Purpose
Quantifies the full cost of returns over a window — not just the refunded amount. Combines refund totals, lost shipping revenue, COGS for non-restockable items (e.g., DEFECTIVE), and restocking labor into a per-reason and per-product return P&L. Read-only. Use to prioritize which reasons or product lines deserve operational fixes — better packaging, size guides, listing accuracy.
Prerequisites
shopify store auth --store <domain> --scopes read_orders,read_returns,read_inventory- API scopes:
read_orders,read_returns,read_inventory
Parameters
| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
| store | string | yes | — | Store domain (e.g., mystore.myshopify.com) |
| format | string | no | human | Output format: human or json |
| days_back | integer | no | 90 | Lookback window for returns |
| group_by | string | no | reason | Aggregation level: reason, product, sku, or reason_x_product |
| min_returns | integer | no | 3 | Minimum returns per group to include in summary |
| writeoff_reasons | array | no | ["DEFECTIVE"] |
Return reasons whose items are treated as non-restockable (full COGS write-off) |
| flat_restocking_cost | float | no | 5.00 | Average labor cost per return line item to model restocking workload |
Safety
ℹ️ Read-only skill — no mutations are executed. Cost figures are estimates derived from
unitCost, refund totals, andflat_restocking_cost— calibrate the flat-cost figure to your operation before treating outputs as accounting truth.
Workflow Steps
OPERATION:
returns— query Inputs:query: "created_at:>='<NOW - days_back days>'",first: 250, select returns with line item pricing, product/variant,inventoryItem.idExpected output: All returns in window with per-line-item pricingOPERATION:
orders— query Inputs: For each return'sorder.id, fetchrefunds { totalRefundedSet refundLineItems { quantity subtotalSet totalTaxSet lineItem { id } } }Expected output: Refund amounts mappable to line itemsOPERATION:
inventoryItems— query — batch uniqueinventoryItem.idfrom step 1; returnsunitCostper itemPer line item compute:
refund_amount(matched refundLineItem proportional to returned qty),shipping_loss(order shipping × line-item value share for full-order returns; else 0),cogs_writeoff(unitCost × qtyonly ifreturnReason in writeoff_reasons),restocking_labor(flat_restocking_cost × qty). Sum and aggregate bygroup_by.
GraphQL Operations
# returns:query — validated against api_version 2025-01
query ReturnsForCostAttribution($query: String!, $after: String) {
returns(first: 250, after: $after, query: $query) {
edges {
node {
id
status
createdAt
totalQuantity
order {
id
name
totalShippingPriceSet { shopMoney { amount currencyCode } }
totalPriceSet { shopMoney { amount currencyCode } }
}
returnLineItems(first: 50) {
edges { node {
id
quantity
returnReason
fulfillmentLineItem { lineItem {
id
title
quantity
discountedTotalSet { shopMoney { amount currencyCode } }
originalUnitPriceSet { shopMoney { amount currencyCode } }
variant { id sku inventoryItem { id } }
product { id title vendor }
} }
} }
}
}
}
pageInfo { hasNextPage endCursor }
}
}
# orders:query — validated against api_version 2025-01
query OrderRefundsForReturns($query: String!, $after: String) {
orders(first: 250, after: $after, query: $query) {
edges {
node {
id
name
refunds {
id
createdAt
totalRefundedSet { shopMoney { amount currencyCode } }
refundLineItems(first: 50) {
edges { node {
quantity
subtotalSet { shopMoney { amount currencyCode } }
totalTaxSet { shopMoney { amount currencyCode } }
lineItem { id }
} }
}
}
}
}
pageInfo { hasNextPage endCursor }
}
}
# inventoryItems:query — validated against api_version 2025-01
query InventoryUnitCosts($ids: [ID!]!) {
nodes(ids: $ids) {
... on InventoryItem {
id
unitCost { amount currencyCode }
tracked
}
}
}
Session Tracking
Claude MUST emit the following output at each stage. This is mandatory.
On start, emit:
╔══════════════════════════════════════════════╗
║ SKILL: Return Cost Attribution ║
║ 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):
══════════════════════════════════════════════
RETURN COST ATTRIBUTION (<days_back> days, group: <group_by>)
Returns analyzed: <n>
Total return cost: $<amount> (refund <pct>%, shipping <pct>%, COGS <pct>%, labor <pct>%)
Top cost drivers:
<group> Returns: <n> Total: $<n> Avg: $<n> Top reason: <reason>
Output: return_cost_<date>.csv
══════════════════════════════════════════════
For format: json, emit:
{
"skill": "return-cost-attribution",
"store": "<domain>",
"period_days": 90,
"group_by": "reason",
"returns_analyzed": 0,
"totals": {
"total_cost": 0, "refund": 0, "shipping_loss": 0,
"cogs_writeoff": 0, "restocking_labor": 0, "currency": "USD"
},
"groups": [],
"output_file": "return_cost_<date>.csv"
}
Output Format
CSV file return_cost_<YYYY-MM-DD>.csv with columns:
group_key, return_count, units, refund_amount, shipping_loss, cogs_writeoff, restocking_labor, total_cost, avg_cost_per_return, top_return_reason, currency
Error Handling
| Error | Cause | Recovery |
|---|---|---|
THROTTLED |
API rate limit exceeded | Wait 2 seconds, retry up to 3 times |
Missing unitCost |
Cost not recorded | Treat COGS as 0 and flag the row |
| Refund not yet processed | Customer not yet refunded | Use line item discounted total as estimate |
| Multiple refunds per return | Partial refund history | Sum refunds tied to the return's line items |
| No shipping cost | Free shipping | Shipping loss = 0 |
Best Practices
- Use
group_by: reason_x_productto surface lethal combos likeDEFECTIVE × <hero SKU>— supplier-quality issues addressable at the source. - Re-run after
unitCostupdates; stale cost most often skews COGS write-off. - Pair with
return-reason-analysisto compare "what returns most" with "what costs most" — they often diverge.