Cart Cop

A Claude Code skill that makes you defend a purchase before it approves one.

Most budgeting tools record a purchase after it happens. This one gets in the way beforehand. It asks what exact task your current gear is failing at, checks the answer against what you already own, and prices the buy as a delay to a goal you named yourself.

Grounded in Morgan Housel's Psychology of Money. It is not an automatic no. If something genuinely solves an active bottleneck and is built to last, it says yes.

Install

In Claude Code, as a plugin. This is the one to use: it brings the skill and the /cart-cop-init command.

/plugin marketplace add jainulabudeenm/cart-cop
/plugin install cart-cop

Or from npm, if you want the skill in Claude.ai or anywhere outside Claude Code. This installs the skill on its own, without the slash command.

npx cart-cop

Add --project to install into the current repo instead of your home directory, so you can commit it and share it with a team.

Use

Just say what you want to buy.

> I want to buy a new mechanical keyboard.

On first run it interviews you once, five short questions, and saves a profile to ~/.claude/cart-cop/profile.md: what you own, what you are circling, and what you are saving for. Everything after that is instant.

Re-run /cart-cop-init any time to update it.

What it actually does

Three rules it will not bend:

• The Forecasting Error. Buying specs for who you think you will be in three years is a mathematical error, not foresight.
• The Struggling Test. The only valid reason to upgrade is that your current tool is failing you today. Not soon. Today.
• The Aging Gear Clause. Age is not a failure state. Slow is not broken. Old gear has to be proven functionally broken, not merely old.

And the part that does the real work: every rejection converts the price into a delay to a specific goal from your profile. "This is 320 dollars, which is five weeks added to your emergency fund" is harder to argue with than "you do not need it".

One item at a time. It will refuse to discuss a list, because a batch discussion is how three purchases get approved on the strength of one good argument.

The profile

~/.claude/cart-cop/profile.md, in your home directory rather than a project folder, so it cannot end up in a git repo by accident. It is plain markdown. Open it and edit it whenever you like. See profile.example.md for the level of detail that produces useful verdicts.

The skill also offers to update the profile as it learns, so it gets sharper the longer you use it.

Not for

Investment advice, retirement modelling, or budgeting. It reasons about one purchase against goals you already set. It does not set them.

License

MIT