WEBVTT

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So as you work on projects with Claude
Code, from time to

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time,
you might wanna use Claude Code to perform

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because, of course,
it can also take a look at your code

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wrote, I guess,
and give you some feedback on that.

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So you might wanna send a prompt like this
to Claude Code or

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maybe a more elaborate one where you
describe in a bit

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more detail how that code review should be
performed.

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The problem with this approach is,
however, that you probably

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wanna perform code reviews over
and over again from

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time to time. Not all the time,
but maybe every day or so.

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So you will probably repeat
that prompt from time to time, and

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sentence, that's not too bad, but what
if it should be more

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elaborate?
That's where custom commands come

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into play. Just as you can add agents
and skills

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to your Claude setup,
you can also add custom commands, which

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are in a nutshell just reusable prompts.

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You can add them locally in your project
as I'm doing it here, or again

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globally in your user Claude folder.

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And a custom command
is really just a prompt

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which could look like this, but there
are a couple of things going on here, of

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course. And of course,
you also find this command attached.

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Let's start with the metadata. This
is entirely optional.

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You don't need it. In its simplest form,
a custom command could look like this,

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just a prompt,
but you can give it a description

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show up when you cycle through your
commands and you can

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restrict the tools
that can be used by Claude Code after you

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invoked this command. By default,
it can use all the tools of

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the surrounding context, so all the tools,
for example, if you use it in

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the main agent. But
if you add allowedTools,

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tools you specify here.
So for a code review command, I

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might wanna narrow this down to just read
access so that

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it can't write any files.
And then you have your prompt here.

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Now this is a bit more elaborate prompt
here also

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because of this weird thing. Your commands

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can, but don't have to accept arguments.

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You can use this special $arguments
placeholder

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here and this field will be replaced with
any

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arguments,
any input you passed to your command,

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show you how you can do
that in just a second.

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So this will be replaced with your actual
arguments, and this allows you to

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build flexible dynamic commands just like
functions in a

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programming language,
which also can accept parameters.

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Here, for example,
I expect to get a mode and

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then in my prompt I tell Claude Code what
to do based

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on the value mode has,
and maybe I write it like this.

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So if mode is bugs,
it should just look for bugs.

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If it's security,
it should look for security.

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I also wanna allow for combined modes to
look for bugs and

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security issues, for example.
And then I got some additional

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down here, and it's just a prompt.
You can tweak this however you want and

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you can build any commands you want.

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A command is simply a markdown file in the
command's folder.

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With your command defined,
you can close your Claude

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session and start a new one.
You must do this to make sure

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are properly loaded. And then
if you type a forward slash,

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your command will show up here amongst all
the other

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commands.
They will not be auto discovered by Claude

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be executed by Claude. They
are meant to be executed by you.

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So that's how that works.
And therefore with that, I can

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choose this code review command here
and I could now hit enter

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or I could provide some arguments.

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Because remember, you can use arguments in

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there. You don't have to, but you can.

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So here I could say bugs, security

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because these are the kinds of values I
accept in my prompt

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here.
And if I now hit enter Claude Code will go

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ahead and use that prompt
and therefore now look

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for bugs and security issues, and
that prompt was executed behind

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the scenes and that's, of course,
therefore an easy way of reusing such a

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prompt.
And now it explores my code base

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hopefully generate a good report about any
potential

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issues it finds in there. So here we go.

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I got my report and further above I also
have

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some details on all these findings.

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And of course,
you should still take a look at them.

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They're not necessarily all issues,
or in our case here,

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of course, the app is also not done yet.

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But of course,
it's good to have these findings,

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decide whether you want to act upon them
or not.

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So for example,
here I don't worry too much about this

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to a public note page because I haven't
worked on that page

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yet. That's a feature that's yet to come.

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So here in my case, I actually added a

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.inf file. Well,
I did it earlier already

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off secret in there with, uh,
at least 32 characters long

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string that is needed by better off.

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And I added this DB path variable since
that was one of the

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findings here that I have a hardcoded
relative DB path and I

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don't want that.
I therefore crafted a new response prompt

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I tell it to tackle these three problems.

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Actually, I added one more
and told it to update use

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state to use common best practices.

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And with that,
I'll switch to plan mode

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And of course, now this
is a new prompt so the old tool

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restrictions from the custom command no
longer apply.

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It now has full access to all tools again,
and it can therefore make

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that plan and then later also implement
the plan.

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So here we go.
It presents me with a plan and

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I'll accept that and let it continue.

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So with that done, this all

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still seems to work.
I can go to the dashboard, can log out,

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can log in, and add new notes
and therefore the app is working

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like before,
but hopefully now with less problems.

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Obviously,
you should still always also manually

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AI can make mistakes
and it certainly doesn't give you the best

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code all of the time. But with that,
we can now move on.