Purpose
Estimates customer acquisition cost (CAC) for each traffic source by combining the number of new-customer orders attributed to a landing page / referrer with a configurable ad spend input per source. Output answers: "for every dollar spent on source X, how many new customers did we acquire and at what unit cost?" Read-only — no mutations. Provides the data foundation for paid-media budget reallocation.
Prerequisites
- Authenticated Shopify CLI session:
shopify store auth --store <domain> --scopes read_orders,read_customers - API scopes:
read_orders,read_customers
Parameters
| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
| store | string | yes | — | Store domain (e.g., mystore.myshopify.com) |
| days_back | integer | no | 30 | Lookback window for orders to attribute |
| ad_spend | object | no | {} | Map of source name → spend in store currency, e.g. {"google": 4500, "meta": 3200, "tiktok": 1800} |
| new_customers_only | bool | no | true | Count only first-order customers as "acquired" |
| min_orders_per_source | integer | no | 5 | Minimum orders for a source to be reported |
| format | string | no | human | Output format: human or json |
Safety
ℹ️ Read-only skill — no mutations are executed. Safe to run at any time. Ad spend values are caller-provided; this skill does not pull from any ad platform.
Workflow Steps
-
OPERATION:
orders— query Inputs:query: "created_at:>='<NOW - days_back days>'",first: 250, selectcustomer { id, numberOfOrders },customerJourneySummary { firstVisit { landingPage referrerUrl source } },landingPageUrl,referrerUrl,totalPriceSet, pagination cursor Expected output: All orders in the window with referral and customer attribution; paginate untilhasNextPage: false -
Group orders by normalized source. Resolution order:
customerJourneySummary.firstVisit.sourceif present- Else parse domain from
referrerUrl - Else parse
landingPageUrlUTM params (utm_source) - Else bucket as
direct
-
If
new_customers_only: true, drop orders wherecustomer.numberOfOrders > 1so each customer is counted once -
Aggregate per source:
orders_count,new_customers_count,revenue_attributed -
Join with
ad_spendmap:cac = ad_spend[source] / new_customers_count. Sources without spend data reportcac: null(organic / unattributed) -
Filter to sources with
orders_count >= min_orders_per_source
GraphQL Operations
graphql# orders:query — validated against api_version 2025-01 query OrdersWithAttribution($query: String!, $after: String) { orders(first: 250, after: $after, query: $query) { edges { node { id name createdAt landingPageUrl referrerUrl customerJourneySummary { firstVisit { landingPage referrerUrl source sourceType utmParameters { source medium campaign } } } totalPriceSet { shopMoney { amount currencyCode } } customer { id numberOfOrders } } } pageInfo { hasNextPage endCursor } } }
Session Tracking
Claude MUST emit the following output at each stage. This is mandatory.
On start, emit:
╔══════════════════════════════════════════════╗ ║ SKILL: Customer Acquisition Cost by Source ║ ║ Store: <store domain> ║ ║ Started: <YYYY-MM-DD HH:MM UTC> ║ ╚══════════════════════════════════════════════╝
After each step, emit:
[N/TOTAL] <QUERY|MUTATION> <OperationName> → Params: <brief summary of key inputs> → Result: <count or outcome>
On completion, emit:
For format: human (default):
══════════════════════════════════════════════ CAC BY SOURCE (<days_back> days) Orders analyzed: <n> New customers acquired: <n> Total ad spend (input): $<amount> Blended CAC: $<amount> By Source (sorted by CAC ascending): google Customers: <n> Spend: $<n> CAC: $<n> meta Customers: <n> Spend: $<n> CAC: $<n> direct Customers: <n> Spend: — CAC: organic referral Customers: <n> Spend: — CAC: organic Output: cac_by_source_<date>.csv ══════════════════════════════════════════════
For format: json, emit:
json{ "skill": "customer-acquisition-cost-by-source", "store": "<domain>", "period_days": 30, "orders_analyzed": 0, "new_customers": 0, "blended_cac": 0, "currency": "USD", "by_source": [], "output_file": "cac_by_source_<date>.csv" }
Output Format
CSV file cac_by_source_<YYYY-MM-DD>.csv with columns:
source, orders_count, new_customers_count, revenue_attributed, ad_spend, cac, currency
Error Handling
| Error | Cause | Recovery |
|---|---|---|
THROTTLED | API rate limit exceeded | Wait 2 seconds, retry up to 3 times |
Empty ad_spend | No spend provided | Report orders / customers per source with cac: null |
Missing customerJourneySummary | Older orders or guest checkout | Fall back to referrerUrl → landingPageUrl → direct |
All orders from direct | No referrer captured | Likely tracking misconfiguration — surface as warning |
Best Practices
- Provide ad spend for the same window as
days_back— mismatched windows produce misleading CAC numbers. - Pair with
customer-cohort-analysisto validate that low-CAC sources also produce high-LTV customers. - Sources reported as
directoften hide attribution leakage — investigate UTM tagging and referrer policies before drawing conclusions. - Treat output as estimated CAC — Shopify's first-touch attribution does not capture cross-device journeys, so sources that rely on view-through (display, video) will be undercounted.
- Re-run weekly to catch CAC drift before campaigns become unprofitable.


