# Gross Margin Return on Inventory – Adjacent Period Changes

> Gross Margin Return on Inventory – Adjacent Period Changes is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-19).

Calculates period-over-period changes in Gross Margin Return on Inventory (GMROI) across a sequence of supplied retail data rows.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-sector-retail-inventory-margin-return-period-changes?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/gross-margin-return-on-inventory-adjacent-period-changes-c3351d1a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UFUGaEzzRcZSRDwMl7jhE

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability gross-margin-return-on-inventory-adjacent-period-changes-c3351d1a -d '<json body>'
```

Example prompt: I have four periods of retail data — gross profits of 5000, 5500, 4800, 6000 and average inventory costs of 2500, 2750, 2400, 3000 — can you calculate the adjacent period changes in Gross Margin Return on Inventory across those periods?

## When to prefer this

Choose this endpoint when you need to analyze how Gross Margin Return on Inventory (GMROI) shifts between consecutive retail periods using your own supplied figures, without needing live inventory feeds or platform integrations. It is ideal for scenario modeling, historical trend reviews, and periodic retail performance audits where the input data is already known.

## Known failure modes

- Missing required fields: if gross_profit or average_inventory_cost is absent from any row, the request will be rejected
- average_inventory_cost must be strictly greater than zero (exclusiveMinimum), a zero value will cause validation failure
- Fewer than 2 rows supplied: minimum row count is 2 for adjacent period comparison to be meaningful
- More than 200 rows: request exceeds maxItems limit and will be rejected
- Values outside the allowed numeric range (±1 trillion) will fail schema validation

## How this service works

Gross margin return on inventory - Adjacent period changes: Adjacent period changes for Gross margin return on inventory. Supplied retail figures only. Local calculation and scenario analysis; no live inventory, account access, platform fee lookup or order execution. One of 25 profiles or calculations across 20 shared operations in this sector. 0.01 USDC includes one bounded adjacent period changes deliverable.

## Output

Returns a structured report showing the computed Gross Margin Return on Inventory (GMROI) for each supplied period and the delta or change between each adjacent pair of periods, enabling trend and scenario analysis without any live inventory or platform integration.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "rows": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "gross_profit",
     "average_inventory_cost"
    ],
    "properties": {
     "gross_profit": {
      "type": "number",
      "default": 5000,
      "maximum": 1000000000000,
      "minimum": -1000000000000
     },
     "average_inventory_cost": {
      "type": "number",
      "default": 2500,
      "maximum": 1000000000000,
      "minimum": 0,
      "exclusiveMinimum": 0
     }
    },
    "additionalProperties": false
   },
   "default": [
    {
     "gross_profit": 5000,
     "average_inventory_cost": 2500
    },
    {
     "gross_profit": 5500,
     "average_inventory_cost": 2750
    },
    {
     "gross_profit": 5000,
     "average_inventory_cost": 2500
    },
    {
     "gross_profit": 5500,
     "average_inventory_cost": 2750
    }
   ],
   "maxItems": 200,
   "minItems": 2
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/gross-margin-return-on-inventory-adjacent-period-changes-c3351d1a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)