Claude is good at the part of grocery shopping that happens before you leave the house: turning a week of meals into one list, in supermarket units, with everything you already own stripped out of it. It is bad at everything that requires eyes or a receipt - it cannot see your fridge, does not know what your shop charged this week, and cannot tell you whether the chicken is still fine. Give it an honest inventory and it removes the two habits that cost the most: buying what you already have, and buying for meals you never cook.
How much is actually leaking here?
The US Environmental Protection Agency put a number on it in April 2025: for a household of four, food that gets bought and then thrown away costs $2,913 a year, about $56 a week. That is not a moral failing, it is a planning failure with three causes: shopping without a list, forgetting what is already in the cupboard, and buying for a week you did not actually have time to cook.
All three happen before you reach the shop, which is exactly where a chat window can help. Nothing below requires an app, a barcode scanner or a smart fridge.
What do you give it before it builds a list?
A list is only as good as the inventory behind it. Five inputs, and the third is the one people skip:
- Who is eating, and how many nights. Two adults for five dinners is a different shop from four people for seven.
- The week you actually have. Which nights are 25 minutes, which night you can cook properly, which nights somebody is out. A plan built for an imaginary week gets abandoned by Wednesday and the food rots.
- What is already in the house, honestly. Open the cupboard and the freezer and read them out. Half a bag of red lentils, four eggs, a jar of harissa with two spoons left, the bag of frozen peas behind the ice. This is the single input that changes the bill.
- What is about to turn. The spinach going limp, the chicken with two days on it. These get planned first or they get binned.
- Where you shop and how. One delivery or a walk-round, and which supermarket, because pack sizes differ and recipe grams do not exist in a shop.
How do you get one list instead of a recipe-unit wish list?
The failure mode is a list written in recipe units: "150g crème fraîche" when the shop sells a 300g tub, "2 tbsp tomato purée" when the shop sells a tube. Ask for supermarket units and aisle order, and make it subtract your inventory rather than politely mention it.
The last two rules matter more than they look. Ask for a total and Claude will produce a confident one built from prices it has never seen, and the plan starts carrying a number nobody can act on.
The reason to load a skill rather than re-paste the prompt is the inventory. Margot keeps your staples, your household size and your hard nos between sessions, so week two starts from "what changed" instead of you reading the cupboard out again from scratch.
Get Margot →What do you cook from the three sad vegetables?
This is the prompt that actually removes waste, because it runs at the point of decision rather than at the start of the week. Keep it short enough to use standing at the fridge.
Option three is the one that earns its place. Half of what gets wasted is not wasted on the night it goes off - it is wasted because nobody decided anything that evening and it sat there for four more days.
How do you stop running out of the basics?
Separate from the weekly shop, there is a standing list: the things whose absence stops a recipe dead. Build it once and the emergency trip to the shop for one tin mostly disappears.
Where Claude fails at this
- It cannot see your fridge. Everything it knows about your inventory is what you read out. A plan built on a half-remembered cupboard produces a list that is wrong in both directions.
- It does not know what anything costs. No access to your supermarket's prices, no idea what is on offer this week. Any total it gives you is invented, which is why the prompt above bans them.
- Storage times are general, not yours. Its "keeps 3-4 days" is a reasonable average, not a reading of your fridge temperature or how long the chicken sat in the car. For cooked leftovers, the USDA reference is 3-4 days refrigerated or 3-4 months frozen - use that, not the chat window.
- It cannot judge whether something is still good. Smell, texture and the date on the packet are yours to check. Never let a plan talk you into cooking something you would otherwise have thrown out.
- It cannot read the label. Allergen statements and "may contain" lines change when manufacturers reformulate, and it cannot see the packet in your hand. If somebody in the house has a diagnosed allergy, the label is the authority.
- It will not tell you the plan is too ambitious. Ask for seven dinners and you get seven, whether or not your week has room for them. Give it the honest week or it will plan for the one you wish you had.
Margot works from the cupboard outwards. Paolo works from the week inwards: the seven-day plan, the Sunday prep session scheduled around your oven, and the list that falls out of it. Most households only need one of the two - start with whichever end of the problem is currently failing.
Get Paolo →How do you install the skill?
A KissMySkills skill is a ZIP file with a SKILL.md at its root. In the Claude desktop app, open Customize → Skills, add a skill, upload the ZIP, and toggle it on.
Skills work on every Claude plan - Free, Pro, Max, Team and Enterprise. The real requirement is code execution: switch on Code execution and file creation under Settings → Capabilities. On Team and Enterprise an owner can disable it for the whole organisation, which is why the Skills menu sometimes looks greyed out.
If you cannot enable code execution, or you work in ChatGPT or Gemini, open the SKILL.md in any text editor and paste its contents into custom instructions. Same rules loaded, you just re-paste them per workspace.
In summary
Read the cupboard out before you ask for anything, make it subtract what you already own, and ban price estimates and recipe units from the list. The cupboard end of the problem: Margot ($19). The week end: Paolo ($19). Both work in Claude, ChatGPT and any AI chat, with a 30-day money-back guarantee. Neither can see your fridge, price your shop, or tell you whether the chicken is still fine.
Margot - Grocery & Pantry Manager AI Skill
Holds your staples, your household and your hard nos between sessions, plans around what is already in the cupboard, and hands you one list in supermarket pack sizes and aisle order.
KissMySkills is a marketplace of 2,000+ AI skills, 300+ prompt packs, 100+ agents & free tools for Claude, ChatGPT & any AI chat. 30-day money-back guarantee.
