runs against a real model, which needs an API key; the runs are short.

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From $9/month