Lesson 3 of 6 · 14 min · Checked on 6 October 2026
Projects, custom instructions and memory
By the end of this lesson you will be able to:
- Tell apart custom instructions, projects and memory between conversations
- Write short custom instructions that apply to every conversation
- Organise a subject into a project with its own files and instructions
- See, correct and delete what the service has stored about you
Carlos repeated himself every week
Carlos is the treasurer of the parents' association at the school. Every Monday he opens the AI assistant and types the same introduction: "Reply in plain English, short. I am the treasurer of a parents' association." Then he pastes the association's rules again, so that the AI knows the rules on membership fees.
One day, at the end of a conversation about his daughter's birthday dinner, the AI replies: "As treasurer, you may want to include this in the association's budget." He did not mention the association in that conversation. How did it know?
Carlos was mixing up three things that AI services have, and that serve different purposes.
Three different things
| What it is | Example | Applies to | |
|---|---|---|---|
| Custom instructions | General rules about you and how you want answers | "Reply in plain English, short." | Every conversation |
| Projects | A space for one subject, with its own instructions and files | "Parents' association", with the rules and the meeting notice template | Only the conversations inside that project |
| Memory | Notes the service keeps about you, from your conversations | "He is the treasurer of a parents' association." | Future conversations, until you delete them |
Think of a new employee in a shop. The custom instructions are what you tell them on the first day: "here we serve everyone patiently". The project is the filing folder for one subject: open it and everything is there. The memory is the notes they take by themselves in a notebook. They are handy, but it is worth glancing at what is in there from time to time.
It was the memory that reminded the AI that Carlos is a treasurer.
Custom instructions: say it once
Put here what you want in every answer: the language, the length, the tone, what to avoid and who you are, in general terms.
Always write in plain English. Short answers: 10 lines at most, unless I ask for more. No emojis. When you are not sure of a fact, say that you do not know. I work in a small shop selling regional products and I am not technical: explain difficult terms.
Tip
In the custom instructions, "I work in a shop" or "I am a teacher" is enough. Do not put your full name, address, tax number or company name: the AI does not need them to answer well.
Projects: one subject, one folder
A project is for a subject you come back to often: the parents' association, the shop, the work on the house, a year's classes. Inside it you put:
- Instructions for the subject: "You help the treasurer of the parents' association. The school year runs from September to July. Membership fees are yearly."
- Reference files: the rules, the meeting notice template, the minutes of the last general meeting (with no personal data).
Every new conversation inside the project already knows all of this. Carlos writes "Prepare the notice for the October meeting" and it comes out in the template's format.
Tip
One project per subject. If you mix the shop and the association in the same project, the AI mixes the rules of one with the rules of the other.
A project's files are stored in the service. The rules from Level 1, lesson 5 apply: the list of members, with names and emails, does not go in.
Memory: what the service keeps about you
Some services take notes about you: what you do, what you like, how you like your answers. Others can also look up old conversations. This saves you repeating yourself, but it has three risks:
- It keeps what it should not: a health problem you mentioned once, a customer's name.
- It mixes subjects: your daughter's party turns up in a work conversation.
- It goes out of date: you changed jobs and the AI still talks about the old one.
So, once a month, open the memory list and read it. Delete what is wrong or surplus. If you prefer, switch the feature off. For a sensitive subject, some services have a temporary chat, which does not use or feed the memory.
Watch out
Do not let the memory keep customer data. If you use AI for work with customers, swap the names for labels ("customer A") and, for those subjects, switch the memory off or use a temporary chat. And do not trust "forget that": the AI may reply that it forgot and the note may still be stored. Always check in the memory list, in the settings. Having customer data stored in an outside service without need is what the GDPR asks you to avoid. This is not legal advice.
On a work account, whoever manages the accounts may have decided which features are switched on. Ask before changing anything.
How it is done today
This is how it looks on 6 October 2026; your screen may differ.
Each service gives these three things different names, and the names change with updates. Custom instructions may appear as "custom instructions", "personalisation" or "preferences". Projects may be called "projects", "spaces" or have a house name. Memory almost always appears as "memory".
The path is similar in all of them: click your name or your photograph, in a corner of the screen, open the settings and look for instructions, projects or memory. Some features only exist in certain versions or in certain countries. To find out what each version includes, see the Current state page.
Exercise
How I know it worked answers in your format without having to repeat it, a project that already knows the subject and a memory that you have seen and cleaned.
If it didn't work
- Can't find the settings? Look for your initial or photograph in a corner of the screen, or a cogwheel symbol.
- Is the AI ignoring the custom instructions? Check that you saved them and open a new conversation: in general, they only apply from then on. Short instructions with no contradictions work better.
- Does your version not have projects? Keep the instructions and the reference text in a document and paste them at the start of each conversation on that subject.
- No memory in your version? That is fine: you have nothing to clean.
Videos
Demonstrates Claude Projects with four company documents: Claude cross-references them and, when the answer is not in the documents, says it could not find it.
An official Anthropic video: create a project, define project instructions and manage the knowledge files Claude draws on.