Mods: customize Claude Code

Make a small Claude Code mod that adds a useful reminder above your prompt. You will try it in one session, check its behavior, and save a reusable copy only after it works.

Before you start

• Claude Code CLI version 2.1.287 or later; run claude --version in your terminal to check.
• A folder for experiments that is separate from your website project, and a terminal open in that folder.
• A short reminder to display, such as “Check the phone layout before finishing”. Managed plugin rules may restrict what you can load.

Want to do it yourself?

Difficulty

6 out of 10

Estimated completion time

30–60 minutes

Skills you’ll need: Inspect customization instructions, change one setting at a time, and verify you can restore the previous behavior.

I’ll do it myselfI’d rather get help

How this helps your brand

A visible reminder can reinforce a maintenance habit such as checking phone layouts. Testing and saving a narrow mod gives you a reusable cue without mistaking it for an enforced quality check.

1. 1

   Step 1: Choose one visible change

   Start with a reminder strip, rather than a mod that changes commands or permissions. Write the exact sentence you want to see and where it should appear. For a website project, a useful first sentence is “Check the phone layout before finishing”.

   Mods are code with the access Claude Code has on your machine. Review what Claude creates before keeping or installing it. A reminder is a convenience, not an enforced rule.

2. 2

   Step 2: Ask Claude to build a session experiment

   Run claude in your experiment folder. Paste the prompt below after replacing the bracketed fields. Ask it to explain the files and the events the mod uses before enabling it.

   The official mod tutorial supports describing a mod in ordinary language. Claude can create a temporary plugin and offer hot reload. Approve that offer after checking that the proposed behavior matches your request.

3. 3

   Step 3: Check the reminder in the running session

   After Claude finishes its turn, look above the prompt for your exact reminder. Send a harmless follow-up, such as “Explain what this mod displays without changing any files”. Check the strip after that turn too.

   Ask for one wording change, such as adding your project name. Confirm the new text appears through hot reload and the old text does not remain as a second strip.

   Illustrated exampleCheck the first display, then the replacement

   Illustrated session

   1 · First display

   Check the phone layout before finishing

   ❯ Your prompt appears below the strip

   Ask to add “Northline” · hot reload

   2 · After the wording change

   Northline: Check the phone layout before finishing

   ❯ One updated strip above the prompt

   Try a harmless follow-up

   “Explain what this mod displays without changing any files”

   • The strip returns after the next turn.
   • The old wording is replaced; there is only one strip.

4. 4

   Step 4: Recover if nothing appears

   Copy the error or describe the missing strip. Ask Claude to validate the plugin with claude plugin validate [mod folder] and check its implementation against the type declarations generated for your installed version.

   If validation passes but the drawing is absent, the vendor tutorial recommends starting with claude --debug and checking for a render validation error. Share the relevant error with Claude, remove private values, and ask it to fix just that error.

5. 5

   Step 5: Save and reload a reusable copy

   A mod generated for a hot-reload experiment is temporary. Ask Claude to copy the entire plugin folder to a permanent folder you choose before ending the session, and to tell you the saved path.

   From your terminal, start a new session with claude --plugin-dir [saved mod folder]. Use the real path without brackets. Confirm the reminder appears again. For this first mod, stop there; distributing a plugin is a separate decision.

   Illustrated exampleKeep the whole plugin, then prove it reloads

   Session experimentTemporary plugin folder

   Copy the
   whole folder

   Permanent copy~/claude-mods/phone-reminder

   Start a new session from your terminal

   claude --plugin-dir ~/claude-mods/phone-reminder

   Confirm the reminder appears again in this new session.

Create a small Claude Code mod called [mod-name] that displays this reminder above the prompt: [exact reminder]. Use the mods API for my installed Claude Code version. Explain the plugin files and the events you will hook before enabling hot reload. This mod should only draw the reminder; it must not rewrite prompts, tool calls, permissions, or project files. Validate the plugin and help me check the first display and a wording change. When it works, ask me for a permanent folder, copy the whole plugin there, and give me the exact command to load that copy in a new session.