You open ChatGPT or Claude and ask for tomorrow's lesson. The answer shows up in a minute. Then you close it, because it does not know that yesterday's class stopped halfway, that Thursday is only forty minutes, or that you already taught this topic in March to a different group.
The limit is not the assistant. It is the blank chat. Every conversation starts again without your classes, your calendar, or the plans you have already written.
GapFiller connects to the AI you already use. You plan lessons in the place where you think, on the classes and plans of your actual year.
The method, starting from a blank chat, is in How to plan a lesson with ChatGPT. Below is what changes once the lessons are already in the planner.
The chat and the planner cannot stay apart
A lot of teachers already do the job twice. The syllabus lives in a document. Ideas, questions, and adaptations live in a chat. Then comes the copying, and by November neither place remembers October.
A planner is the home for lessons: the ones ahead, the ones you have taught, the classes, the calendar. The assistant is how you think quickly, in your own words. Keeping them apart means explaining the context again every evening.
When GapFiller is connected to ChatGPT or Claude, the conversation starts from lessons you already have. Not from "write me a lesson on the French Revolution" spoken into an empty window.
What you actually ask
You do not need a prompt from a manual. You talk the way you would talk to a colleague who has read your plans.
- Prepare tomorrow's hour from where this class actually is.
- The same topic, for the other section: shorter, with a different example.
- We lost two hours last week. Show me how to pick it up without starting over.
- Before the test, what I still have not closed.
- Rewrite this passage as a question that gets them in, not as a textbook summary.
That is the whole planning job: prepare, adapt, recover, decide where to stop. You do it with the assistant already on your phone, not with a new program to learn.
This is not a lesson generator
A lesson generator starts from a subject and an age. It returns a generic sheet, the same one for anyone who teaches that topic. Then you throw it out, because it does not know your year.
Here the assistant is yours. ChatGPT, if that is where you think. Claude, if that is where you think. GapFiller does not ask you to change the habit, and it does not take your place: it works from what you have already decided to teach. The choice, and the moment you say "not today, I am keeping this for Friday," stay yours. We say more about that in Education is not automation.
An ordinary evening
Tomorrow you have history with the second year. The lesson is already on the calendar: a title, a class, and the text you sketched weeks ago. You open the assistant and say only this.
Tomorrow, history with 2B. We were on the causes of the Revolution. I have forty minutes. Open with a question, tell me what to pick up, and where to stop.
The answer is about that class and that point in the course, not a lesson found on the internet. You read it, cut it, and make it yours. The plan stays where you keep the year.
If the plans are still scattered across files and notebooks, put them in one place first. A practical guide is How to organize lesson plans.
Connect the assistant you already use
The step is short.
- The lessons live in GapFiller: calendar, classes, text you wrote.
- You connect ChatGPT or Claude with the same account.
- You ask about the class you actually have tomorrow.
The steps are in the guide Ask ChatGPT or Claude about your lessons.
From there you plan where it already feels natural to talk, and the lesson archive stays in one place. If you switch assistants next year, the plans do not leave with the chat. They stay yours.
To try it, open GapFiller and connect the assistant you already use to prepare your hours.