Agents, Not Chatbots
The mental model behind agents that do work, not chat.
Most people who say they use AI at work mean this: they open a chat window, paste something in, read the answer, and copy it somewhere else. Forty times a day. The AI helped with the typing. The person is still doing the job.
This course is about the other thing. Systems where the work happens whether you are at your desk or not. By the end of this lesson you will have one mental model, and you will be able to point at any AI system and say which parts are plumbing and which part is the brain.
Chatbots answer. Agents act.
A chatbot is a conversation. You bring it a task, it responds, and the loop ends with you. Useful, but it scales exactly as far as your attention does.
An glossary term, activate for a definition is a job description. It watches for work, decides what to do with each piece, and does it. The loop ends with a result, not a reply.
The difference is not the model. The same Claude that drafts your email in a chat window can run inside an agent. The difference is where the human sits. In a chat, you are between every input and every output. In an agent, you set the rules once and step out of the loop.
The three boxes
Every agent you will build in this course, and almost every agent you will ever see, is three boxes.
Trigger. Something happens. An email arrives. It turns 7am on Monday. A form gets submitted. A row lands in a spreadsheet. Triggers are dumb on purpose. They fire, that is all they do.
Agent. The model looks at what came in and makes a decision. What kind of email is this. Does this lead match our customer profile. Which numbers in this report changed enough to mention. This is the only box with judgment in it.
Action. Something concrete happens in the world. A draft is saved. A row is written. A Slack message goes out. Actions are dumb on purpose too. They execute exactly what the decision said, nothing more.
Here is the model on one line:
Trigger (something happens) -> Agent (AI decides) -> Action (code executes)
That is the whole diagram.
Checkpoint A workflow reads every new support ticket and posts it to Slack with the customer's plan tier attached. No AI involved. Is it an agent?
A real one, taken apart
Here is an agent that runs on a real inbox at our company. Yesterday it processed 114 emails before anyone had coffee.
- ReadA new email lands in Gmail
Every arrival fires the workflow once. The trigger has no opinions.
- ThinkClaude reads it
One question, in effect: what is this and what should happen to it.
- DecideOne of four categories comes back
urgent | needs_reply | newsletter | invoice
- ActA switch routes on the category
Four exits. Each one is dumb and deterministic.
- Check9 of 114 reached a human
The other 105 were handled and nobody read them.
Step 5 of 5. Check: 9 of 114 reached a human
Urgent posts to a Slack channel within a minute. Needs a reply gets a drafted response saved to Drafts, and a person reads it before it goes anywhere. Newsletters get archived. Invoices get labelled and forwarded to bookkeeping.
Nine of 114 needed a human. The other 105 were handled, and nobody read them. That is the entire pitch for this course in two sentences.
The anti-pattern, for contrast
Now the same job, the way most people do it.
You are the trigger and the action
Open inbox. Read an email. Copy it. Switch tabs. Paste into a chat window. Type "write a polite reply saying we will get back to them Thursday." Copy the answer. Switch tabs. Paste. Send.
Eight human steps, about 90 seconds. Times 40 emails.
The agent is
An email arrives. The model picks a category. A draft is saved.
Zero human steps until a person opens Drafts and reads nine of them.
If you recognize yourself here, good. Every build in this course starts from exactly this position.
The mistake, and the fix
Here is the part most courses edit out.
The first version of that triage agent used a one-line instruction: "Classify this email." Reasonable, right? Here is what came back on three real emails:
Email: "Invoice #4471 attached, due July 25" -> "Business"
Email: "URGENT: server down, customers affected" -> "Work email"
Email: "Our July newsletter: 5 automation tips" -> "Informational"
Not one usable label. "Business" is not a category the switch knows. Nothing was wrong with the model. It answered the question it was asked, and the question was lazy.
The fix took two minutes:
Classify thisinto email.exactly one of: urgent, needs_reply, newsletter, invoice. Respond with only the label. Example: "Payment reminder: #2210 due Friday" -> invoice
Name the allowed categories, say what happens to each, give one example. That is it.
Hold onto that experience. When your agent gives you garbage in lesson 5, you will not think the model is broken. You will ask what you failed to tell it.
Recap
An agent is a trigger, a decision, and an action. The AI owns the decision and nothing else. If you are copying and pasting into a chat window, you are the trigger and the action, and that is the hour a day we are here to get back.
Next lesson: how to pick the right job to automate, and why the obvious candidate is usually the wrong one.
Which of these is an agentic workflow rather than a chatbot session?
In the Trigger, Agent, Action pattern, which part should the AI own?
You answer 40 emails a day by pasting each one into a chat window and copying the reply back. What is that?
A workflow becomes agentic when...