Maintaining

This lesson is still being tested: it improves with learners' feedback. If something is unclear, it is the lesson that needs fixing, not you.

By the end of this lesson, you will be able to

write a README that lets you take your tool back up;
test that README with a new session;
keep a maintenance routine of ten minutes per month;
know when to archive a tool.

Why it matters to you

A tool you no longer understand is a tool you no longer dare touch. In six months, you will have forgotten where the data is, how to back it up, what was decided. The README keeps all that, on one page. And a small monthly routine avoids bad surprises: the backup that no longer works, the lost data, the change that broke everything.

Before you start


You need	Claude Code (app or terminal), in Manual mode, your tool with its specification and its Git history, and the README template (resource)
Cost	The agent subscription: Claude Pro at minimum, €18 per month excl. VAT billed monthly, or €15 per month excl. VAT with the annual plan of €180 paid up front; prices shown on claude.com/pricing on 24/10/2026
Duration	45 minutes, then 10 minutes per month
Reminder	Your tool’s backups contain its data: store them like the rest of your copies

Understand it in 3 minutes

What makes a small tool last:

Piece	What it keeps
The specification (lesson 1)	What the tool must do, and how to check it
The Git history (lesson 5)	Every version, with what changed
The README (this lesson)	How to use it, where the data is, how to change it
The backups (lesson 3)	The data, outside the browser

Few pieces, little maintenance. The CNIL advises evaluating the value of each dependency: some only do a few lines, and every added element increases the attack surface. A single-file tool, with no library, has almost nothing to update.

The CNIL also points out that documentation is crucial for maintaining a project: that is the role of the README.

Every change follows the same circuit: the specification first (if the need changes), a Git version, the change, all the tests, a new version.

Do it together

1Step 1: Write the README

In Claude Code, on your project folder, in Manual mode, use the request from the README template resource.

In our test on 24/10/2026, for the club’s loan logbook, the README came to 25 lines: the files, how to open the tool, where the data is (and what erases it), backing up and restoring, and how to ask for a change with a Git version before and after.

2Step 2: Test it

Copy the README alone into an empty folder, and open a new session on it:

Read only README.md. In 3 lines: where is the data kept, how do I back it up, and what happens if I open the tool in another browser?

In our test, the new session answered correctly on all three points, reading only the README. If the answer is wrong or incomplete on your side, fix the README, not the answer.

3Step 3: The monthly routine

Once a month, ten minutes:

export a backup of the data, and store it with your copies;
check that it imports again (in another browser, for example);
redo two or three tests from the specification;
look at git status: is everything saved?
write the date in the “Last maintenance” part of the README.

4Step 4: Archive what is no longer used

A tool that is no longer used: one last backup of its data, one last Git version, then put the folder in your archives and note it in your journal. You will be able to take it back up thanks to the README.

Your turn

The deliverable for module 12: your local tool, with:

its specification, up to date (lesson 1);
the tool, with every criterion checked (lessons 3 and 4);
its Git history, with clear messages, and a .gitignore (lesson 5);
no secret and no unnecessary personal data (lesson 6);
your going-online decision, written down (lesson 7);
a README tested by a new session, and the date of the first maintenance.

Resources to download

README template for your tool: the parts, the request to your agent, and the test with a new session.

Check your work

It worked if:

your README fits on one page, and a new session that reads only it answers correctly;
the monthly routine is noted in your calendar or your journal;
the “Last maintenance” part of the README is dated;
you know how to archive your tool the day it is no longer used.

Common mistakes:

a README written once, never updated;
backups never imported again: you find out too late that they don’t work;
adding libraries “to do better”, and having to maintain them;
changing the tool without going through the specification and a Git version.

Keep it and pick it up later

Add the monthly routine to your monthly maintenance (module 5, lesson 7).
Keep together: the specification, the tool, the README, and the backups folder.

Going further

optional

Module 13 offers a final project: your tool can be its starting point.

New words

4 words explained

Word	What it means
README	The user guide of a tool, kept in its folder
Maintenance	The regular checks that keep a tool useful and reliable
Dependency	An outside element the tool needs in order to work (a library, a service)
Archive	Store a tool that is no longer used, with what is needed to take it back up