# Inventory Safety Stock & Reorder Point (ROP) Calculator

> Inventory Safety Stock & Reorder Point (ROP) Calculator is a paid API for AI agents from x402-niche-briefs.fly.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-30).

Computes safety stock units, days of cover, reorder point trigger, and recommended 60-day PO quantity from daily sales velocity, supplier lead time, and target service level.

## Facts

- Endpoint: GET https://x402-niche-briefs.fly.dev/v1/reorder-point-safety-stock?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/inventory-safety-stock-reorder-point-rop-calculator-8d83c2b5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2YmJ546Fi6P-LUzFUMvHw

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 inventory-safety-stock-reorder-point-rop-calculator-8d83c2b5
```

Example prompt: Calculate my reorder point and safety stock for a product that sells 15 units per day with a 35-day supplier lead time — I want a 95% in-stock service level.

## When to prefer this

Use this endpoint when you need a fast, deterministic, formula-based safety stock and ROP calculation for long-lead-time supply chains (import, overseas manufacturing) without needing historical demand data or probabilistic simulation. Ideal for ecommerce operators, Amazon sellers, and importers who want a quick, defensible inventory target from three simple inputs.

## Known failure modes

- Missing required parameters daily_units or lead_time_days returns an error
- service_level_pct outside 50–99.9 range may produce unexpected Z-score results
- Non-numeric string values for numeric fields may cause computation failure
- Very high lead times or service levels may produce extremely large safety stock recommendations that should be validated manually

## How this service works

Deterministic inventory safety stock and Reorder Point (ROP) calculator for long-lead-time supply chains. Pass ?daily_units=15&lead_time_days=35&service_level_pct=95. Computes Z-score buffer across combined demand and lead-time variance, returning safety stock units, days of cover, ROP trigger units, and 60-day PO quantity.

## Output

Returns a JSON object with: the input echo (daily_units, lead_time_days, service_level_pct), assumptions used (Z-score, assumed demand CV%, assumed lead-time CV%), and computed inventory_targets including lead_time_demand_units, safety_stock_units, safety_stock_days_of_cover, reorder_point_rop_units, reorder_trigger_days_of_stock_remaining, and recommended_60_day_order_qty_units.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "daily_units",
      "lead_time_days"
     ],
     "properties": {
      "daily_units": {
       "type": "string",
       "description": "Average daily unit sales velocity"
      },
      "lead_time_days": {
       "type": "string",
       "description": "Supplier production + transit lead time in days"
      },
      "service_level_pct": {
       "type": "string",
       "description": "Target in-stock service level percentage (50-99.9, default 95)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "$schema": "https://json-schema.org/draft/2020-12/schema",
     "required": [
      "as_of",
      "inputs",
      "assumptions",
      "inventory_targets"
     ],
     "properties": {
      "as_of": {
       "type": "string"
      },
      "inputs": {
       "type": "object",
       "required": [
        "daily_units",
        "lead_time_days",
        "service_level_pct"
       ],
       "properties": {
        "daily_units": {
         "type": "number"
        },
        "lead_time_days": {
         "type": "number"
        },
        "service_level_pct": {
         "type": "number"
        }
       }
      },
      "assumptions": {
       "type": "object",
       "required": [
        "z_score",
        "assumed_daily_demand_cv_pct",
        "assumed_lead_time_cv_pct"
       ],
       "properties": {
        "z_score": {
         "type": "number"
        },
        "assumed_lead_time_cv_pct": {
         "type": "number"
        },
        "assumed_daily_demand_cv_pct": {
         "type": "number"
        }
       }
      },
      "inventory_targets": {
       "type": "object",
       "required": [
        "lead_time_demand_units",
        "safety_stock_units",
        "safety_stock_days_of_cover",
        "reorder_point_rop_units",
        "reorder_trigger_days_of_stock_remaining",
        "recommended_60_day_order_qty_units"
       ],

… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/inventory-safety-stock-reorder-point-rop-calculator-8d83c2b5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-niche-briefs.fly.dev](https://www.zero.xyz/host/x402-niche-briefs.fly.dev/llms.txt)