When should I use The Margin Sentry?

ROAS looks stable but profit is drifting, or a supplier, shipping, or price change just landed. That's the diagnostic trigger. Once installed, ask Claude for the outcome ("catch the skus that went unprofitable since the last run") and the skill kicks in automatically.

How does The Margin Sentry work under the hood?

The Margin Sentry is part of the Store Loops mechanism in Sid Chaudhary's gtm-skills repo. When invoked, Claude reads the SKILL.md, pulls your shared product-context (ICP, brand voice, scoring model), and produces a structured output. No prompt engineering on your side.

Do I need Claude Code to run The Margin Sentry?

Claude Code is the fastest path since it auto-loads local skill folders. The same SKILL.md also runs in Claude Desktop and claude.ai Projects - upload the zip in Capabilities. See the install options below for both paths.

How is The Margin Sentry different from just prompting Claude?

A skill is a folder with a SKILL.md file plus reference material - real methodology, frameworks, and benchmarks Claude loads on demand. A prompt is text you paste every time. With The Margin Sentry installed, you ask for what you need in plain language and Claude runs the right process without you re-explaining it.

All skills

Store Loops

The Margin Sentry

Q: Is The Margin Sentry really free?

Yes. The full gtm-skills repo is MIT licensed on GitHub. Clone it, fork it, modify it. Running the install command (npx skills add sidchaudhary/gtm-skills/skills/store-loops/the-margin-sentry) pulls it straight from GitHub into your project's .claude/skills/ folder. No signup, no build step, no gated tier.

Catch the SKUs that went unprofitable since the last run

terminal

$ npx skills add sidchaudhary/gtm-skills/skills/store-loops/the-margin-sentry

No signupMIT licensedView source

About

What it does

Catch the SKUs that went unprofitable since the last run

You'll know it's time when...

ROAS looks stable but profit is drifting, or a supplier, shipping, or price change just landed.

How it works

Run it in three steps

0110 sec

Install

Copy the install command above and run it in your project.

02instant

Ask Claude

Ask for what you need in plain English, no prompt tuning required.

03seconds

Get the output

Claude returns a structured artifact aligned to your ICP and voice.

When to reach for it

ROAS looks stable but profit is drifting, or a supplier, shipping, or price change just landed.

What it does

Full SKILL.md preview couldn't load right now. View source on GitHub.

Part of the Store Loops pack

This is one of 9 Store Loops skills. They chain - the order you run them in changes what you get, and running one in isolation usually means re-answering setup another skill already captured. Claude Skills for Shopify walks the whole pack in the order the skills actually chain.

Install

Two ways to run it.

Pick your Claude surface. Both paths take under a minute.

Prefer one command? npx skills add sidchaudhary/gtm-skills installs the whole set via the community skills CLI. If you'd rather not run a third-party CLI, use either path below to install the ZIP directly.

claude.ai or Claude Desktop

Upload as a zip in Capabilities

Paid plan

Open Settings, then Capabilities
Turn on code execution if it isn't already on
Upload the .zip you downloaded

Requires a Pro, Max, Team, or Enterprise plan. Not available on the Free plan.

Claude Code

Drop the folder, it auto-loads

Any plan

Unzip the download
Drop the folder into ~/.claude/skills/ (or .claude/skills/ in a project)
Claude Code finds it automatically

$ ls ~/.claude/skills/
your-new-skill/

Questions about The Margin Sentry

Everything you need before installing, plus how the skill actually behaves once Claude picks it up.

Reruns the contribution-margin stack on a cadence and reports crossings rather than levels: which SKUs breached your CM2 floor, which recovered, and which cost line moved. Splits losing-before-ads from losing-only-because-of-ads, and withholds any verdict on a SKU with missing COGS. It's a Claude Agent Skill - a folder with a SKILL.md file and reference material - so Claude loads the methodology on demand when you ask for what you need in plain language, instead of you pasting a template.